Harmonic Modeling and Interaction Characteristic Analysis of Grid-Connected PVs

Compared with other energy sources, solar energy has incomparable advantages in the process of development and utilization. However, the harmonic interaction between inverter and power grid is a potential threat to the stability and reliability of the system. Through the establishment of harmonic domain mathematical model, the paper analyzes the grid-connected characteristics of PV power stations, and plays a guiding role in the improvement of power quality after grid-connected. First, in order to build an inverter output impedance model close to the actual grid-connected system, the paper proposes to take the non-ideal characteristics of deadtime effect and modulation effect of the inverter into the model to increase its accuracy. Then, the paper utilizes the proposed inverter non-ideal characteristic model to conduct harmonic domain modeling and harmonic interaction analysis for PV grid-connected system. At last, the simulation results of harmonic domain model verify the correctness and effectiveness of the proposed modeling method and harmonic interaction analysis method.