双模式逆变器无缝切换控制策略的仿真分析

Simulation Analysis of Seamless Transfer Control Stratagy of Dual-mode Inverter

风力发电中,为了保证重要负载的不间断供电及电网故障时风电系统的及时脱网,就需要使逆变器能够在离网与并网双模式下平滑切换。故分别设计了逆变器离网与并网模式的控制策略,实现了离网运行时重要负载正常工作,并网运行时单位功率因数并网,在此基础上以减少两种模式切换过程中的电压电流冲击为目标,设计了两种模式的无缝切换方法,最后通过仿真验证了设计的正确性和合理性。

In wind power generation system, an important load must be provided uninterrupted power supply, and when the grid fault occurs, wind power generation system could take off the grid-net in time. So, the grid-connected inverter should implement seamless transfer between grid-connected mode and stand-alone mode. This paper designs and implements a stand-alone/grid-connect mode inverter. Based on analyzing the control strategy of stand-alone and grid-connect modes detailed, for the purpose to reduce the voltage and current impact of switching process, a seamless switch method is designed between both states. Meanwhile, this method was modeled and simulated in MATLAB/Simulink software, the simulation results verified its feasibility and correctness.