Parameter Identification and Modeling of Photovoltaic Power Generation Systems Based on LVRT Tests

With the increasing usage of photovoltaic (PV) generation systems, it is of great relevance to develop effective models to characterise the dynamic behaviours of actual PV systems under different failures and operation modes. In general, three test items are required to identify the three types of parameters, namely, the low-voltage ride-through (LVRT) control parameters, PV array parameters, and DC voltage loop parameters. To simplify the test items and steps needed for parameter identification, an appropriate identification and modelling method for a PV generation system is proposed on the basis of an LVRT test. This LVRT field test is conducted on a large PV system in North China. The three groups of parameters are identified with the test data. Specifically, the equivalent resistance of the collection line of a PV array is considered to accurately simulate the dynamic process of DC voltage. Lastly, the effectiveness of the proposed method is verified through a comparison of simulation results and field test results.