Research and Design of a Monitoring Device for Distributed Photovoltaic Power Station

A monitoring device for distributed photovoltaic power stations has been developed to diminish the impact of intermittent and random power generation on the grid voltage and frequency. Firstly， the basic principle of the device and the design of hardware and software are introduced. Secondly， to give full play to the inverters' fast and continuous reactive power and active power adjustment capability， an improved incremental PID （proportional-integral-derivative） control and primary frequency modulation curve are used for reactive power/voltage control and active power/frequency control respectively. Finally， the simulation results， reactive power following test， primary frequency regulation test， and on-site voltage regulation test results have verified the device’s enormous voltage regulation and frequency regulation capabilities.