光电互补供电下光照变化剧烈时电网的功率补偿控制

Study on Power Compensation Control of the Power Grid when the Light Changes Drastically under the Photoelectric Complementary Power Supply

提出了光电互补同时供电的系统模型,对于市电PWM整流部分采用了模型预测直接功率控制。结合应用场景分析了在光伏供电严重波动情况下传统电压PI外环控制本身的滞后性,以及该控制下直流母线电压较大超调的过程。针对以上的问题,提出了将负载功率和光伏输出功率引入到模型预测直接功率控制环中,并与传统PI外环切换控制的策略。经过仿真验证,在光照剧烈变化时,所提控制策略的直流电压变化量比传统的电压PI外环控制策略小,对网侧电流的快速傅立叶变换分析也证明了所提策略的谐波含量更少,进一步验证了所提策略的优越性。

In this paper,a system model of photoelectric complementary simultaneous power supply is proposed,and model predictive direct power control is used for the PWM rectifier. Based on the application,the hysteresis of the traditional voltage PI outer loop control itself under the severe fluctuation of photovoltaic power supply is analyzed,and the process of large overshoot of the DC bus voltage under the control is also analyzed. In order to deal with the problem mentioned above,a strategy is put forward,that is to introduce the load power and PV output power into the model predictive direct power control loop,and control switching with the traditional PI outer loop. After simulation,it is found that the DC voltage variation of the proposed control strategy is smaller than that of the traditional voltage PI outer loop control strategy when the light changes drastically. The fast Fourier transform(FFT)analysis of the grid side current also proves that the proposed strategy has less harmonic content,which further verifies the superiority of the proposed strategy.