光伏并网逆变器的定频滞环电流控制新方法

提出一种用于光伏发电系统与公用电网并网的逆变器定频滞环电流控制新方法,该方法首先基于电网线电压空间矢量将复平面分为6个扇区,在每个扇区内实现两相开关解耦分别控制相应的线电流;然后,在控制相的下一个线电流误差周期到来时,计算并调节下一周期的滞环宽度以达到定频滞环电流跟踪,改善输出电流波形,提高控制精度。该方法的主要特点是不需要额外的模拟电路便可以实现开关频率的稳定。利用Matlab进行建模,仿真结果证明了该方法对稳定滞环开关频率是有效的,同时也表明该方法应用于光伏并网逆变器是可行的。

Constant-frequency hysteresis current control of PV grid-connected inverter

A constant - frequency hysteresis current control method for PV grid - connected inverter is proposed,in which the complex plane is divided into six sectors based on grid line voltage space vector and the two - phase switch decoupling is realized in every sector to respectively control cor - responding line currents. When the next current error cycle of controlled phase comes,the hysteresis band of that cycle is calculated and regulated to track the constant - frequency hysteresis current and improve the output current waveform and control accuracy. The stable switching frequency is thus achieved without additional analog circuitry. Simulation model is built with Matlab and the simu - lative results verify its validity and feasibility.