电压型逆变器分段死区补偿调制策略

刘和平 路莹超 王华斌 苗轶如

摘 要：针对电压源型逆变器中死区效应引起的电流谐波畸变问题，提出了一种分段混合式PWM死区抑制策略。一方面在电机定子电流的非过零区域根据电流方向仅动作一个桥臂，实现了死区消除，并针对由器件导通压降与开关延时产生的电压误差进行了修正；另一方面在过零区域采用脉冲等效时间补偿法抑制零电流钳位效应产生的非线性误差。此外在整个区域补偿开关管的开通关断延时及器件的导通压降造成的非线性误差。为了最大限度增加死区消除时间的占比，设计了上述两种调制策略之间的最优切换方法。仿真和實验结果表明，死区分段消除与补偿混合调制策略能够显著减小定子电流的谐波畸变率，并有效抑制死区效应对系统的影响，证明了该方法的有效性和实用性。

关键词：死区消除；死区补偿；电流过零区；谐波畸变率；电压型逆变器

DOI：10.15938/j.emc.（编辑填写）

中图分类号：TP 273 文献标志码：A 文章编号：1007 -449X（2018）00-0000-00（编辑填写）

Abstract： A subsection integrated deed-time effect suppression strategy is presented in this paper to suppress current harmonic distortion caused by deed-time effect in voltage source inverter. On one hand， deed-time is eliminated by controlling only one bridge leg according to stator current direction of motor in nonzero current zone， meanwhile the voltage error caused by conduction voltage drop and switch delay is corrected. On the other hand， nonlinear error caused by zero current clamping effect is decreased by equivalent time compensation method based on pulse in zero current zone. Furthermore， in order to maximally eliminate the deed-time， an optimal switch method of the proposed PWM strategies is designed. The simulation and experimental results show the reduction of total harmonic distortion（THD） of stator current and the suppression of the influence caused by deed-time on the system， which demonstrates the validity and practicability of the proposed method.

Keywords： dead-time elimination， dead-time compensation， zero current zone， total harmonic distortion， voltage source inverter