Research On Torque Ripple Reduction Of Switched Reluctance Motor In Electric Vehicles

In recent years, environmental problems are becoming more and more serious, so that people of energy saving and environmental protection, electric vehicles attention continued to increase, as well as the government's preferential policies for the electric vehicle industry in the implementation, making more and more people in the purchase of cars are more likely to buy electric cars. Switched reluctance motor has the characteristics of simple structure, stable operation, large starting torque, small starting current, and suitable for frequent start and stop, which has become a research hotspot in the electric vehicle drive system. However, due to the disadvantage of the switched reluctance motor in low speed torque ripple, it also limits its commercial application in the electric vehicle industry.The switched reluctance motor (SRM) the low-speed torque ripple suppression strategy research. Firstly, the paper introduces the switched reluctance motor (SRM) is a basic operation principle and linear model, of common switch reluctance motor torque ripple suppression strategies are analyzed and compared. Proposed an adaptive torque sharing function of control strategy, for a low speed under different rotational speed using adaptive waveform factor to change the current rise and decline rate, joined the current compensation coefficient in order to decrease the current error. In order to verify the validity of the function, the FEMM software is used to analyze the electromagnetic field, and the data is obtained and the nonlinear simulation model of the prototype is built in MATLAB/Simulink. In the simulation experiment, the current and torque waveforms under different control modes are compared and analyzed, which verifies the effectiveness of the adaptive torque sharing function in the low speed torque ripple suppression.Switch reluctance motor driving control strategy for electric vehicle in different working conditions stable and quick start for electric vehicles, using the uniform acceleration starting control strategy; in low speed running torque ripple suppression, the use of the adaptive torque sharing function; to improve the safety of high braking and a mileage, the use of the mechanical and electrical braking combined braking control strategy is introduced in this paper.According to the requirement of the enterprise, the driving platform of the main control chip based on TMS320F28069 is designed, including the power conversion circuit, the acquisition circuit, the position signal detection and the communication circuit. In recent years, some advanced control methods are introduced into the control of switched reluctance motor, and then the original front and back system will make the program more massive and not easy to be modified and transplanted later. So in terms of software will be front and back office system change for sequential operation system, using the modular programming, on task management and use of priority scheduling, each task running time more determined, to reduce unnecessary interruption and delay the effects of the program, reasonable use of the chip of idle resources, improve the running efficiency of the CPU. Software internal design includes the main program, speed calculation, control strategy and so on. In the prototype platform of the enterprise, the effectiveness of the torque ripple suppression of the adaptive torque distribution function is tested, and the feasibility of the sequential operating system is tested.