differences between EV motor and ordinary motor

Electric vehicles are the development trend of the automotive industry. Everyone knows that the core of the principle is to replace the engine with a motor to achieve electric drive. But have you ever thought about whether the motor on an electric car is the same as a normal motor?

Electric vehicles are the development trend of the automotive industry. Everyone knows that the core of the principle is to replace the engine with a motor to achieve electric drive. But have you ever thought about whether the motor on an electric car is the same as a normal motor? The answer is definitely no, compared with the conventional use of induction motors, electric motor motors have a big difference in performance requirements and drive principles:

                                              pic 1: generator motor composition

 pic 2: electrical motor

1. The electric vehicle motor should have a large starting torque, good starting performance and good acceleration performance to meet the requirements of frequent starting and stopping, acceleration and deceleration or climbing of electric vehicles. Reflected in the motor test, it is required that the motor should have a short response time when the speed or torque is controlled. At the same time, when the external load changes stepwise, the motor itself should reflect quickly enough to adjust the output power and speed;

2. The constant power range of the motor motor should be designed to be wide to meet the torque output of the electric vehicle at high speed to ensure the highest speed that can be achieved by the car;

3. The electric vehicle motor should have a large range of speed regulation capability, have large torque at low speed, high power at high speed, and can adjust the driving speed and corresponding driving force of the electric vehicle at any time according to driving needs;

4, electric car motor should have good efficiency characteristics, in the wide range of speed / torque, to obtain the best efficiency, improve the continuous mileage after a charge, generally required in the typical driving cycle area, get 85% ~93% efficiency;

5. The outer dimensions of the electric vehicle motor are as small as possible, the quality is as light as possible, and the power density is optimized;

6. Electric motor motor should have good reliability, strong temperature and moisture resistance, long-term work in harsh environment, low noise during operation and convenient maintenance;

7. Combine with the motor controller to effectively recover the energy generated by the brake.

Create efficient new energy vehicle drive motors

Based on the in-depth exploration and long-term accumulation of the motor and electric vehicle industry, Zhiyuan Electronics successfully integrated special test items for new energy vehicles on the MPT series motor test system - MAP map and regenerative energy feedback test for the majority of electric vehicle motor designers. Provide excellent test solutions.

1.1.1 MAP map

According to GB/T 18488-2015 test standards for drive motor systems for electric vehicles, MAP map testing is required for new energy vehicle drive motors to obtain the efficiency characteristics and high-efficiency zone distribution of the motor. The actual test results of the MAP map are as follows:

In the figure, the horizontal axis is the rotational speed, the vertical axis is the torque, and the color indicates the efficiency. It represents the distribution of the efficiency characteristics of the motor under different working areas (rotational speed, torque), and the orange-red part is the high-efficiency area of the motor. . The wider the distribution of high-efficiency zones, the more power-saving the motor operates under various operating conditions.

The MPT motor test system has built-in MAP automatic test function, which can automatically control the load and the motor under test to load the corresponding working conditions according to the pre-set loading conditions of the user, and obtain the efficiency under different working conditions, and finally integrate the massive test data into one. The MAP map intuitively analyzes the efficiency characteristics and efficient area distribution of the motor for the user.

1.1.2 Regenerative energy feedback test

According to GB/T 18488-2015 test standard for drive motor systems for electric vehicles, it is also necessary to carry out regenerative energy feedback test for new energy vehicle drive motors. The purpose of this test is to consider whether the drive motor can normally realize the feedback of electric energy when braking, that is, when it is running in the generator state, and at the same time evaluate the real energy consumption of the motor.

For the regenerative energy feedback test of the drive motor, the remote motor MPT motor test system can flexibly utilize the integral function of the built-in MDA motor and the drive analyzer to integrate the input of the motor controller in real time to accurately capture the feedback of the motor during braking. Energy value.

At the same time, for the DC charge and discharge characteristics between the motor controller and the power battery, Zhiyuan motor specially designed the charge and discharge integral function, which can real-time integrate the sampling rate of the electrical signal at the input end of the motor controller, even if the motor is fast in the motor state and generator state. Switching between them can also capture the energy transfer between the motor and the power battery for a period of time.