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Electric vehicle system cost, size halved? TI integrated powertrain solutions do it

Posted by: Sipxtech 2022-09-15 Comments Off on Electric vehicle system cost, size halved? TI integrated powertrain solutions do it

With the rapid development of electric vehicle-related technologies and the continuous advancement of policies by governments around the world, more and more car consumers have turned to electric vehicles, especially in China. Relevant data shows that from 2015 to 2020, the overall sales of new energy vehicles have been rising steadily, and the sales of electric vehicles in the Chinese market has reached a record high (1.36 million units) in 2020, which is already the production and sales volume of new energy vehicles in my country. No. 1 in the world for 6 consecutive years. With the announcement of the index configuration results of the first phase of new energy passenger cars after the implementation of the Beijing Lottery New Deal on May 26, it is bound to stimulate a new round of car buying fever.

However, it is undeniable that consumers still have concerns about purchasing electric vehicles, the most prominent of which are mileage anxiety and price issues, which hinder the further popularization of new energy vehicles. The average production cost of an electric vehicle is reported to be $12,000 higher than that of a conventional internal combustion engine vehicle. According to some data, from the perspective of manufacturing cost, for a fuel vehicle, the cost of the engine + gearbox accounts for about 1/5 of the total vehicle cost; while the electric vehicle of the same model, the three-electric system (battery, motor, electric Control) accounts for half of the cost of the whole vehicle, and nearly 80% of this half is occupied by the power battery. Even with various subsidies, the price of the same electric car is now 50,000-100,000 higher than that of a gasoline car.

While battery technology continues to improve, other fields are also looking for breakthroughs to further reduce costs, and powertrain is the key. Recently, Texas Instruments (TI) released a powertrain integration solution that can cut system design costs in half, while effectively improving power density, efficiency and reliability, and making electric vehicles more affordable for more people.

Electric vehicle system cost, size halved? TI integrated powertrain solutions do it

Integrated powertrain cuts size and cost in half

“TI’s products and technical support can help customers fully realize the integration of powertrain system solutions. We expect that the integrated solutions can help reduce the size and cost of the entire system by half.” Field Technical Application Manager, Automotive Business Unit, Texas Instruments China Zhou Dongbao said.

How to achieve the halving? Zhou Dongbao pointed out that there are four aspects:

·All-in-one integrated solution for the electric drive system reduces the number of connectors by sharing the coupling of the housing and the cooling system;

·Through further sharing of control circuits and shared power circuits, the volume, weight and cost of the electric drive system are effectively reduced, while the power density of the electric drive system is improved;

·Better lightweighting helps to extend the cruising range of electric vehicles;

·By optimizing the thermal performance of the system as a whole, the reliability of the system is guaranteed.

At the same time, TI has noticed that functional safety is a very important design indicator in electric drive systems, and TI’s integrated solutions also help simplify the development and certification of functional safety systems.

Traditional powertrains include motor controllers, high-voltage power distribution units, DC/DC, on-board chargers, power management systems (BMS), and more. According to the number of different integrated modules, it can be divided into a two-in-one solution, a three-in-one solution, and a five-in-one solution. According to the difficulty of integration, it can be divided into basic mechanical level integration (physical integration), and more complex control logic and power level integration. “By using TI’s solutions, customers can move from a distributed power architecture to a single power domain controller solution. The complexity of the overall system increases as the level of integration increases, and the benefit to the customer increases. The higher the future, the more challenges will come at the same time.” Zhou Dongbao said, “For design challenges, TI will assist customers to solve them together.”

Electric vehicle system cost, size halved? TI integrated powertrain solutions do it

TI provides a three-in-one solution of motor controller, on-board charger and DC/DC, which greatly optimizes the architecture of the entire system and reduces the weight and volume of the entire drive cost by sharing part of the control circuit.

98% Efficiency and Ultra High Power Density

As a world-leading semiconductor company with a long history, TI has a rich and diverse product portfolio. Zhou Dongbao introduced the competitive advantages of TI’s powertrain solutions by taking the combination of several TI star products: C2000 microcontroller, the latest GaN FET, isolation driver UCC5870, and temperature sensor TMP126 as examples.

The microcontroller C2000 series can provide a processing power of up to 925MIPS. At the same time, combined with a flexibly configurable high-precision PWM module, it can be easily adapted to various complex power supply topologies and higher-order control algorithms, thus realizing the entire system. high efficiency.

TI’s latest integrated driver GaN FETs can operate at switching frequencies up to 2.2MHz while maintaining very low switching losses. In addition, combined with TI’s custom-developed low parasitic inductance enhanced heat dissipation chip package, it can achieve twice the power density improvement and reduce magnetic components by 59%.

The isolated driver UCC5870 series can provide a peak current drive capability of up to 15A, without the need for an external power amplifier circuit, and can also ensure that the entire switch tube can be turned on and off very efficiently, thereby achieving higher efficiency.

The temperature sensor TMP126 can operate at an ambient temperature of 150°C with a sampling accuracy of up to ±0.3°C. Higher temperature sensor accuracy can help customers design the entire system with a smaller design margin. At the same time, the accuracy of the system dynamic temperature compensation can be higher, which helps to maximize the system efficiency.

system level reliability

The reliability of electric vehicles is a very important aspect of design, and TI powertrain solutions can also bring reliability and performance improvements.

C2000 series microcontrollers have built-in rich analog function modules, such as DC, DAC, and comparators, which can achieve a response time as low as 30ns, and respond to diagnostic protection and faults. Since it is completely controlled by pure hardware and does not require the participation of the CPU module, the reliability of the system can be further improved.

The built-in digital temperature sampling function of GaN FET devices can provide real-time temperature information, enabling more flexible thermal management of dynamic systems. TI integrates commonly used protection functions such as overcurrent, short circuit, overtemperature and undervoltage into the GaN switch tube, without the need for additional discrete circuits. At the same time, the built-in short-circuit and over-current protection circuits can respond in as little as 100ns, which also improves the reliability of the system.

The isolated driver UCC5870 series can perform short-circuit protection within 200ns, and at the same time achieve the industry-leading common mode rejection ratio (CMTI) (>150V/ns), which means that the chip can maintain reliable communication in harsher noise environments, ensuring that The switch tube can be correctly driven to perform corresponding actions, thereby achieving higher system-level reliability.

The temperature sensor TMP126 maintains very high accuracy over the full temperature range (-40 to +175°C). Compared with discrete devices, the temperature drift is almost negligible. At the same time, the built-in cyclic redundancy check function of the digital interface can also ensure reliable communication in high noise electromagnetic environment.

System cost and size cut in half

The C2000 has a high immediate instruction set that can significantly reduce the number of cycles required for complex calculations. Combined with the high switching frequency and low switching loss characteristics of GaN and SiC devices, the size of magnetic components can be significantly reduced and the efficiency of the entire system can be increased, thereby also increasing the power density of the entire system.

According to Zhou Dongbao, the use of gallium nitride devices is expected to reduce the size of on-board chargers and DC/DCs by 50% compared to existing silicon and silicon carbide-based MOSET solutions.

The isolated driver UCC5870 series can meet the needs of most MOSET and IGBT drivers due to its peak current capability of up to 15A. At the same time, the built-in six-channel isolated sampling ADC can be used for temperature and voltage acquisition, reducing the cost of additional discrete isolated ADCs. The UCC5870 chip has built-in more than 50 functional safety-related mechanisms, which can significantly reduce the BOM cost in functional safety-related applications.

The high-precision temperature sensor TMP126 can help customers further reduce costs by optimizing the design of the entire cooling system.

The above combination is one of many TI powertrain solutions. You can find a wealth of reference design resources on TI’s official website, and these reference designs are not just a simple combination of individual chips. “When we made these reference designs, we took into account the overall performance requirements of the system. We will take into account the overall EMI performance, including how to choose a topology and how to choose a control strategy. The whole set of solutions will be considered, so that the overall product will be The performance meets the requirements.” said Cao Weijie, TÜV SÜD certified functional safety engineer, a member of the Texas Instruments EV/HEV SEM team.

Simplified Security Authentication

According to Zhou Dongbao, TI is helping customers simplify the development and certification of functional safety system designs in two ways:

One is to provide products that meet functional safety standards. For example, the isolation driver UCC5870 is a product developed according to TI’s functional safety product development process certified by TÜV SÜD, and can provide complete functional safety related documents, such as FMEDA, functional safety manual, FIT value, etc. For most commonly used signal chain products, such as simple power supply and signal chain products, TI can provide technical documents such as the FIT value of the entire device functional safety and the distribution of failure modes to help customers design functional safety.

Second, in order to speed up customer development time, TI worked with TÜV SÜD to develop an upgraded reference design TIDM-02009 that can achieve ASIL D functional level integrated traction drives and DC/DC converters, which uses TI’s latest C2000 Series MCU and UCC5870 isolated driver, can achieve up to 20 000rpm speed, and 2 MHz switching frequency.

The entire powertrain will move towards integration

As many manufacturers enter the car, the way semiconductor manufacturers work has also changed. Cao Weijie said that TI is now more and more directly cooperating with OEMs and Tier 1s to provide them with system solutions to meet their requirements, rather than simply providing devices as a chip manufacturer. Therefore, TI starts more from the perspective of system solutions and provides a complete set of solutions to meet the needs.

Shenzhen Wemax New Energy is a Tier 1 company with more than 50 customers, including traditional OEMs and new car manufacturers. At the same time, it is maintaining in-depth cooperation with TI. “In the past few years, we and TI have achieved great results in continuous product innovation, forward-looking high-performance product applications, and professional technical cooperation and exchanges.” Vice President and Vice President of Shenzhen Wemax New Energy Co., Ltd. Han Yongjie, general manager of the Shanghai subsidiary, introduced.

The current integration scheme mainly consists of three parts: OBC, DC/DC and PDU. The future trend will be that the entire power system will tend to be integrated. “In terms of future development, in fact, further integration is required. Wemax has done a lot of work in this area, and we are also in-depth cooperation with TI in applications, especially on C2000 and UCC5870 driver chip products. .” Han Yongjie said.

The cost and size reduction brought by the powertrain is of great benefit to both the OEM and the end customer, which makes the trend of integration inevitable, although the integration of BMS has not yet been seen in the market. , With the development of the market and the promotion of technology, future integration may include BMS systems, electric vehicle power management ICs will be highly integrated, and the cost gap with fuel vehicles will continue to narrow.