三相并网逆变器的控制与死区补偿

Control and Dead-zone Compensation on Three-phase Grid-connected Inverter

针对三相并网逆变器,详细分析了空间矢量脉宽调制(SVPWM)中死区效应对并网电流的影响,对死区效应引起的误差矢量进行数学建模,讨论了误差矢量与三相电流方向的关系。采用电流矢量来判断电压补偿扇区,避免了电流检测中出现多个过零点的现象,提高了补偿精度。最后,采用TMS320F2812控制芯片,结合功率解耦、电压前馈等控制方法补偿死区效应,在应用于风力发电的逆变器上得到了很好的效果。

Based on three-phase grid-connected inverter,this paper analyses the dead-zone effect on network current in space vector PWM,set up the mathematical model of error vector caused by dead-zone effect,and discusses the relationship between error vector and the direction of three-phase current.A voltage compensation method by using current vector to deter mine the compensation sector is applied to avoid the phenomenon of multiple zero-crossing current detection and improve the compensation accuracy.A wind power inverter controlled by TMS320F2812 is designed with control strategies of power decoupling,voltage feed-forward and dead-zone compensation,then simulations and experiments prove satisfied results.