电动汽车驱动电机控制的脉冲宽度调制算法

SVPWM Modulation Algorithms in Motor Controller of Electric Vehicles

摘要:

续航里程是电动汽车应用的主要瓶颈，提高电机驱动系统的效率是突破该瓶颈的关键技术.逆变器损耗大、效率低不仅会影响电动汽车的续航里程，还会造成电动汽车冷却系统的散热负荷过大，限制逆变器的电流输出能力.为此通过对七段式SVPWM（空间矢量脉冲宽度调制）、FlatTop（平顶）SVPWM和半频式SVPWM进行比较研究，提出了一种组合式SVPWM方法，即在电动汽车的不同工况下使用不同的调制算法.经一辆电动汽车样车验证，所提方法可以使系统在减小逆变器开关器件损耗的同时，仍能具有相对较高的扭矩控制精度，从而提高其市场竞争力.

关键词:电动汽车; 电机驱动; 七段式SVPWM; FlatTop SVPWM; 半频式SVPWM; 逆变器损耗; 扭矩控制精度

Abstract:

Mileage is a major technical bottleneck in the application of electric vehicles. Therefore, improvement of the efficiency of the motor drive system is a key technology to breaking through the bottleneck. High power losses and low efficiencies of the inverter can not only affect the mileage of electric cars, but also cause high cooling system load of electric vehicles and limit the current output capacity of the inverter. In this paper, the sevensegment SVPWM, flattop SVPWM, and halffrequency SVPWM are compared and used in combination. That is, different modulation algorithms are used under different working conditions of electric vehicle, which makes the system have a low inverter loss and high torque accuracy, so as to improve their market competitiveness.

Key words:electric vehicle; motor drive; seven segment SVPWM; flat top SVPWM; half frequency SVPWM; inverter loss; torque accuracy