Experimental study on reactive power management in inverter-interfaced distributed generation system

The escalating demand of reactive power consumption by the load in the grid connected system usually causes the following problems 1) Voltage sag and swell at the point of common coupling (PCC) 2) Harmonic distortion of the grid current 4) low power factor etc. More over, to meet the rising reactive power load demand, distributed generation (DG) is a viable option. For that, usually current regulated PWM voltage-source inverters (VSI) are used to inter face DG with utility grid in order to ensure the grid stability. In this paper, reactive power compensation for inverter interfaced DG system based on hysteresis with proportional integral (PI) controller is proposed along with independent control of active and reactive power of the grid. The hysteresis with PI controller can largely reduce the current harmonics at PCC considerably which ensures lower total harmonic distortion (THD) during reactive power load demand increases. The performance indices include THD of the grid current, fast current tracking during steady state and transient conditions. The studied system is modeled and simulated in the MATLAB Simulink environment. Further, an experimental work has been carried out in the laboratory set-up in the discrete-domain via TMS320F2812 digital signal processor (DSP) and we could find there is an effective validation with simulated results.