一种低压电动汽车用逆变器非线性因素的新型补偿方法

In view of the low voltage and high current working condition in the voltage source inverter of low-voltage electric vehicle, by considering the nonlinear factors such as the dead-time and the turn-on/off delay of power device, especially, the voltage drop across the power device was taken into consideration. After that, the inverter output characteristic equation was established. Based on the output characteristic equation and the reference voltage, the error could be derived, thus it will accurately be compensated under the low voltage and high current working condition. At the same time, accurate current polarity is essential during the nonlinear characteristic compensation. However, the current ripple and the zero current clamp effect exist near the zero of phase current, which will result in inaccurate current polarity detection. So a method of reverse compensation was proposed to make the current pass zero in advance, which avoids the complicated determination and calculation of current polarity near the zero of current, in the meantime, the nonlinear characteristic of VSI was compensated effectively, too. Finally, the accuracy and feasibility of the proposed inverter output characteristic equation and compensation method are proved by simulation and experimental results. © 2020, Harbin University of Science and Technology Publication. All right reserved.