Study on Hardware-in-the-loop Model and Low Voltage Ride-through Characteristics of Photovoltaic Power Station

In order to prevent large-scale disconnection accidents of photovoltaic power stations caused by voltage fluctuations and faults in power grids, low voltage ride-through characteristics and other detection tests are needed when photovoltaic power stations are connected to power grids. At present, field test and type test are the main methods of detection, but due to the limitation of detection devices and test conditions, the evaluation of low voltage ride-through characteristics of photovoltaic power stations still remains in the single-machine detection mode, which ignores the interaction between photovoltaic inverters and inverters, inverters and static var generator(SVG) devices. The test results cannot truly reflect the low voltage traversing characteristics of the photovoltaic power stations. Using RT-LAB hardware-in-the-loop simulation platform, real photovoltaic inverters and SVG controllers are introduced to build simulation models of photovoltaic power stations. The differences between single-machine detection of photovoltaic inverters and reactive power compensation devices and low-voltage ride-through characteristics detection of the whole station are compared and studied. The simulation results show that, compared with the stand-alone test, the whole station simulation modeling test method can reflect the voltage rise caused by the reactive power characteristics of photovoltaic inverters and SVG devices after the drop, and more truly reflect the low voltage traversing characteristics of photovoltaic power stations.