The hot after-sales cost of new energy vehicles will be reduced

According to the data of yichenglian, from January to April this year,New energy vehicle The production and sales of more than 700000 vehicles reached 750000 and 732000 respectively, and the sales record of the current month has been updated for 10 consecutive months. Cui Dongshu, Secretary General of the national passenger car market information Federation, predicts that the sales volume of new energy passenger cars will exceed 2.2 million this year,New energy vehicle The overall market reached 2.5 million.

Although the sales heat is high, many consumers still have a lot of concerns about buying electric vehicles. For example, the safety of the battery, the convenience of charging, the continuous distance and the cost are higher than those of the fuel vehicle. These problems more or less hinder New energy vehicle Further popularization of.

According to McKinsey's report, the average production cost of electric vehicles is $12000 higher than that of traditional fuel vehicles. In order to narrow the cost gap, improve efficiency, reliability and extend the duration, it is a great challenge for automotive design engineers. However, the electric vehicle powertrain integration solution may be a good choice.

Powertrain integration reduces system size and cost by 50%

At first, it was thought that the price difference between electric vehicles and fuel vehicles was caused by batteries. Indeed, the cost of batteries accounts for a large proportion in electric vehicles, but with the progress of technology and the efforts of battery manufacturers, the cost of batteries is expected to be greatly reduced in the future. But in fact, in addition to batteries, power components, namely power electronic components, are also one of the reasons for the cost difference between electric vehicles and fuel vehicles.

Zhou Dongbao, field technology application manager of ti China automotive business department.

For example, according to the number of integration modules, there are two in one, three in one and five in one integration solutions. According to the difficulty of integration, power integration can also be divided into basic mechanical level integration, that is, physical integration, and more complex control logic and power level integration.

According to Zhou Dongbao, by using TI's solution, customers can realize the change from distributed power structure to controller scheme in a single power field. The complexity of the whole system also increases with the increase of integration level, and the revenue to customers is higher and higher. However, he also admits that the higher the integration degree, the more challenges he faces.

Zhou Dongbao further pointed out that the integrated scheme can help customers reduce the size and cost of the whole system from the following aspects.

First, the multi combination integrated solution of the electric drive system reduces the number of connectors by sharing the coupling and cooling system of the housing

Secondly, by further sharing the control circuit and power circuit, the volume, weight and cost of the electric drive system can be effectively reduced, and the power density of the electric drive system can be improved

Third, the better realization of lightweight will help to extend the continuous distance of electric vehicles

Fourthly, the reliability of the system is guaranteed by optimizing the thermal performance of the system as a whole. At the same time, functional safety is a very important design index in the current electric drive system, and the Ti integrated solution also helps to simplify the development and certification of functional safety system.

How to realize the integration scheme of Ti powertrain?

From the three in one solution of Ti motor controller, on-board charger (OBC) and DC / DC, it can be seen that the three in one solution can greatly optimize the structure of the whole system, and reduce the weight and volume of the whole drive system through the control circuit of the shared part.

According to Zhou Dongbao, TI's three in one power integrated solution uses C2000 series microcontroller, integrated driver Gan field effect transistor, isolation driver ucc5870, temperature sensor tmp126 and other TI products.

He deeply analyzed that firstly, C2000 series microcontroller is adopted to provide processing capacity up to 925mips. Combined with its flexible high-precision PWM module, it can easily adapt to various complex power supply, develop simple and higher control algorithms, and realize higher efficiency of the whole system. Built in very rich simulation function modules, such as built-in rich simulation function modules. These modules can realize the response time as low as 30ns and respond to some diagnostic protection and faults. The control response is purely hardware control, does not need the participation of CPU module, and can further improve the reliability of the system.

Second, using the integrated driven Gan field effect transistor, the gate capacitance and output capacitance of the switch can be lower than that of the silicon tube. At the same time, the Gan device has no reverse recovery problem of the traditional MOSFET parasitic diode, so it can work at a switching frequency of up to 2.2MHz and maintain very low switching loss. The enhanced heat dissipation chip package with low parasitic inductance customized by Ti can increase the power density by 2 times and reduce 59% of magnetic components. Gallium nitride power equipment has built-in digital temperature sample function to provide real-time temperature information, which can more flexibly realize the thermal management of dynamic system. Ti also integrates some common protection functions such as over-current, short circuit, over temperature and insufficient pressure into gallium nitride switches. Customers do not need to add vertical circuits to realize these functions. At the same time, the built-in short-circuit and overcurrent protection circuit can respond in a time as low as 100ns, so as to improve the reliability of the system.

Third, the isolated drive ucc5870 series can provide a driving force of up to 15A peak current, which also means that customers do not need to add additional power amplification circuits, and can also ensure that the switch tube can be switched very effectively, so as to achieve higher efficiency. Ucc5870 can carry out short-circuit protection in 200ns, and the common mode rejection ratio reaches 150V / NS, which is a very high level in the industry. Higher common mode rejection ratio means that Ti chip can maintain reliable communication in worse noise environment, and can correctly drive the switch tube to act accordingly to achieve higher system level reliability.

Fourth, the temperature sensor tmp126 works under the ambient temperature in the full temperature range (- 40 ℃ ~ + 175 ℃), and the sampling accuracy reaches plus or minus 0.3 degrees. The significance of such high accuracy to the system is that the higher the accuracy of the temperature sensor, it can help customers leave less design margin when designing the whole system. At the same time, in the dynamic temperature compensation of the system, the accuracy is higher, which also helps to maximize the efficiency of the system. In addition, the built-in cyclic redundancy check function of its digital interface can also ensure reliable communication in the noisy electromagnetic environment.

Zhou Dongbao specially introduced Ti to help customers simplify the development and certification of functional safety system design

First, Ti can provide products that meet functional safety standards. For example, the isolation drive ucc5870 is a product developed through the functional safety product development process certified by tvsd. For this product, fmeda, functional safety manual, fit value and other very complete functional safety documents can be provided. Zhou Dongbao said. For most commonly used signal chain products, such as simple power supply and signal chain products, Ti can provide technical documents such as fit value of overall functional safety of equipment and distribution of fault modes to help customers design functional safety.

Secondly, in order to speed up the development time of customers' products, Ti cooperated with ttvstad to develop the upgrading scheme of asild integrated traction drive and DC / DC converter with higher functional safety level. Tidm-02009 related data, design documents and other data can also be found on TI's home page. The reference design uses ti's latest C2000 Series MCU and ucc5870 isolation driver, which can realize 20000 speed and 2MHz switching frequency.

Finally, Zhou Dongbao summarized the advantages of Ti powertrain system integration solution: 1. The integration solution has high power density and the efficiency of the whole system can reach 98%. 2. Ti can improve the reliability of the whole circuit by using TI product technology to optimize the thermal performance of customers and design diagnosis, protection and other circuits. 3. By using TI products, the cost of the whole system can be greatly reduced, and fewer equipment, smaller solutions and sizes can be used. 4. Ti provides a variety of solutions to simplify customer functional safety certification, such as asild compliance certification.