The Research Of Reactive Current Detection And Control Method On Static Var Generator

Static Var Generator(SVG) as an important means of reactive power compensation and harmonic suppression is getting more and more attention. This paper establishes the mathematical model,and analyzes the detection and control methods of reactive current, it makes Static Var Generator(SVG) can compensate the reactive component, negative sequence component and harmonic component of the load current.Based on the existing reactive power and harmonic current detection method, this paper proposes a reactive current detection method based on instantaneous symmetrical component method and ip-iq algorithm. It gets fundamental active power component of load current side by this method,and subtract fundamental active power component from the load current,so it can get the component of compensating. it adopted double closed loop strategy of the Current Closed Loop and Voltage Closed Loop,this can realize the purpose of reactive power compensation,three phase unbalance compensation and harmonic suppressionAt last, building simulation model of Static Var Generator(SVG) by using MATLAB/Simulink,the system model is simulated and verified under the condition of three-phase balance and three-phase unbalanced,the waveforms of the voltage and current are obtained of before and after compensation,and the compensation current is analyzed by FFT. The results show that the phase of three-phase voltage and current are basically the same after the reactive load or capacitive load is compensated, and the total harmonic distortion(THD) is decreased by 11.7% after the harmonic load is compensated, the phase of three-phase voltage and current are basically the same and the total harmonic distortion(THD) is decreased by 10.52% after the reactive load that has harmonics is compensated, the phase of three-phase voltage and current are basically the same and the amplitude of the three phase current is almost equal after the load is compensated when the three-phase load is unbalanced, and the compensation effect of the Static Var Generator(SVG) is not affected after the load is compensated when three-phase unbalance degree is 4.05%.