Adaptive Damping Factor Control Strategy of Inverter Interfaced Distributed Generators Based on Virtual Synchronous Generator Technology

With development of new energy, inverter interfaced distributed generator (IIDG) has become one of the main types of distributed generator. Its control strategy has great influence on the dynamic behavior of distribution network. Conventional control modes can not provide inertia and are prone to instability. Based on the technology of virtual synchronous generator (VSG), the active power and frequency (P-o)) control, voltage and reactive power (Q-v) control and the inner loop control of IIDG are optimized respectively. The stability model is established after the transfer function of the system is derived, and the effect of damping factor on the output of the IIDG is analyzed. Based on the mechanism of stability, an adaptive damping control strategy is proposed. The strategy takes the deviation of output power as feedback and it can adaptively regulate the damping factor of the IIDG system. Hence the system has the advantages of fast response speed and small dynamic fluctuation. The strategy is evaluated by simulations based onPSCAD/EMTDC, which indicate that the adaptive damping control strategy has remarkable better dynamic performance compared with the fixed damping factor.