Research On Modelling Of Single-Phase Parallel Inverter System Based On Networked Control And Droop Method

As the quick development of the mobile office, communications, transportation etc., the inverter power supply system are used more widely. Also the power supply capacity, precision, stability requirements are getting higher and higher, a single inverter can no longer meet the requirements. Inverter parallel system can effectively solve these problems, in order to provide high-precision, high-feasibity power system.Compared to the interconnected system, the droop method controlled inverter parallel system without internal connections has better redundancy, and the system is more convenient to build, although the current-sharing feature is a little worse than the interconnected system. In view of the rapid development of networked control, this dissertation would try to join network into the droop method controlled inverter parallel system in order to increase the performance of parallel system.The dissertation describes the control theory of the droop method. The model of the parallel inverter system based on droop method is given, through the state-space equation, Frequency-modulation(FM) signal modeling method and so on. The simulation and experimental results on different lead impedance are given out.The dissertation also model the system under both networked control and droop method. Then analysis the effects brought in by the networked control, for example, the network time-delay, data packet loss and so on. The paper also presents methods for network time-delay analysis of different network communication protocols. At last, the experiment result of the parallel inverter system with networked control and droop method is given, and it verifies the ascendance of the networked control.