Design And Implementation Of A Test Bench For Electric Vehicle Propulsion Drives

Propulsion drives are the critical components of electric vehicles,and test bench serves as a useful platform for evaluating the propulsiondrives of electric vehicles. The conditions, such as frequent accelerationsand decelerations, multiple stops, and stochastic velocity changes, mustbe met in the propulsion drives during vehicle going. Therefore, EV pro-pulsion drive should be verified by forcing it to follow the test cycles thatreproduce the actual operating conditions. The realization of drive cycleis the key to simulate driving resistance accurately.In view of multi-factor, non-linear characteristics of the test benchfor electric vehicle, and difficult to simulate vehicle inertia accurately, akind of test bench which can dynamic load to EV driving system, is de-signed. Such a test bench uses the AC electric dynamometer system toachieve the simulation of road resistance and vehicle inertia resistancewhich is based on electrical inertia simulation technology. The researchworks of this paper are as follows:For vehicles inertial resistance force is difficult to simulate, positiveinertia compensation approach is discussed which are based on electricalinertia simulation technology, and the control scheme based on equivalentvehicle rotational inertia is developed through the simulation test bench.The results obtained from the simulation showed that this platform canreproduce the behavior of electric vehicle and validated overall effec-tiveness of the implemented control approach.The overall scheme of the test platform is determined according tothe requirements of dynamic testing and energy saving. An energy feed-back type is used by the test platform: the four quadrant DC regulatedpower is used to feedback the energy to grid by inverter, which is gener-ated by the tested propulsion drives when it works in regenerative braking.As a loading device, When the AC electric dynamometers work as a ge-nerator, the energy can be feedback to grid through the four-quadrant in-verter (dynamometers controller).Finally, hardware selection and communication control scheme de- sign of the test bench has been carried on, furthermore, debugging of thedc power supply and conducting part of the type testing of motor and itscontroller. The experimental results showed that the test bench can con-duct various projects of Propulsion drives and be capable of simulatingdrive cycle.