[Introduction]Driven by the trend of electrification, the new energy vehicle industry has stepped up, and the complete withdrawal of fuel vehicles has become an irreversible trend. According to EV Volumes data, the global sales of new energy vehicles in 2021 will be 6.75 million, a year-on-year increase of 108%, and the penetration rate will exceed 8.3%. Obviously, with the “three-electric system” of new energy vehicles, battery, electric drive, Electronic control and other technologies are gradually improved in innovation and upgrading, the market penetration rate of new energy vehicles will be greatly increased, and the “policy-driven” to “market-driven” will be gradually completed. Transition.

Figure 1: 2012-2021 Global New Energy Vehicle Market Trend

(Image source: EV Volumes)

The market potential of new energy vehicles is broad, but for a long time, problems such as short cruising range, long charging time, and battery safety still hinder the development of new energy vehicles. To this end, mainstream car companies are actively seeking ways to break through the situation. Increasing battery capacity, improving energy replenishment efficiency, and shortening charging time have gradually become the entry point to break through the bottleneck.

In theory, with the same charge, the higher the charging power, the faster the charging speed. Therefore, increasing the charging power has become one of the ways to effectively resolve the range anxiety of electric vehicles. For new energy vehicles, upgrading high-power fast charging will drive the whole body, which will inevitably lead to the replacement and upgrading of semiconductor components.

Under the high-voltage and high-current architecture, whether it is the vehicle system or the charging pile, battery, electric drive, PTC auxiliary, air conditioning system, etc. need to be re-adapted, the charging gun, wiring harness, contactor and fuse also need to be based on the high-voltage architecture. to adjust. Power semiconductors need to have higher withstand voltage levels and switching losses, and magnetic components are also developing in the direction of high power, small size, and modularity. This article will use magnetic components and protection devices as examples to illustrate how high-power super-fast charging affects the selection of components for electric vehicle charging systems.

High-power fast charging drives a comprehensive upgrade of vehicle components

The industry generally believes that high-power fast charging requires a charging current greater than 2C and a charging time less than 30 minutes, and its implementation is nothing more than increasing the current or increasing the voltage. The low-voltage and high-current mode will increase the heat generation of the electrical system, and put forward higher requirements on heat dissipation technology, wiring harness standards and space. It is the limit to increase to 600A, which is difficult to meet the needs of faster charging. The high-voltage technical route can reduce heat loss, reduce vehicle mass, optimize power structure, and improve safety performance, thus becoming the best choice for increasing the charging rate.

Through high-power fast charging, the heat generated by charging will be greatly increased, which puts forward higher requirements for components such as voltage withstand level, insulation performance, switching loss, and high temperature resistance. For component manufacturers, challenges also arise. Taking magnetic components as an example, component manufacturers not only need to develop higher-performance high-frequency magnetic materials to improve the performance parameters of components, but also need to improve the production process to meet complex and changing process requirements, while continuously reducing the size of components.

In addition, safety performance is a major pain point for high-power fast charging. Ensuring the safety and reliability of high-voltage circuit systems should start from component manufacturers. In addition to improving the withstand voltage level and insulation performance of components, component manufacturers also need to optimize protection devices such as fuses to improve their breaking and arc extinguishing capabilities.

Domestically, in order to shorten the charging time, improve the efficiency of energy replenishment, and promote the full popularization of new energy vehicles, mainstream companies such as BYD, Xiaopeng, Geely, and Huawei have entered the market and launched high-voltage platform solutions for high-power fast charging applications. Speed ​​up. It is estimated that by 2026, the sales volume of high-voltage platforms above 800V will exceed 5.8 million, accounting for more than 50% of electric vehicles, and the stock of high-voltage platforms above 800V will reach about 13 million.

In addition, the national standard for electric vehicle conductive charging connection devices has also been officially revised at the beginning of this year. The revision of the super charging technology standard means that high-power fast charging is officially incorporated into the national standard system, which further promotes the domestic electric vehicle industry to move towards high-power fast charging. Under this standard, the charging voltage can reach up to 1,000V (1,500V), the maximum current can reach 600A, the charging power can be increased up to 900kW, and the charging time can be greatly shortened to less than 10 minutes.

Power conversion systems face a comprehensive upgrade

As new energy vehicles enter the era of high-power fast charging, the charging voltage has increased to 800V, or even exceeded 1,000V, which has put forward higher requirements for the charging module conversion device. As an important part of the electric vehicle power conversion system, devices such as rectifiers, film capacitors, and magnetic components occupy a large proportion of the space in the car charging module, and their performance is related to the quality of the entire conversion module.

Mouser’s ultrafast rectifier, the VS-E5PX6012L-N3, is an X-Series 1,200V fifth-generation FRED Pt® rectifier from Vishay. Judging from its parameters, the VS-E5PX6012L-N3 has a repetitive peak reverse voltage of up to 1,200V, and a maximum rating of 60A of average forward current. Under the condition of 100Hz sine wave and case temperature of 45℃, the forward single surge current can reach 420A, which has good anti-shock and overcurrent capability.

Figure 2: VS-E5PX6012L-N3

(Image source: Vishay)

When the forward current is 60A and the junction temperature is 125℃, the maximum forward voltage drop of VS-E5PX6012L-N3 is about 2.1V, and the conduction loss is low; when the junction temperature is 25℃, when the reverse voltage is At 1,200V, this rectifier features a reverse current of only 50µA maximum, low forward voltage drop and low reverse current.

Figure 3: Forward voltage drop characteristics and typical values ​​of reverse current and reverse voltage

(Image source: Vishay)

When the forward current is 60A and the reverse voltage is 800V, the reverse recovery time of VS-E5PX6012L-N3 is about 90ns, and the switching characteristics are good; the peak recovery current is 32A, and the reverse recovery charge is 1570nC, which greatly reduces the conduction loss of the device. and turn-off losses.

Overall, the VS-E5PX6012L-N3 rectifier has the unique advantages of low conduction loss and switching loss, making it the best choice for soft switching/resonant high frequency converters. The device is designed to improve PFC efficiency and output rectification stages for EV/HEV battery charging stations, boost stages for solar inverters, and UPS applications, and can be perfectly matched to MOSFETs or high-speed IGBTs.

Figure 4: VS-E5PX6012L-N3 dynamic characteristics

(Image source: Vishay)

At the same time, VS-E5PX6012L-N3 adopts TO-247AD 2L (single diode) package, which has a wide operating temperature range, good high temperature characteristics, and higher reliability. It can adapt to different working environments in the temperature range of -55℃ to +175℃ .

Rectifier losses are reduced by 10% compared to comparable silicon solutions. The rectifier significantly improves system efficiency and reduces conduction losses by 10%. For applications in the frequency range of 50kHz, the VS-E5PX6012L-N3 reduces switching losses and Qrr (reverse recovery charge) by more than 40% under the same forward voltage conditions, providing customers with a more cost-effective alternative.

The MKP339 X2 anti-jamming film capacitors, also from the manufacturer Vishay, have the manufacturer number BFC2339xxxxx on the Mouser Electronics website. MKP339 X2 series capacitors are MKP (metallized polypropylene film) radial potting capacitors, which have the advantages of low loss, small internal temperature rise, self-healing after breakdown, and good flame retardant performance.

Figure 5: MKP339 X2 Anti-jamming Film Capacitor

(Image source: Vishay)

Specifically, for example, the capacitor whose manufacturer number is BFC233926224 has a capacitance value of 0.22μF, a tolerance of ±20%, a lead spacing of 15mm, a rated AC voltage value of 310V, and a rated DC voltage value of 630V. In addition, the working temperature range of this capacitor is between -55°C and +110°C, and the capacitance value and dissipation factor can remain highly stable in a wide temperature range, with excellent high temperature resistance and high frequency insulation performance.

Overall, the lead spacing of the MKP339 X2 series capacitors covers the range from 7.5mm to 27.5mm and is AEC-Q200 compliant. In addition, the MKP339 X2 film capacitor has a capacitance range of 0.001μF to 4.7μF, which can meet the parameter requirements of most high-voltage, high-current and high-pulse-intensity circuits, and is suitable for standard cross-line X2 applications. Compared with other technologies, the MKP339 X2 film capacitor has a higher capacitance value, and the internal series structure can maintain the capacitance and prolong the service life.

Figure 6: Typical Circuit and Safety Capacitor Diagram of Film, Ceramic Chip and Multilayer EMI Suppression Capacitors

(Image source: Vishay)

In the high-power module application of new energy vehicles, integrated module products can also be used. In the field of electric transportation, Bel Power Solutions has very efficient on-board power conversion products for electric trucks, electric buses, electric passenger cars and hybrid electric vehicles. Provides solutions including DC-DC converters, on-board chargers and DC-AC inverters.

BEL’s 350DNC40-12-8G is an isolated DC/DC buck converter suitable for new energy gas. The outstanding advantages of 350DNC40-12-8G are high output power and high efficiency, the power of a single product is up to 4kW, and the output power of 4 combinations is up to 16kW. Converts HVDC voltage to LVDC voltage suitable for powering low voltage (12VDC/24VDC) accessories, combining high efficiency, high reliability, low output voltage noise, excellent dynamic response and other advantages, widely applicable to hybrid electric (HEV) vehicles and electric vehicles.

This converter can convert 240V-430V DC high voltage to 12V low voltage DC, and the maximum output current supports 278A. At the same time, the 350DNC40-12-8G is equipped with a CAN bus serial interface, which can adjust the average output voltage through software. The 350DNC40-12-8G waterproof grade is IP65 and IP67, and the input and output are completely electrically isolated, which can realize over-temperature, output over-voltage and over-current protection, and input and output reverse polarity protection, which can effectively reduce the suppression ripple and avoid electromagnetic interference, and improve the safety performance of the vehicle charging system.

On the premise of ensuring the reliability and stability of the system, the typical efficiency of 350DNC40-12-8G reaches 93%. By carrying the BCL25-700-8 on-board battery charger, it can effectively shorten the charging time of the vehicle system and improve the cruising range of the vehicle.

Figure 7: 350DNC40-12 Series Buck Converters

(Image source: Bel Power Solutions)

In addition, Bel Power Solutions also matched the 350DNC40-12-8G with the corresponding connector kit 350DNC40-CON-KIT-9G, and used the 350DNC40-CON-KIT-9G to provide the reliability and safety of the 350DNC40-12-8G. for better protection.

Build a complete high-voltage safety structure

For high-power fast charging, the working voltage is much higher than the safe voltage, and the discharge current is as high as tens of amps or even hundreds of amps. Once overload, short circuit or leakage occurs, it will cause heat to the vehicle system or components. damage, insulation damage, or even fire, explosion or personal injury. Therefore, how to ensure the safety and reliability of the power battery system and the high-voltage system, and how to optimize the safety circuit design of the high-voltage system has gradually become an urgent problem to be solved by the current mainstream car companies.

For high-voltage circuit systems, by configuring fuses/fuses, NTC thermistors and other devices in the loop, real-time temperature monitoring and control can be realized. Extinguish the arc, so as to ensure the safety of the vehicle system and personal safety.

Mouser’s fast-acting fuse, the 0ADAC0600-BE from Bel Fuse, is packaged in a compact 6.3mm x 32mm package with a slim profile and small size, helping to miniaturize vehicle safety systems.

Figure 8: Fast acting fuse 0ADAC0600-BE

(Image credit: Bel Fuse)

The rated voltage of 0ADAC0600-BE is 600VAC/DC, the rated current is 0.6A, and the breaking capacity is up to 10kA. It has a very fast response speed in the event of overload or short circuit, and can open the circuit within 0.001 to 0.01 seconds at 10 times the rated current. .

In addition, the fuse is also made of ceramic materials, which can quickly cut off the faulty subsystem when the current is overloaded, ensure the normal operation of the remaining subsystems, provide overcurrent safety protection for high-energy and high-power applications, and greatly reduce electrical The whole machine is paralyzed due to the failure.

Figure 9: Fuse Time Current Curve

(Image credit: Bel Fuse)

Overall, the fast breaking capability of the 0ADAC0600-BE fuse in high-voltage systems is very advantageous in the application of high-voltage fast charging of electric vehicles. Therefore, 0ADAC0600-BE fuses can provide stable and reliable safety protection functions in automotive DC/DC conversion modules, power inverters and other application fields.

Summarize

From the perspective of cost and technology, high-power and high-voltage fast charging is gradually becoming the standard for new energy vehicles. Many mainstream car companies have successively launched 800V high-voltage platform architectures and accelerated the evolution and upgrade to 1,000V or even higher voltage architectures. Under the trend of high-power fast charging, the semiconductor components configured in the vehicle system and charging piles need to be re-selected to meet the higher requirements of the high-voltage system for device withstand voltage level, high temperature resistance, insulation, low loss, etc. .

As the world’s leading distributor of electronic components, Mouser Electronics provides a wide variety of magnetic components, rectifiers, film capacitors, protection components and other device categories, which can meet all the component upgrade and replacement needs of high-power fast charging and help car companies use more The low total cost of ownership achieves a more secure, reliable, flexible and efficient vehicle architecture upgrade goal.

Source: Mouser Electronics