两种控制策略下电动汽车逆变器功率损耗的近似计算

Approximate calculation of electric-vehicle inverter power-loss in two control strategies

为了选择电动汽车永磁同步电机功率模块,设计散热装置,并提高其驱动系统的效率,提出了一种计算逆变器功率损耗的近似方法。针对驱动系统中常用的对空间矢量脉冲调制(SVPWM),根据绝缘栅双极型晶体管(IGBT)的特性及参数,积分计算了SVPWM中不同扇区的功率损耗。比较了在d轴电枢电流为零时和最大转矩电流比的两种控制策略下的逆变器功率损耗。结果表明:两者相比之下,在最大转矩电流比控制策略下,逆变器的功率损耗较小,从而逆变器散热器温升也较低。

An approximation method for calculating inverter power loss was proposed to guide selecting power module and design heat sink with higher efficiency of permanent magnet synchronous motors for space vector pulse width modulations （SVPWM） which are widely used in the electric vehicle drive system. Power losses in different vector sectors were calculated using this method, and then compared according to the characteristics and parameters of insulated gate bipolar transistors （IGBTs） for two drive-system control-strategies of permanent magnet synchronous motors. For one control strategy, the d-axis armature current is zero 0, and the other is with the maximum torque per Ampere （MTPA）. The results show that the total power loss of the inverter under the MTPA control strategy is smaller than that for the other control strategy, thereby resulting in lower temperature rise of inverter heat sink.