新型无刷直流电机逆变电路功耗分析

全面分析了无刷直流电机驱动系统的逆变电路功率损耗，针对PWM调制关断时续流损耗较大的缺点，提出一种新型驱动逆变电路。此新型电路基于常规三相逆变电路，在每个半桥臂一侧并联一个反向二极管，达到减小续流压降的效果。通过与常规驱动电路的对比，分析了新型驱动电路减小压降的原理，并进行了实验研究。结果表明，此新型电路降低了续流时二极管的导通压降，进而减小了续流损耗，有利于实现无刷直流电机驱动系统的高效控制。

Analysis of Power Losses in Novel Brushless DC Motor Inverter Circuit

This paper, targeting the problem of large freewheeling loss in shutting down the pulse width modulation (PWM), proposed a novel drive inverter circuit based on the comprehensive analysis of inverter circuit power losses in the brushless DC motor (BLDCM) drive system. A reverse diode was connected in parallel, based on conventional three-phase inverter circuit, on the side of each half-bridge arm in order to reduce the freewheeling voltage. The principle of voltage sag mitigation was analyzed by comparing the conventional drive circuit, based on which, the experiment was carried out. It turned out that the novel circuit reduced the voltage drop of the freewheeling diode, and thus cut down the freewheeling loss, which would benefit the efficient control of the BLDCM drive system.