Electric vehicle controller test solution
First, the introduction
The electric vehicle controller is the core control device used to control the start, run, advance and retreat, speed, stop and other electronic devices of the electric vehicle. It is like the brain of an electric vehicle and an important part of an electric vehicle. Electric vehicles currently include electric bicycles, electric two-wheeled motorcycles, electric tricycles, electric three-wheeled motorcycles, electric four-wheeled vehicles, battery vehicles, etc. Electric vehicle controllers also have different performance and characteristics due to different models. . The common electric vehicle controller is shown in Figure 1. For electric vehicle controllers, Itech Electronics has corresponding power and electronic loads to meet customer testing needs.
Second, the principle and structure
Electric vehicle controller, that is, DC brushless motor controller, motor drive and control system composed of controller, motor, rotary handle, brake lever, power assist sensor, etc.
Third, the test method
Itech is committed to providing test solutions for the new energy industry, with a variety of high performance products such as IT8800, IT6500 and IT6700H.
1, the battery part
At present, the main specifications of the battery box are 36V/12AH, 48V/12AH, 36V/14AH, 48V/14AH, 36V/17AH, 48V/17AH, 36V/20AH and 48V/20AH, etc. The IT6500 series wide range high power DC power supply can be selected. Or the IT6700H series wide-range power supply simulates the battery box output to power the controller and the back-end equipment.
The IT6500 series has a wide range of high-power DC power supplies in over 100 models, ranging from 800W to 30kW, and output ranges up to 1000V and 1200A. The IT6500C series, which has rich measurement functions and high-speed response, also provides high performance and stability. The output of the IT6500D series can be easily selected by the user. In addition, the IT6500C series also has CC&CV priority function, which can avoid current overshoot by selecting the response speed of the CC/CV loop and the voltage and current rise and fall speed.
2. Absorption of back electromotive force
When the motor is running, there is a wire that passes current, and the energized wire cuts the magnetic line to generate an electromotive force. Therefore, when the motor is running at the cutting magnetic line, an electromotive force is also generated. Judging by the right hand rule, the direction of this electromotive force is opposite to the voltage applied across the motor, so the electromotive force generated here is called the back electromotive force.
Calculation method: set the area of the coil to S, the angular velocity to w, and the magnetic induction coefficient to B, then the back electromotive force E=BSw. If the number of turns n is known, then E=nBSw.
Effect: The motor itself has a voltage. After the back electromotive force is generated, the equivalent voltage is smaller (the two are opposite in direction, so the phase is subtracted), so the motor will not be burned out.
In order to absorb the back electromotive force of the motor and increase the efficiency of the motor, we can increase the DC load at the front end to consume the back electromotive force generated by the DC brushless motor cutting the magnetic induction line. The IT8800 series high-performance DC electronic load can be selected to set the load to work in the CV constant voltage mode, and the voltage setting value is greater than the output voltage of the analog battery power supply to avoid consuming the power output from the power supply DC source.
IT8800 series power range 150W-55kW, voltage / current measurement speed up to 50kHz, resolution up to 0.1mV / 0.01mA, to meet customer high-precision testing needs; with constant voltage, constant current, constant resistance, constant power four Operating mode, perfect protection function, built-in RS232/GPIB/USB communication interface to meet various communication needs.
Idex Electronics is a professional instrument manufacturer with professional testing solutions in many fields such as automotive electronics, industry, battery, new energy, etc., always paying attention to the latest technology and market trends, and customers in more than 20 countries and regions around the world. .