A Voltage and Frequency Droop Control Method with Autonomous Power Amplitude Limiting

Base on the analysis of multi Distributed Generators (DG) paralleled with different droop control characteristics in smart grid, this paper points out that the difference of droop control characteristics would lead to the DGs´ output power allocation unbalanced, and furthermore, may cause some of the DGs overload or even shutting down before the smart grid load reaches the maximum generating capacity. In order to protect the DG from overload and realize the maximum use of the smart grid generating capacity, this paper provides a voltage and frequency droop control method for DG with maximum and minimum power excursions. Experimentations on simulation and a smart grid platform with two 25kVA three phase inverters and a 30kW adjustable three phase resistance load have been done. Detail simulation results and experimental waveforms are shown in this paper to prove the performance of this control method.