采用垂直多载波调制技术的并网逆变器  

A grid-connected inverter based on vertical layered multi-carrier modulation strategy

作　　者：胡雪峰[1,2] 龚春英[1] 陈新[1] 

机构地区：[1]南京航空航天大学江苏省新能源发电与电能变换重点实验室,江苏南京210016 [2]安徽工业大学电力电子与运动控制省重点实验室,安徽马鞍山243002

出　　处：《电机与控制学报》2011年第7期60-64,70,共6页Electric Machines and Control

基　　金：安徽省教育厅自然科学重点基金(KJ2007A109ZC);国家重点基础研究发展计划(973计划)项目(2007CB210303)

摘　　要：在电压源型PWM并网逆变器的设计时,通常用设置开关延时(死区)的方法来避免直流链的短路现象。这种方法将会降低并网逆变器的输出性能,即产生"死区效应"。为解决上述问题,提出一种基于垂直分层多载波的新型复合功能PWM调制策略。与传统的分别进行死区时间设置和基于电压伏秒平衡的死区补偿方法相比,垂直分层多载波PWM调制策略具有双重功能:既能设置开关延时以防止直流链短路现象的发生,又能避免桥臂输出脉冲电压产生偏差而引起的"死区效应",理论上能完全消除由"死区效应"引起的并网逆变器入网电流波形畸变问题,且给出了仿真和试验结果,证明了该策略的有效性。In the grid-connected inverters, it is necessary to insert a switching delay time（dead-time） in sinusoidal pulse width modulation （SPWM） for preventing a short circuit in the dc link. This causes dead-time effect which distorts the output voltage and current, and does harm to the power networks. To solve this problem, a vertical layered multi-carrier SPWM modulation strategy was proposed based on a detailed analysis of the relationship between switch delay and the bridge leg output voltage deviation. This strategy can set proper dead time around gate driving pulses while maintaining the correct volt-second of the output voltage. Compared to the conventional dead time compensation by average voltage correction, the proposed PWM strategy can ensure accuracy of output voltage and dynamic response, and improve the quality of grid current. Simulation and experimental results show the validity of the analysis and verify the effectiveness of the proposed PWM strategy for grid-connected inverter.

关 键 词：复合功能PWM调制 并网逆变器 死区效应 谐波抑制 

分 类 号：TM464[电气工程—电器]