Research on Parallel Control Technology of PV Off-grid Inverter

The mathematical model of a parallel stand-alone photovoltaic inverter system analyzed the basic principle of wireless droop parallel flow control with an improved droop control algorithm based on active power frequency and voltage. Moreover, the scheme of the dual closed-loop control with addition of virtual impedance was put forward simultaneously. Model and simulation of a parallel system were carried out in MATLAB simulation, and a parallel hardware platform with two inverters of 3kW was built and analyzed. The simulation and experiment both proved that the photovoltaic inverter could share the reactive and the active power of the system with good static and dynamic performance.