The Wireless Parallel Control Technology Based On Modified Droop Chracteristic

Parallel inverters can increase the capacity and the reliability of inversion supply, parallel technology with interconnected wires has been relatively mature and products of multiple parallel inverters have appeared, however, as the number of parallel inverters increasing, the control wires among the inverters sharply increase, the ability of anti-jamming also reduces, wireless- parallel control technology has become the hot spots of parallel.Firstly, the paper study the control scheme of the inverter, establish the model of the inverter, deduce the output impedance, A dual closed-loop control with instantaneous voltage and current feedback control is employed to analysis inverter by simulation. The inverter mathematical model has been established, output impedance of the inverter has been deduced.Secondary, the forming reason of circulating current of the single-phase inverter parallel system has analyzed, various factors which impact on the circulating current are analyzed by simulation.An improved droop characteristic of control is adopted—adjusting the output voltage amplitude value by active power, adjusting the output voltage frequency by reactive power. This control mode can effectively control phase difference of output voltage by the simulation, and circulating current can obviously be restrained, thus achieves the objective of sharing load power.Finally, The improved droop character of control scheme is demonstrated in two inverters parallel experiment platforms. An experiment program of two inverters wireless-parallel is compiled. The experiment proved that this scheme have the good stable state and dynamic performance, moreover can completely realized parallel system's hot-plug and the true redundancy. The results indicated that the scheme can better realize control of parallel.