電壓型逆變器分段死區補償調制策略

劉和平 路瑩超 王華斌 苗軼如

摘 要：針對電壓源型逆變器中死區效應引起的電流諧波畸變問題，提出了一種分段混合式PWM死區抑制策略。一方面在電機定子電流的非過零區域根據電流方向僅動作一個橋臂，實現了死區消除，并針對由器件導通壓降與開關延時產生的電壓誤差進行了修正；另一方面在過零區域采用脈沖等效時間補償法抑制零電流鉗位效應產生的非線性誤差。此外在整個區域補償開關管的開通關斷延時及器件的導通壓降造成的非線性誤差。為了最大限度增加死區消除時間的占比，設計了上述兩種調制策略之間的最優切換方法。仿真和實驗結果表明，死區分段消除與補償混合調制策略能夠顯著減小定子電流的諧波畸變率，并有效抑制死區效應對系統的影響，證明了該方法的有效性和實用性。

關鍵詞：死區消除；死區補償；電流過零區；諧波畸變率；電壓型逆變器

DOI：10.15938/j.emc.（編輯填寫）

中圖分類號：TP 273 文獻標志碼：A 文章編號：1007 -449X（2018）00-0000-00（編輯填寫）

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