适用于双模式场景下的三相四桥臂逆变器控制

Control Strategy for Three-phase Four-leg Double Mode Inverter

适用于并网与离网双模式工作条件下三相逆变器是并网型微电网的重要核心设备,在此基于三相四桥臂(3P4L)逆变器电路拓扑,提出了一种基于同步坐标系下解耦控制与空间矢量调制技术相结合的逆变器控制策略。该策略既保证逆变器在离网独立运行模式下可实现较高的直流电压利用率,解决不平衡负载条件下的机端三相电压平衡问题,又可实现在并网工作模式下的低谐波并网发电,且具有较强的低电压穿越(LVRT)能力。当微电网在并/离网模式的切换过程中,该控制策略能够实现负载电压冲击小、敏感性负载不间断供电运行。系统仿真及原理样机实验结果表明了所提控制策略的正确性和有效性。

A control strategy of compounding the decoupling control in the synchronous coordinate system and the space vector modulation based on the three-phase four-leg(3 P4 L)inverter,which makes the inverter operating in the stand-alone and grid-tied condition,as well the transfer seamlessly.The strategy can solve the problem of three phase unbalance voltage with the unbalance and nonlinear load in the stand alone mode.The inverter shows good low harmonic current performance and low voltage ride through(LVRT)capability in the grid-tied mode.Under the conditions of the complicated grid fault,the new strategy can reduce the voltage ripples and ensure uninterrupted power supply of these sensitive loads.The simulations and experimental results show the validity of proposed control strategy.