The important role of technological innovation in reducing the cost of motor controller
2017/12/20 17:05:59
An overview of the background
The performance of the motor drive system is directly determined by the performance of the motor drive system. It is one of the three key common technologies to support the electric vehicle technology system. In the requirements, with high performance, reliability, safety and low cost; in high performance, the performance of the system to ensure the vehicle power, increase vehicle mileage driven good motor; the reliability and safety aspects, directly affects the degree of connection by the usability and the user of the vehicle at low cost; the motor drive system, the cost will affect the process of industrialization of new energy vehicles.
Liu Jun, senior engineer of the Institute of electrical engineering, Chinese Academy of Sciences
Two, a brief discussion on the way to reduce the cost of technology innovation
1. cost targets for DOE electric drive system in the United States
2. cost composition of electric drive system
The main ways of reducing the controller cost include: (1) effectively improve the existing material utilization and localization rate (Si based IGBT and capacitance components); (2) the power control assembly and power train integration innovation; (3) the all SiC controller based on the third generation semiconductor technology.
3. improve the material utilization of Si based IGBT module
The innovative IGBT packaging technology improves the unit area current carrying capacity of the chip, while the chip work junction temperature (Tjop) increases from 125 degrees C to 175 C.
Plastic / double sided cooling package technology is one of the promising low cost solutions. Meanwhile, Tj online detection (chip integrated temperature sensor and loss / thermal resistance model calculation) is combined to reduce the design margin. In addition, the use of large and inexpensive plastic separation devices, such as Tesla, can effectively reduce the cost of modules (estimated above >30%).
4. improve the localization rate of Si based IGBT module
The advantages of IGBT international manufacturers are obvious, and the domestic development potential is huge. At present, the domestic IDM model and the IGBT complete industrial chain have been formed in China. In China, BYD as the representative of the manufacturers has accomplished the domestic application of IGBT in the high iron and new energy vehicles, new energy automotive / rail market demand to accelerate domestic alternative IGBT.
The electrical power device testing center of Chinese Academy of Sciences is currently the first specifically for high power semiconductor devices of the national CNAS certification laboratory, enterprises and research institutions to detect foreign service center has more than 30, can predict the lifetime of the IGBT module and actual conditions to provide. The demand for commissioning test of IGBT manufacturers in China is increasing, and the maturity of the products is rapidly improved.
5. improve the capacitance and the cooling capacity of the laminated busbar
The laminated busbar has electrical and mechanical connection, effective heat conduction, the bus is pressed on the plate by thermal insulation materials, can effectively improve the capacitor ripple current and reduce the size of copper.
Integrated innovation of 6. power control assembly and power assembly
The powertrain assembly scheme of motor plus controller + reducer (or gearbox); main drive + oil pump + air pump +DCDC+ high voltage distribution multifunction commercial vehicle power control assembly (PCU) plan can effectively reduce system cost.
7. third generation semiconductor SiC controller
A chip, a generation module, a generation system, SiC as the representative of the third generation semiconductor is high efficiency, high speed and high temperature, the use of advanced packaging technology can enhance the power density of Si controller several times (2020 domestic target is larger than 30kW/L, loading more than 1000 sets). SiC+ advanced packaging technology can effectively reduce the loss of the controller and increase the power density of the controller several times. The comprehensive cost of the scale system is advantageous.
With the rapid development of SiC chip, module and controller technology in China, the speed of industrial chain construction is speeding up, and the gap with international mature technology is narrowing.
