Research On Control Algorithm Of Servo Driver For Electric Vehicle

With the development of science and technology,and the crisis of energy and the environment,electric vehicles is getting more and more important in the future areas of traffic.it is very important to study the corresponding servo drive algorithm for the development of electric vehicle.The traditional control algorithms include vector control and direct torque control,and the most widely used algorithm is the vector control algorithm.Based on the model and simulation of this two algorithm,the advantages and disadvantages are summarized and the new algorithms are proposed.The classical vector control algorithm is highly dependent on the mathematical model of the motor,so that the current loop needs current value to be fed back to the PI control.As a result the current sensor is indispensable and the cost is high.The PI parameters are set dependent on the motor parameters,But the parameters changed when the motor is running,resulting in poor control results;classic PWM wave using the classic seven-segment algorithm,which resute in the overheating of IGBT while the drive are heavy loaded.Based on the study of traditional algorithms,puts forward some algorithms to solve the above problems.(1)The four-segment space vector pulse lgorithm can realize the same output effect as the classical lgorithm wiht low switching frequency of IGBT,When the motor worked in high speed,it has an output that is closer to the desired vector than the classic algorithm.(2)Voltage control algorithm without current sensor,which can realize Id = 0 in the absence of current sensor,and work stably at closed speed loop.(3)The direct current control algorithm,The algorithm combines the vector control and the idea of direct torque control to improve the response speed of current loop,and it can reduce the dependence of parameters of the motor to improve the robustness of the control.The simulation of these lgorithms show that results can achieve the expected results.Finally,based on TI's DSP chip,with the experimental of these lgorithm,the results show that above algorithms can achieve the desired effect under the expected conditions.