Introduction to electric control system of new energy motor

There is a huge space for improvement in the performance of new energy electric vehicles. We often pay the most attention to the battery. As a key component to determine the performance of electric vehicles, this paper talks in detail about the electric control of the motor.

First, the importance of electric control of new energy motor

As a substitute for traditional fuel vehicles, the main electrical system of new energy vehicles is the "three electricity" of electric powertrain system -- battery, motor and electronic control, which is extended on the basis of the "three small electricity" of traditional vehicles (air conditioning, steering and braking). Among them, the performance of motor and electronic control system, as an alternative to the traditional engine (transmission) function, directly determines the main performance indicators of electric vehicles such as climbing, acceleration and top speed.

At the same time, the new energy motor and electric control system are faced with relatively complex working conditions: they need to be able to frequently start and stop, acceleration and deceleration, require high torque at low speed/climbing, require low torque at high speed, and have a large speed change range; Hybrids also need to deal with special functions such as motor start-up, motor generation and braking energy feedback. In addition, the power consumption of the motor directly determines the range of the fixed battery capacity. Therefore, electric vehicle drive system has special requirements in terms of load requirements, technical performance and working environment:

First, the drive motor should have higher energy density, achieve lightweight, low cost, adapt to the limited interior space, at the same time should have the energy feedback ability, reduce the vehicle energy consumption;

Second, the driving motor has high-speed wide speed regulation and low-speed large torque to provide high starting speed, climbing performance and high-speed acceleration performance;

Third, the electronic control system should have high control precision, high dynamic response rate, and at the same time provide high safety and reliability.

As an important part of the new energy automobile industry chain, the technology and manufacturing level of the electric motor electronic control system directly affect the performance and cost of the vehicle. At present, the degree of autonomy in the field of motor and electronic control in China is still far behind that of battery. Some core components of electric control of motor, such as IGBT chips, still do not have complete independent production capacity. There are still few vehicle enterprises and parts enterprises with complete intellectual property rights of the system. With the gradual improvement of the domestic industrial chain of electric motor electronic control system, the localization rate of electric motor electronic control system is gradually improved, and the growth rate of electric motor electronic control market is expected to exceed the growth rate of new energy vehicle market.

Battery, motor, electric control in the application of new energy vehicles

In addition, with the promotion of lightweight vehicle body structure, the cost ratio of battery, motor and electronic control system in new energy vehicle is also gradually rising. According to the statistics of Argonne National Laboratory, the cost of new energy vehicle powertrain (motor, electronic control, transmission) accounts for 15.67%(sedan) and 13.69%(minivan) of the total vehicle cost, the proportion of the assembly is second only to the battery and BMS system. Driven by the policy of gradual decline of subsidies for new energy vehicles, the pressure of powertrain cost and weight reduction will be gradually transmitted upward to manufacturers of electric motors and electronic control products. Suppliers with advantages in technology and scale will take advantage in the process of cost reduction. Therefore, the electric motor control market still affects the trend of new energy vehicle market to a large extent.