Research on the strategy of cooperative control between photovoltaic grid-connected and reactive power compensation technology

When connecting a large number of generating sets into power grid, there will be the harmonic wave generated in power grid causing voltage and current distortion, which affects power quality seriously. Based on the instantaneous reactive power theory, the active current, reactive current and harmonic current can be real-time monitored. The P–Q method can be adopted to control reactive power compensation. By building the converter control model, the variation of reactive power of power grid between photovoltaic grid-connected inverter working under stand-alone mode and grid-connected mode can be analysed via a simulation system. The experimental analysis of reactive power compensation and harmonic suppression, the availability of the control strategy of the photovoltaic grid-connected inverter system can be proved. Using this novel strategy, the photovoltaic grid-connected power system can not only provide active power but also compensate reactive power and suppress harmonic, which will improve power quality.