New Energy Vehicle High Voltage Fast Charging Industry Research: The Next New Trend of Electric InteIssuing time:2024-04-01 16:09 New Energy Vehicle High Voltage Fast Charging Industry Research: The Next New Trend of Electric Intelligence in Discharge 1, high-voltage fast charging or the next phase of the better complementary energy program 1.1, the essence of fast charging is to improve the charging side of the power and battery charging and discharging times DC Fast Charging: Solving Range Anxiety and Broadening EV Use Scenarios DC fast charging shortens the charging time significantly compared to AC slow charging, expanding the short-distance urban use scenarios to long-distance travel scenarios. Currently, there are two main charging methods for electric vehicles, DC fast charging and AC slow charging. AC slow charging corresponds to the charging scenarios at home or in the parking lot of a community, with a small charging power ranging from a few kilowatts to tens of kilowatts, and usually takes 8-10 hours to fully charge. AC slow charging directly uses AC power from the grid, and through the on-board charger OBC, the AC power is converted into DC power and supplied to the battery of the electric vehicle; DC fast charging generally corresponds to the charging scenarios on the highway/long-distance journey, with a power of hundreds of kilowatts, and only takes 1-2 hours to fully charge. DC fast charging, on the other hand, generally corresponds to the charging scenarios on highways/long journeys, with a power of hundreds of kilowatts, and it only takes 1-2 hours to be fully charged. In recent years, with the accelerated penetration of new energy vehicles around the world, a number of companies have laid out super fast charging technology, with the peak power of fast charging reaching 350kW or even 480kW, and the super fast charging time is expected to be lowered to less than 30 minutes, and in the future, it may be further compressed to less than 15 minutes or even 10 minutes.
The essence of DC fast charging is to transfer high power AC/DC to fast charging post. AC slow charging mainly relies on home AC charging pile charging, direct use of grid 220V AC power, EV through the car charger OBC internal AC/DC converter will be converted from grid AC power to DC power supply power battery, due to the charging power is low, car OBC built-in AC/DC converter power is generally low, low cost; DC charging pile and AC charging pile the biggest difference is that the AC/DC converter will be moved to the charging pile, the AC/DC converter in its internal conversion into high power DC power to provide. The biggest difference between DC charging pile and AC charging pile is that the AC/DC converter is moved into the charging pile, and the AC power from the grid is converted into high-power DC power to be supplied to the on-board power battery in the vehicle, which requires high-power AC/DC converter, and its volume and cost rise at the same time, with diminishing marginal benefit. Increase fast charging speed: need to increase the power of the charging side and the battery charging/discharging multiplier at the same time The effective charging power is the smaller of the charging power and the battery charging power. To increase the fast charging speed, both the charging power and the battery charge/discharge multiplier need to be increased at the same time. Charging power (equation P = UI) is increased by increasing voltage or current. Power is equal to the product of voltage and current, i.e. 1W = 1V*1A. Increasing charging power can be achieved by increasing voltage or current. Tesla is a typical representative of the high-current route, with a charging voltage of 400V at the super charging pile, and by 2022, the current of its fourth-generation super charging pile will reach 900A, and the peak charging power will reach 350kW; Porsche Taycan is the first model to lay out a high-voltage platform of 800V, and as a typical representative of the high-voltage route, its peak charging power has reached 350kW. Charge Rate (also called C multiplier) corresponds to the speed of power battery charging and discharging, and its enhancement has high requirements on the overall performance of power battery. C represents the total capacity of the battery, and xC means that one hour charging time can be filled up with x times of the total battery capacity, and the bigger the value of x is, the shorter the full-charging time is. Charging rate increase depends on the related technologies, including cell materials, internal structure of the cell, module design program, battery pack design program CTP (Cell to Pack) and battery management system BMS and other continuous breakthroughs. At present, domestic mainstream battery companies are promoting the power battery charging and discharging multiplier from 1-2C to 4C, and there are already models equipped with 3C charging multiplier batteries in the market, while the new Kirin CTP3.0 batteries released by Nintime will raise the charging multiplier to 4C. As the multiplier is raised to 4C or above, the marginal benefit of the multiplier increase is getting lower and lower.
1.2. Fast charging solutions may be superior to switching and high-capacity batteries Compared with the development history of cell phone energy supplement, fast charging may become the mainstream solution for EV energy supplement. With the improvement of cell phone intelligence, the power consumption of cell phone increases rapidly, and fast charging becomes the mainstream solution for smart phones to solve the battery life anxiety; EV battery life anxiety affects the EV use scenario, and the current power exchange, large-capacity battery, and fast charging solutions are all aimed at realizing a more convenient replenishment of EVs, thus enhancing the consumption demand of EVs. Comparing the three solutions, fast charging may be the better energy replenishment solution. Option 1. Power exchange: A certain degree of battery standardization is needed, and large-scale promotion faces challenges. In the Nokia era, cell phones were mostly replenished by battery replacement. For electric vehicles, Azalea first set up about 700 power exchange stations in China, providing customers with the service of replacing car batteries within 3-5 minutes. The swap solution requires a certain degree of standardization of power batteries, which makes it easier to replace them and promote them on a large scale. Considering factors such as the rapid update of battery technology, the high degree of differentiation of power batteries among automobile enterprises, the relatively high cost of batteries, and the large investment in assets for the construction of power exchange stations, the promotion of the power exchange program may face greater challenges. Scenario 2: Large-capacity batteries will further increase their capacity, and technology and cost will face great challenges. As cell phones enter the smartphone era, power consumption speeds up, and improving the battery life of cell phones is crucial to consumer experience. iPhone 6 to iPhone 13, the battery capacity has increased from 1810mAh to 3227mAh, and in the 5G era, a number of cell phones have already improved their batteries to 5000mAh, such as the Huawei Enjoy 20, but large-capacity batteries need to be sacrificed to make cell phones slimmer and lighter and to increase the weight of cell phones. The impact on the feel of the phone. The last stage of solving the mileage anxiety of electric vehicles was also to improve the capacity of power batteries, but with the increase in battery capacity, the marginal benefit is getting lower and lower, and considering the difficulty of marginal improvement of technology, the cost is rising rapidly. The solution to the range problem of fuel cars is not to rely on increasing the size of the fuel tank, but a convenient way to replenish energy through refueling.
Program 3. Fast charging may become a better solution for electric vehicle energy replenishment in the next stage. Cell phone to iPhone, for example, its 5V1A/5W charging power lasted nearly 10 years, to 2017 for the first time to support PD fast charging, charging power increased to 18W, 2021 iPhone 13 Pro Max charging power reached 20W, charging 50% of the power in about 35 minutes. 1.3 High voltage is expected to become the mainstream fast charging route Compared with high-current mode, high-voltage mode has the advantages of larger efficient charging area, higher charging power ceiling and lower technical difficulty, which is expected to become the mainstream fast charging route at this stage. Fast charging based on high voltage can realize higher charging power at a larger SOC; high current mode with the same peak charging power has a smaller SOC area for efficient charging, and the charging power drops rapidly in other areas. Tesla adopts the 400V high-current route, and the fourth generation fast charging current will be increased to about 900A, and the high current in the circuit will generate high heat loss (according to the formula of heat generation Q=I^2*R*t), and the heat generated by the resistors of the connectors, cables, connections of batteries, bus bar rows and so on will increase in the square level, which leads to the fact that although the peak charging power is high, the average power is not high, and the charging power ceiling is lower than that of the high-voltage route. The charging power ceiling is lower than that of the high voltage route. High-voltage and high-current routes are relative concepts within a certain period of time, and both modes are essentially designed to increase charging power. Tesla developed 400V fast charging earlier, which was also considered as a high voltage route in the early stage, and in order to further increase the charging power, it took measures to keep the voltage platform unchanged and increase the current; 800V high-voltage platform is applying more and more current with the constant iteration of technology by car companies. Compared with 400V, the 800V platform can achieve the same peak charging power with a smaller current. The fact that high voltage has become the mainstream route means that at this stage, companies are focusing on developing 400V platforms to upgrade to 800V platforms, rather than solely focusing on increasing the current to realize the increase in charging power.
800V high voltage has become a stage of industry standard, and will evolve to 1000V-1500V in the future. based on the direction of high power charging research, global fast charging standards are evolving towards standardization and integration. The super charging standard will be released in 2021, and China and Japan are unifying the Asian fast charging standard, with the maximum charging power evolving from 400kW (400A/1000V) and 250kW (250A/1000V) to 900kW (600A/1500V), while the maximum charging power in Europe and America is evolving from 200kW (200A/1000V) and 120kW (200A/600V) to 460kW (600A/1000V) respectively. 200A/600V) to 460kW (500A/920V), respectively. Porsche's Taycan model launched in 2019 is equipped with the 800V platform for the first time, and since upgrading the voltage level involves upgrading the performance of high-voltage components and the safety performance of the electrical system of the entire vehicle, the upward evolution of high-voltage platforms and technology iteration are in a staged development mode.2021 Huawei said that it will launch a fast charging solution with a voltage platform of over 1000V/600kW in 2025, which will realize 30%-80% SOC charging in 5 minutes. In 2021, Huawei said it would launch a fast charging solution with a voltage platform of over 1000V/600kW in 2025, realizing 30%-80% SOC charging performance in 5 minutes. Currently, mass-produced models based on the complete 800V architecture are represented by the Porsche Taycan and the Hyundai Kia Ioniq-5, while the 800V platforms of other companies are mostly 400V battery series-parallel transition programs. The complete 800V program refers to the input/output of 800V from a single power pack, while most companies currently use two 400V batteries in series-parallel connection to be compatible with both 800V and 400V (800V in series and 400V in parallel), with flexible outputs switched by relays, in order to quickly lay out the 800V platform. At present, most charging piles are still 400V, and the industry chain of 800V charging piles and 800V vehicle high-voltage components is not perfect in the short term, so enterprises need to consider two points: 1. how to be compatible with 400V charging piles and 800V charging piles; 2. how to be compatible with certain 400V vehicle components. Below is an explanation of the two complete 800V platform architecture options. Porsche program adds DC/DC converter to transition to 800V: Taycan adopts 800V architecture for some high-voltage parts, such as electric drive system, power battery, high-voltage charger, high-voltage auxiliary heating, etc., and is compatible with the 400V DC pile program through the addition of a new DC/DC converter.Taycan provides three charging modes: AC slow charging, 400V DC fast charging and 800V DC fast charging. The Taycan offers three charging options: AC slow charge, 400V DC fast charge and 800V DC fast charge. The Hyundai Kia solution is fully upgraded to 800V: all components of the Ioniq-5 are based on the 800V architecture, including its AC compressor, PTC, charger, external high power charger, etc. All components are based on the 800V system, which is upgraded to be compatible with 400V DC charging piles by the electric drive system. the Ioniq-5 offers 3 charging modes: AC slow charging, 400V DC fast charging. 800V DC fast charging, The Ioniq-5 offers three charging options: AC slow charging, 400V DC fast charging and 800V DC fast charging. 2、Vehicle enterprises intensive layout 800V, 2022 is expected to become the first year of high-voltage fast charging mass production 2.1 400V route: Tesla is the representative of 400V high-current route, and joint-venture brands are rapidly following up. Tesla is the representative of 400V high-current route, leading the early development of fast charging. As early as 2012, Tesla launched its supercharger V1, which could only reach 100kW of fast charging power. By 2022, Tesla's supercharger will have developed into the fourth generation V4, which will be able to reach a peak of 350kW of fast charging power by continuously increasing the current to 900A, and can be used by all Tesla models. BMW's I-Next and I4 models will realize 200kW power fast charging in 2021, and Mercedes-Benz's EQS models will reach about 200kW power charging in 2021. Compared to Tesla and European traditional car companies, American and Japanese traditional car companies are lagging behind. Toyota will launch its first all-electric model, the bZ4X, in 2022 with 150W of fast-charging power, and Honda and Ford will join hands to launch 400V/200kW fast-charging for most of their models through Ford's Ultium platform. 2.2 The 800V Route: Overseas Brands Accelerate Layout, Domestic Autonomous Follows Up Quickly Overseas mainstream automobile enterprises, domestic traditional independent brands and new forces have accelerated the layout of the 800V high-voltage platform, and more 800V models will be listed in 2022, or become the first year of high-voltage fast charging. Overseas, represented by Porsche's Taycan, which will go into production in 2019, the charging power will reach 280kW, and the PPE platform jointly developed by Porsche and Audi will reach a peak charging power of 300kW in 2022; South Korea's Hyundai Kia Ioniq-5 will transform from 400V to 800V in one step, and will reach a charging power of 220kW in 2021, and its second-generation products will reach 260kW in 2023; and the second-generation products will reach 260kW in 2023. Mercedes-Benz and BMW are both transitioning from the 400V route, with Mercedes' MMA 800V platform expected to be operational by 2024 and BMW's NK1 800V platform by 2025; Volvo's SPA2 800V platform is expected to be available by 2024; and Honda and GM are collaborating on a new 800V vehicle based on GM's Ultium platform, which is expected to be available after 2024. Honda and GM are expected to launch an 800V/350kW electric pickup truck after 2024 based on GM's Ultium platform; Lucid Air, a new American force, may launch a luxury pure-electric sedan in 2022 based on the 900V platform (the 750V-1000V belongs to the 800V concept), with a charging power of 350kW.
Among the autonomous traditional automakers, BYD's E platform 3.0 800V will be officially released in 2021, and the Ocean-X concept car based on this platform is expected to be released this year; Geely's Hao Han SEA 800V architecture will be launched in 2021; GAC's AION-V (1000V high-voltage fast charging) and Great Wall's Mechatron are capable of providing fast charging at 480kW; and Dongfeng Lantu is developing an 800V/360kW platform. The 800V/360kW platform is being developed by Dongfeng Lantu. Among the new domestic forces, Huawei has set a target of launching a 1000V 400kW by 2023 and a 1000V 600kW by 2025, and will partner with BAIC to launch the Extreme Fox Alpha S in 2021 with a charging power of 250kW, and with Changan and Nindele Times to launch the Avita 11 in 2022 with a charging power of 230kW at 750V (750V-1000V is part of the 800V concept). 1000V belongs to the 800V concept); Xiaopeng will launch the G9 in 2022 with a charging power of 480kW; Azalea announced at NIOPowerDay2022 that it will release 500kW liquid-cooled super-charging piles, as well as 800V high-voltage platform battery packs, and will open them up to the entire industry; Ideal expects to launch a C-class SUV after 2023 with a charging power of 400kW; Zeropet is currently working on a C-class SUV with a charging power of 400kW. Ideal is expected to launch a C-class SUV after 2023 with a charging power of 400kW; Zerodan is currently developing an 800V platform, which is expected to be launched in Q4 of 2024. 3, 800V high-voltage fast charging drive vehicle electrical system performance and safety comprehensive upgrade 3.1 Influence of core components: upgrading the performance and safety of high-voltage system components. High-voltage fast charging leads to the increase of high power density of the whole vehicle, the operation load is bigger, and the high-voltage system components of the whole vehicle need to be upgraded in terms of performance and safety. In addition to upgrading the materials and design of power battery cells, the electrical system components of the high-voltage part of the whole vehicle need to be upgraded together, mainly in three major aspects. Firstly, the total power of the thermal management system of the whole vehicle has been upgraded and the complexity has been increased; secondly, for the systematic upgrade of the electrical system for high loads, the relevant power devices need to reduce losses and improve efficiency, of which the most obvious trend is to replace Si-based power devices with SiC-based power devices in the large and small triads (with a focus on the replacement of Si IGBTs by SiC MOSFETs in the electronically-controlled inverters); and thirdly, in order to guarantee the safety performance of the automobile under high load, the relevant devices, such as the power cell material and design, need to be upgraded as well. Thirdly, in order to ensure the safety performance of automobiles under high loads, related devices such as digital isolation chips, film capacitors, connectors, fuses, relays and so on are required to be upgraded in terms of both quantity and performance. The upgrades in the three areas are interrelated and have a "chain" reaction. For example, the replacement of Si-based IGBTs with SiC-based MOSFETs will increase the operating power and frequency, and the corresponding isolation drivers will need to be upgraded as well, while the number of film capacitors will need to be increased in order to meet the safety requirements of the electrical system.
Trends and routes of battery packs and cells under fast charging: Under high-voltage fast charging, there is a tendency for copper rows to become thicker between cell modules in battery packs, and the spacing between modules is larger, which reduces the energy density of battery packs to a certain extent. Copper rows are used in battery packs to connect each module in series for the purpose of connecting and conducting electricity. Copper rows have high current and high voltage loads, therefore, under high-voltage fast charging, the thicker the wires are, the lower the resistance is, the lower the heat loss is, which enhances the wire's overload capacity, and at the same time it is not easy to overheat, which enhances safety. Equal cross-sectional area of copper rows have higher current carrying capacity than aluminum rows, which can save space compared to aluminum rows when applied to high-voltage platforms. Under high-voltage fast charging, the charging and discharging multiplier of the battery cell increases, and the expansion force generated during the charging and discharging cycle is even greater. Excessive expansion will lead to deterioration in the performance of the battery cell and life decay, and even destroy the structural framework of the module, and more space needs to be reserved between the battery cell modules to ensure the safety of the power battery. Under high-pressure fast charging, the charging and discharging multiplier of the battery core will be increased, and the ternary lithium battery has the advantage of high energy density, while the lithium iron phosphate battery has the advantage of high security. Currently there are two main camps of battery cell materials, lithium iron phosphate and lithium ternary battery, the two materials used in fast charging have their own advantages, of which the biggest advantage of lithium ternary battery is that the energy density is much greater than lithium iron phosphate, but lithium iron phosphate battery has a strong overcharge and discharge performance and better safety performance; different car models using different battery cell materials, corresponding to the design of the battery cell and battery pack CTP (cell to pack) design program varies. The corresponding cell design and CTP (cell-to-pack) design of battery packs vary from car model to car model. However, these differences are all aimed at achieving the same goal, i.e., to improve energy density, reduce cost, improve safety performance, and improve overcharge/discharge performance. For example, although the BYD blade battery is made of LiFePO4, the innovative "blade" design at the CTP ring improves space utilization and compensates for the lower energy density of the cell itself compared to the ternary cell. Based on different raw materials and supply systems, there are currently two main routes for power batteries: 1. the price-performance route of square batteries with lithium iron phosphate; and 2. the high energy density route of cylindrical batteries with lithium ternary. Generally speaking, although the material cost of square battery with LiFePO4 is lower than that of Li-ion ternary battery, it is necessary to increase the cost and optimize the performance at the CTP ring in order to better apply to high-voltage fast-charging scenarios. Compared with high voltage, battery cells change more under high current route. When fast charging at high current, the total amount of heat generated by the cell increases and is uneven, resulting in a rise in battery temperature; at the same time, lithium precipitation reaction is more likely to occur at the negative electrode due to the high current, significantly lowering the critical temperature of overheating, which makes it easier for thermal runaway to occur. At the same time, the negative electrode is more prone to lithium precipitation reaction due to high current, which greatly reduces the critical temperature of battery overheating, making thermal runaway more likely to occur. Currently, the solution is to improve the anode material: 1. implement a new type of soft carbon/hard carbon coating modification to the original anode graphite material; 2. replace it with silicon carbon anode. Comparatively speaking, the high voltage route requires less change in the battery core. 3.2 Upgrade and iteration of thermal management water-cooling plate and expansion valve and other components 3.2.1 The design of water-cooling plate with battery cell under fast charging becomes the focus of battery thermal management. Architecture change under high-voltage fast charging: water-cooling plate cooling/heating power increase Higher rate battery temperature rise is higher and faster, while the power battery efficient working temperature range is narrower, more efficient battery thermal management is the key to maintain battery performance and safety, water-cooling plate cooling/heating power increase accordingly. 20-35℃ is the efficient working temperature range of the power battery, the battery charging/discharging performance will be reduced due to the temperature being too low (<0℃); too high temperature will create the risk of thermal runaway of the battery, which threatens the safety of the whole vehicle. If the temperature is too low (<0℃), the performance of battery charging and discharging power will be reduced, shortening the range; if the temperature is too high, the risk of thermal runaway of battery will occur, threatening the safety of the whole vehicle. The internal temperature of the battery and the uniformity of the temperature between battery modules affect the performance and cycle life of the battery, so the battery thermal management system usually requires a complex and fine cooling circuit to maintain the temperature consistency of the battery cell. For ordinary electric vehicles, water-cooling panels are usually designed at the bottom of the power battery. As the charging and discharging power rises, the amount of heat dissipation required increases, so it is necessary to increase the contact area between the water-cooling panels and the battery cells, and at the same time, ensure that the battery pack has a high degree of overall integration. There are innovations in the design of water-cooling plate and its structure to match the design of the battery cell. Compared with the design of water cooling plates for batteries requiring high heat dissipation (Tesla 4680 battery), the future trend of water cooling plates for 800V high-voltage fast charging is 1. high-voltage fast charging solutions add vertical water cooling plate structures to be placed in between the battery packs, and even water cooling plates are added to the top of the batteries. 2. Mezzanine-type vertical water cooling plates are involved in the battery pack components, and different companies have made different integrated designs of water cooling plates according to the structural design of the internal structure of the battery packs, so that the water cooling plates are integrated with the battery packs. Different companies have integrated the water cooling plates in different ways for the internal structural design of their battery packs, giving them a multifunctional character. Although the Hyundai Ioniq and Porsche Taycan are 800V platforms, the amount of water-cooling panels used and their design are relatively conservative compared to Tesla's 400V platform because Tesla's fourth-generation supercharger will have a peak charging current of 900A, which will require greater heat dissipation. With the development of 800V platform, the charging power will increase, and the heat dissipation will increase. Kirin's newly released CTP3.0 battery multiplier reaches 4C, which will be applied to high voltage solutions in the future, and its water-cooling board design is in line with the trend of high heat dissipation performance. 3.2.2, large-diameter high-precision electronic expansion valve is expected to become the industry technology trends Architectural changes under high-voltage fast charging: electronic expansion valve flow rate control range increased The cooling/heating power of thermal management rises under high-voltage fast charging, and the range of refrigerant flow rate control by the electronic expansion valve needs to be improved and high accuracy needs to be ensured. Demand comes from: 1. Fast charging performance and battery energy storage performance are greatly reduced under low temperature, and more heat production is needed through refrigerant to ensure the working efficiency of core components; 2. Temperature rises faster under high-voltage fast charging, and the demand for heat dissipation increases, which requires an increase in the cooling capacity and cooling speed of refrigerant; 3. The temperature range for the power battery to work efficiently is narrow, which requires precise control of cooling/heating capacity.
Electronic Expansion Valves require a larger bore size for control of large flow rate ranges. According to the Carel product technical documentation, electronic expansion valves must be sized according to the cooling capacity of the evaporator they serve. Valve sizes that are too small will usually have higher superheat than the set point (small bore is not resistant to high pressure). Larger valve sizes increase the high pressure resistance, but the precise flow control (especially for small flow rates) is reduced and the system is prone to "destabilization" problems, i.e., there can be wide variations in temperature, pressure and superheat, and refrigerant backflow to the compressor can also occur. When the cooling/heating capacity under fast charging becomes larger, the flow rate range of electronic expansion valve control flow becomes larger, without increasing the number of valves, the large diameter can meet a larger range of flow control, but the large diameter is easy to cause a reduction in accuracy. High precision comes from the electronic expansion valve systematic design capability. The difficulty of large-diameter electronic expansion valves does not lie in the caliber itself, but in ensuring high control accuracy while increasing the valve caliber. A major advantage of electronic expansion valves over conventional thermal expansion valves used in fuel-efficient vehicles is the ability to precisely control the temperature through the controller. The electronic expansion valve is connected to a sensor that monitors the temperature and differential pressure in real time, which is set by the controller chip and fed back to the electronic expansion valve motor to control the caliber action, using a control algorithm that calculates the position of the valve brake in real time and controls the driver to drive the internal stepping motor to act together to achieve the purpose of throttling. Improvement of accuracy can be achieved by upgrading the systematic design of the sensor and controller, including the sensitivity of the sensor itself and the algorithm of the controller chip; higher sensitivity can also be achieved through innovative design of the valve caliber. Large-diameter needle valves can improve the accuracy of flow control. Needle valves and ball valves for electronic expansion valves used in two types of valves, needle valve spool is a pointed cone, the general shape of the needle valve than other types of valves stronger pressure capacity, better sealing, generally used for higher pressure gas or liquid media sealing, while having a high degree of accuracy of flow control. Compared with larger diameter needle valve, ball valve disadvantage is 1. flow control accuracy deviation; 2. is a combination of gear parts, the product is difficult to achieve consistency; 3. ball valve life is relatively shorter than needle valve. However, ball valves relative to other types of valves have the advantages of rapid throttling, low fluid resistance, simple structure, stability and reliability, wide range of applications, so they are also widely used in the expansion valve. Electronic expansion valves have a tendency to integrate functions, making the refrigerant circuit simpler. Large-diameter electronic expansion in the large opening can control the large flow, small opening can meet the small flow precision adjustment, and at the same time has a two-way cut-off function, set of electronic expansion valves, solenoid valves, check valves in one, can be replaced in the refrigeration circuit to heat pumps in the two traditional expansion valves, so that refrigerant circuits are simpler, more integrated. Competition in the industry: electronic expansion valve industry technology threshold is higher, compared with the globe valve, four-way valve, thermal expansion valve and other traditional valves market concentration is higher. Electronic expansion valve R & D technology gate indicators require high requirements, such as leakage, maximum operating pressure difference, hydraulic strength, flow regulation covering a wide range of indicators, low noise, small size, impurity resistance, high life expectancy, and manufacturers need to have the ability to design the system. 2020 before the three major brands of automotive electronic expansion valves market share as high as 93% of the foreign-funded Fudanji machine, the domestic brands for the three flowers of Intelligent Controls and Shield Ann environment.
Established in 1949, FUJIKOKU is a leading manufacturer of refrigeration components in Japan, starting with expansion valves. FUJIKOKU's refrigeration and air-conditioning system components, such as automatic temperature expansion valves, globe valves, drain pumps, electronically controlled expansion valves, solenoid valves, etc., are used in the automotive, commercial appliance and household appliance industries, and FUJIKOKU established a joint venture with SANKA in 1994 to develop SANKA FUJIKOKU, which has the widest range of electronic expansion valves in the industry. SANHUA has been deeply cultivated in the electronic expansion valve industry, with the most complete product specifications and the widest application. SANFA was founded in 1984 as a refrigeration parts company and has grown to become a leading global supplier of air conditioning and refrigeration parts. Sanhua entered the automotive industry earlier with refrigerant valve products, and the proportion of automotive parts business is gradually increasing, accounting for about 30% in 2021, and its thermal management products cooperate with well-known automotive customers such as Tesla, GM, BMW, Volvo, Ulai, BYD, and so on. Shion Environment has 20 years of experience in the research and development of electronic expansion valves, with leading technology, and large-diameter electronic expansion valves have entered the mass production stage. Shion and Sannhua have monopoly in the field of household air-conditioning valves, and have entered the new energy automobile refrigerant valve industry with the advantage of valve technology. At present, Shion's mass-produced electronic expansion valves are ahead of the industry in terms of silencing, miniaturization, reliability, and high energy efficiency. 3.3, SiC accelerated replacement of Si used in power devices, price and volume increase Architecture change under high-voltage fast charging: SIC replaces IGBT SiC MOSFETs are used in inverters. Compared with Si IGBTs, SiC MOSFETs have the advantages of high voltage and high temperature resistance, small size, high frequency, and low loss, which are suitable for high-voltage fast-charging platforms and improve power conversion efficiency. IGBT, which is Si material by default, is the core power device of inverter, which is essentially a power switch that can output or disconnect high power current by inputting a small power control signal, so as to convert high power DC power to high power AC power for motor use. IGBT, which is evolved from BJT and MOSFET, has the advantages of both of them, and has the ability to resist high voltage and current, which makes it more suitable for automotive applications than the latter two. IGBTs evolved from BJTs and MOSFETs and have the advantages of both, being resistant to high voltage and high current, and more suitable for high power in automobiles than the latter two. However, IGBTs are not without their drawbacks. As a bipolar device, compared with MOSFET unipolar devices, there is a trailing current when shutting down, high shutdown loss, Si IGBTs can withstand high voltages of about 600V, which cannot meet the trend of accelerated upgrading of the high-voltage platform to 800V or even more than 1,000 V. The SiC solution is to upgrade Si MOSFETs to SiC materials, which is a third-generation semiconductor material that has emerged in recent years. The SiC solution is to upgrade Si MOSFETs to SiC material, which is a third-generation semiconductor material emerging in recent years. SiC is a wide-band semiconductor material, which can achieve very high withstand voltage, and the chip is also very thin, capable of withstanding higher voltages of 800V and above. Compared with Si IGBTs, the on-resistance and switching loss are greatly reduced, which improves the energy conversion efficiency in high-power and high-frequency operation.
The main applications of SiC to Si in EVs involve inverters for electric drives, DC/DC converters, OBCs for on-board chargers, and charging posts. The most important increments come from inverters and charging piles. Wolfspeed forecasts that motor-drive inverters will continue to dominate the new energy vehicle SiC device market through 2026. The number of SiC MOSFETs used in inverters far exceeds that of other components such as OBCs and DC/DCs, and the trend of SiC substitution in motor-drive inverters is more obvious and leading. SiC is used in small triple-converter and charging piles, which are relatively less core and less important than the electronic control inverters, and OEMs have a greater incentive to outsource them, which will bring more opportunities to domestic third-party vendors. SiC is used in high-voltage to low-voltage DC/DC converter, as well as the new 400V boost 800V DC/DC converter, which can reduce power loss and reduce the size of the converter; SiC is used in OBC and charging piles, especially the charging piles under high power load, which can also improve the efficiency, reduce the loss and reduce the size, and the material cost of SiC is lower than Si (Wolfspeed), which is more important than Si, and will give domestic third-party manufacturers more opportunities. After an initial period of higher R&D costs, the material cost of SiC is lower than that of Si (Wolfspeed). These components are less centralized than electronic controls, so automakers have more incentive to outsource them, and third-party companies that can meet the high-voltage needs of automakers will have a competitive advantage. OBC charging power is also on the rise, from 3.3kW to 22kW. SiC applied to OBCs has less power loss and faster charging speed through OBCs, which, considering the reduction of loss and the improvement of efficiency, will reduce the cost of OBCs as a whole, as well as reduce their size and weight in the future. According to Wolfspeed, by applying SiC to 22kW bi-directional OBCs to replace Si, the SiC system can achieve 97% peak system efficiency at a power density of 3 kW/L, while Si OBCs can only achieve 95% efficiency at a power density of 2 kW/L, more than doubling the switching frequency. The switching frequency is more than doubled. Also, Si power devices require the use of 24 devices compared to 14, and the performance of SiC devices reduces the number of other components required, resulting in a lower overall cost despite the higher cost of individual SiC devices. High-power fast charging pile in silicon carbide device penetration rate is low, future growth space is broad. SiC MOSFET and diode products with high temperature and high pressure, high frequency advantages, compared with the application of Si-based devices can be used in charging pile charging pile efficiency up to 97%, reduce the loss of up to 50%, and enhance the stability of the charging device. Short-term due to SiC production capacity limitations, the price is high, but with the capacity to improve, the price is gradually reduced, and the application of SiC can simplify the circuit structure of the DC charging pile, reduce the number of components used, reduce the cost of thermal management, a comprehensive point of view, the application of SiC can be in the future for the construction of fast-charging pile to provide cost advantages. Competition in the industry: OEMs have a stronger tendency to research on their own for the application of SiC in inverters. 2018, Tesla's Model 3 for the first time applied SiC power devices (from STMicroelectronics) to replace the inverter's IGBT module, with a total of 48 SiC MOSFETs integrated into the inverters, and under the same power level, the package size of SiC modules is significantly smaller than that of silicon modules, with 75% lower switching loss and 5 percent higher system efficiency. At the same power level, the package size of SiC module is significantly smaller than that of silicon module, the switching loss is reduced by 75%, and the system efficiency is improved by about 5%. Due to the huge production capacity gap and high price of SiC, BYD researched SiC by itself and started to build a SiC wafer production line with an annual production capacity of 240,000 wafers in 2021, and now BYD Han has successfully equipped with the self-developed SiC MOSFET control module.
The SiC power device market for the automotive industry is forecast to grow at a CAGR of nearly 40% over the next five years, reaching approximately $5 billion in 2027 worldwide. According to Yole, the SiC power device market space will rise from $1.1 billion in 2021 to $6.3 billion in 2027, a CAGR of 34 percent, with the main growth driver coming from the automotive industry; SiC power devices for automotive applications will rise from $700 million in 2021 to $5 billion in 2027, a CAGR of 39 percent. Among the top SiC equipment manufacturers, STMicroelectronics and Wolfspeed will see SiC revenues grow more than 50 percent annually in 2021, in line with the 57 percent growth in the global SiC equipment market. Infineon's SiC entry into the inverter business grew 126 percent, ROHM introduced a SiC-based charging infrastructure solution, and ON Semiconductor is developing SiC power devices and modules for DC charging piles to improve charging efficiency. Domestic third-party manufacturers layout SiC power device products such as electronic control inverter, OBC, DC/DC, etc. Sinovel provides SiC power solutions for new energy vehicles. The company mainly provides 2-in-1 or 3-in-1 products such as on-board power supply OBCs and DC/DC converters, and it is one of the earliest R&D and production enterprises in the world to develop and produce SiC power supply products, and SiC power devices have been fully applied in OBC products of 6.6kW and above. The company's high-power 11kW OBC products have been mass-produced, and can be compatible with global charging standards, providing a competitive advantage for the company to enter the global market, and high-power OBC power supply integration products are in the research and development stage. Our customers include BYD, Volkswagen, Dongfeng Honda, GAC Honda, Hyundai, Xiaopeng Automobile, Great Wall Motor, JAC Motor, BAIC New Energy, Geely Automobile and other famous automobile enterprises. With the combination of hardware and software, high-power silicon carbide, integration and other technological advantages, the share of new energy power supply products will be further increased. According to NE Times New Energy, in 2021, the company's OBC installed capacity totaled 207,000 units, ranking sixth with a market share of about 7.2%, and in April 2022, the market share ranking rose to fifth. Yingboer, Jingjin Electric and Huichuan Technology focus on supporting solutions for electric drive systems and have laid out SiC power devices. With its strong self-research capability and SiC single-tube parallel technology, Inpel realizes high power and high integration, which is small in size and light in weight, facilitates the assembly of the whole vehicle of hybrid models, saves space, has high production efficiency and stable performance. According to the company's announcement, the fourth generation of SiC integrated core powertrain is under smooth research and development, and promote the platform construction, and actively expand the 180kW level of three-in-one products. The company's SiC electronic control has been adopted by Ford and FAW-Volkswagen. JingJin electric core products for new energy vehicles electric drive system, located in the high-end electric drive market, electric drive revenue in 2021 accounted for 80% of the company's total revenue. 2020, the company's third-generation semiconductor high-power SiC controller to obtain the Volkswagen commercial vehicle Traton SiC controller fixed, is expected to be mass-produced in early 2024. The company focuses on the electric drive system market, and has competitive advantages in technology and manufacturing in this field. It is the only enterprise in China that can realize the mass production of four major global vehicle groups in the fields of Si controller and SiC controller at the same time. Currently, Huichuan partially uses SiC in its automotive electronic control products and has invested in silicon carbide substrate, device design and wafer manufacturing.
KSEC Launches All-in-One SiC Power Electronics Components to Combat 800V High Voltage. The company is a leading enterprise in the field of automotive safety and electronics, with business covering intelligent cockpit, intelligent driving, new energy management and automotive safety systems. Under the trend of high-voltage fast-charging technology, Juniper has mass-produced multifunctional DC/DC converters, charging booster modules, OBCs and other power components and power supply components for the 800V high-voltage platform, as well as three-in-one integrated products of these components. The use of SiC power devices in the three-in-one integrated products will reduce the energy loss of the products themselves, allowing more energy to be used for power output, which in turn will improve vehicle drivability and range. The company's 800V high-voltage platform "ultra-fast charging" technology has been mass-produced in the European market. 3.4 Systematic upgrading of vehicle safety performance under high-voltage fast-charging architecture 3.4.1, The quantity and quality of high-voltage connectors are upgraded along with the safety performance index. Architecture change under high-voltage fast charging: quantity and quality of high-voltage connectors have been improved The quantity and quality of high-voltage connectors have been improved accordingly, and the quantity improvement is reflected in the newly added DC/DC converter and fast-charging piles, and the quality improvement is reflected in the fact that 800V needs to satisfy the corresponding thermal management and EMC requirements compared with 400V. High-voltage connectors, compared with low-voltage connectors, are an incremental part of new-energy vehicles for fuel vehicles, while low-voltage connectors are still retained for low-voltage circuits. High-voltage connectors are mainly used in the high-voltage high-current circuits of new energy vehicles, where the power from the battery pack is transmitted to the various components of the vehicle system, such as motor controllers, DC/DC converters, OBCs and other components through wires and cables. High-speed connectors are mainly used for information transmission inside the vehicle. New energy vehicles emphasize more on electrical equipment, and the number of high-speed connectors increases due to the increase of sensors and entertainment electronics. The increase of connectors from 400V to 800V is mainly reflected in high voltage connectors. Fast charging piles become the future technical difficulties of high-voltage connectors, the increase is obvious. High-voltage connector inside the car body in the next few years, with the internal structure of the car to the integrated direction of development and meet the requirements of high-voltage connector mass production, high-voltage interfaces inside the car tend to be interchangeable, the use of enhancement of bottleneck or even decline in the value of a single car has a downward trend. With the fast charging pile power increase, enterprises accelerate the layout construction, for fast charging pile internal to external charging gun interface, then to the battery side of the line, high-voltage connector has a larger technical variables, the amount of incremental obvious. High-voltage connector is compatible with liquid cooling circuit from charging pile end to battery board end has become a trend, material and design need to be upgraded. There are two main types of charging pile cooling on the market: liquid cooling and air cooling. With the increase of fast charging power, the performance requirements of fast charging piles for heat dissipation have increased. Liquid cooling has advantages over air cooling in many aspects, and the cables are relatively thinner, which can reduce the weight of cables by 40% compared with air cooling. At present, among the three leading supercharging brands in China, namely Tesla, Xiaopeng and Azera, only Tesla has applied liquid-cooled supercharging technology for charging power up to 250kW, and liquid-cooled supercharging is still in the early stage of development, with great potential for future development. Amplefoam North America's active liquid-cooled charging sockets allow the cooling circuit to be integrated into the body cooling circuit, and the high-voltage connector needs to be compatible with the liquid-cooled circuit from the pile end to the battery end. According to Cpcworldwide, high voltage connectors for liquid cooling solutions need to have the following characteristics: 1) Meet or exceed fluid compatibility, flow, pressure and temperature performance requirements. 2) Withstand suitable environmental operating conditions. 2) Withstand applicable environmental operating conditions, e.g. connectors used with vehicle batteries, over a wide range of temperatures, humidity, dirt/dust and vibration. 3) Avoid leakage - A robust seal design must be able to withstand installation and service stresses (lateral loads, bending forces, tensile forces) without compromising the seal, exposing expensive and critical components to fluids. Tesla Solution: The Model Y switched the high-voltage connector on the fast-charging end of the car from a nylon plastic material to an aluminum alloy, and the plug-in connection was replaced with a cylindrical bolt-on connection for better compatibility with liquid-cooled charging guns. The metal material is more costly, but it conducts heat better and can carry higher short-term currents, has better structural strength, and is more convenient for shielding and grounding; the bolt design increases the contact area and conducts heat better. Overall, it is favorable for the extension and upgrading of the liquid-cooled charging structure at the vehicle end connector. 3.4.2, isolation chip, three electric components common voltage insulation guarantee Architecture changes under high-voltage fast charging: digital isolation chip as the mainstream of new energy vehicle isolator, with the automotive platform voltage increase, the complexity of strong and weak circuit, electrical system integration, the number of digital isolation chip, performance and integration have a greater room for improvement. The role and classification of digital isolation chips: Isolation chips, also called isolators, can convert input signals to output and have the function of electrical isolation of input and output terminals. The strong and weak circuits involved in the electrical system of new energy vehicles are already complex, and with the high-voltage automotive platform, the circuits between 800V/400V/12V/48V are further complicated, which requires higher safety. Electrical isolation can prevent the current from flowing from strong circuits to weak circuits and causing equipment damage, and also block common mode, surge and other signal interference, so that the signal propagation is more reliable and safe. Digital isolation chip is a kind of technology route compared with optocoupler isolation chip, which has become the mainstream of isolation chip for new energy vehicles. Compared with traditional optocoupler, digital isolation chip is smaller in size, faster in speed, lower in power consumption, wider in temperature range, higher in reliability and longer in life. Digital isolation chip is divided into magnetic coupling and capacitive coupling, magnetic coupling is generally based on transformer, capacitive coupling is based on capacitance. Digital isolation chips are used in combination with different components in different high wattage power electronic devices in EVs, including on-board chargers (OBCs), battery management systems (BMSs), DC/DC converters, motor control drive inverters, CAN/LIN bus communication, and charging piles, etc., to realize isolated interfaces (digital isolators plus interface chips), isolated sampling (digital isolators plus operational amplifiers), and isolated driving (digital isolators plus operational amplifiers). It realizes the functions of isolated interface (digital isolator plus interface chip), isolated sampling (digital isolator plus operational amplifier), and isolated drive (digital isolator plus driver chip).
The number of isolation chips applicable to different power devices in EVs is on the rise. Upgrading from 400V to 800V increases the number of strong and weak circuits at different levels inside the EV, and considering the new DC/DC converter (400V to 800V) and the increase in the number of high-power charging piles, the number of digital isolation chips obviously tends to increase. The upgrading of power equipment itself will also drive the number of isolation chips used to rise, for example, in OBC and DC/DC, the replacement of IGBT by SiC has led to an increase in the number of isolated drivers. The isolation technology requirements for digital isolation chips increase with the power of the power devices. The high voltage and noise environments in drive systems require robust, high-performance current isolation to ensure safe and reliable operation. As electric vehicle subsystems increase in power and decrease in size, power density increases and thermal and electrical noise conditions become more demanding. Compared to traditional optocoupler solutions, digital isolation chips have significant advantages under high voltage conditions. When the voltage goes up to 600-800V or even above 1000V, the isolation chip needs to be more able to withstand the high voltage or it will easily leak. Based on the requirements of automobile safety, the performance of digital isolation chips needs to be improved with the increase of platform voltage. Among the digital isolation chips, the isolation driver is the most difficult to develop, and it needs to be developed in close cooperation with IGBT manufacturers. When it comes to high-voltage scenarios, IGBTs are upgraded to SiC, and the isolation driver needs to be developed and upgraded as well. Therefore, isolation chip vendors need to have a close cooperation relationship with IGBT vendors or have their own IGBT R&D capability. There is a trend toward integration of digital isolation chips with different functions. The development trend of the electrical subsystem inside the electric vehicle is higher integration, simpler structure, smaller volume and higher power density, so in addition to the high-voltage performance of the isolation chip needs to be upgraded in line with the system, the integration is also a major development trend of the isolation chip products, and the isolation chip that integrates the functions of interface, driver, sampling, sensing, etc., has a more competitive advantage. 3.4.3 Film Capacitors Replace Electrolytic Capacitors, Increasing Demand Architecture change under high-voltage fast charging: film capacitors replace electrolytic capacitors The demand and performance of film capacitors increase under high-voltage architecture. Capacitors play the roles of energy storage, tuning, aluminum foil, coupling, rectification and DC voltage isolation in electronic circuits, etc. Film capacitors are capacitors using plastic film as dielectric, which have the advantages of nonpolarity, high-voltage resistance, small dielectric loss and long service life compared with other capacitors, and have become one of the important components in new energy vehicles. Film capacitors in inverters are mainly used in high-voltage circuits for EMI and DC-Link, while aluminum electrolytic capacitors in inverters are mainly used in low-voltage circuits; film capacitors in OBCs and DC/DC converters are mainly used for EMI and DCLink. For example, when an inverter converts DC power to AC power, the DC input voltage to the inverter rises sharply, and film capacitors with the DC-Link function are needed as a connection to reduce the voltage overshoot and transient over-voltage effects on the circuit. 3.4.4. High Voltage DC Relays with Smart Fuses Provide Safe Redundancy Architecture change under high-voltage fast charging: relays and fuses increase the amount of value per vehicle HVDC relays differentiate between managing different high voltage circuits, increasing demand and performance. High-voltage DC relays are the increment of relays in new energy vehicles compared to traditional vehicles. Relays play the roles of cutting off, turning on and switching circuits, etc. High-voltage DC relays are adapted to the electrical working conditions of new-energy vehicles by designing arc extinguishing devices, improving coils, contact materials and heat dissipation structures, and possessing such properties as high voltage resistance, strong current-carrying capacity, strong breaking capacity, resistance to shock currents, good heat dissipation, and resistance to strong electromagnetic interference. The current circuit of new energy vehicles under high-voltage fast charging is more complex, requiring multiple relays for differentiated management, and the accelerated layout of fast charging piles in the future will further drive the increase of its volume. 800V platform has higher voltage and power, and the arc effect is more severe compared to 400V platform, so the performance of high-voltage DC relays needs to be improved in many aspects, and the core technology to improve the performance is mainly in the contact material, encapsulation technology, arc extinguishing, heat dissipation, cavity layout and other aspects, The core technologies to improve the performance are mainly in contact materials, packaging technology, arc extinguishing, heat dissipation, cavity layout and other aspects. High voltage DC relays can be enhanced by improved packaging and use with smart fuses. Relay ceramic sealing is suitable for the main circuit and fast charging circuit of high-voltage platform models. Compared with other sealing methods, ceramic sealing for relays is characterized by high structural strength, good insulation, good sealing, strong arc extinguishing ability, aging resistance, safety and reliability, etc. However, ceramic sealing involves costly ceramic brazing, laser welding, automatic self-assembling equipments, etc., and the investment scale of the production line in the early stage is relatively high. Intelligent fuse Pyrofuse provides safety redundancy with relays, and its value tends to increase in the future. Pyrofuse, as a new technological trend firstly developed and applied by Tesla, mainly plays the role of switch in the electric circuit, and when there is a collision, short-circuit, or other safety faults, Pyrofuse can cut off the power supply in a very short time, reducing the probability of danger. It realizes a change from passive fuse protection to active protection. However, it is difficult to replace high-voltage DC relays in new energy vehicles due to user economics and lack of switching function; however, Pyrofuse reduces the need for high-performance high-voltage DC relays, making the application of low-cost solutions possible.
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