高频隔离型光伏并网逆变器拓扑及其控制策略  

Topology and Control Strategy of High Frequency Isolated PV Grid-Connected Inverter

作　　者：梁晖[1] 罗浩[1] 聂志强[1] 陈彪 

机构地区：[1]国家能源主动配电网技术研发中心(北京交通大学),北京市海淀区100044 [2]光宝通信(广州)有限公司北京海淀技术服务分公司,北京市海淀区100193

出　　处：《电网技术》2016年第8期2302-2308,共7页Power System Technology

基　　金：国家能源应用技术研究及工程示范项目(基于分层储能的主动配电网共性技术研究(NY20150301))~~

摘　　要：在全桥倍流DC/DC拓扑的基础上加以改进,提出了一种高频隔离光伏并网逆变器拓扑,所提拓扑保留了倍流电路电流纹波小等优点;且高频变压器输出经过一级变换直接输出低频交流,无直流环节,有利于提高系统效率。引入混合型正弦脉宽脉位调制(sinusoidal pulse width and position modulation,SPWPM)策略,将正弦调制和高频逆变功能均在前级逆变器完成;后级倍流电路工作在工频和高频混合模式,有利于减小开关管损耗及保证电流平滑换流。同时为消除并网电流控制策略中静态误差等问题,采用比例谐振(proportion resonant,PR)控制器代替传统的比例积分(proportion integral,PI)控制器。仿真分析和实验结果验证了所提控制策略的可行性。With improvements on full bridge doublecurrent DC/DC topology, a high frequency isolated photovoltaic grid- connected inverter is proposed in this paper. The new topology retains not only advantage of small current ripple in original DC/DC circuit, but also that high frequency transformer directly puts out low frequency AC through the first level transfer without DC link, which are helpful to improve system efficiency. By introducing hybrid SPWPM technology, sinusoidal modulation and high frequency inverter function is achieved in the first stage inverter, and post-stage circuit works in mixed state of linefrequency and high frequency, beneficial to reduce loss of switch tubes and guarantee smooth flow of current change. In order to eliminate static error in control strategy of grid connected current, PR（proportion resonant） controller is used to replace traditional PI（proportion integral） controller. Working principle and control strategy of the new inverter are deliberately analyzed. Feasibility of control strategy is verified with simulation analyses and experimental results.

关 键 词：光伏并网逆变器 高频隔离 混合型SPWPM PR控制器 

分 类 号：TM72[电气工程—电力系统及自动化]