Voltage and Frequency Control of an Islanded Power System Based on Wind-Battery Generation

摘要

This paper focuses on voltage and frequency control of an islanded power system based on wind-battery generation with a double fed induction generator (DFIG), a power conditioning system (PCS), and a battery energy storage system (BESS). The PCS along with the BESS is used to supply the power demand for the DFIG and loads to form a virtual grid, behaving as a sole free-slack for the isolated system, and is adequately coordinated with the generated power of the DFIG, the energy of the BESS to keep the voltage and frequency at point of common coupling (PCC) to an acceptable level. The proposed control scheme, using only a voltage close-loop, has the capability of load balance and voltage regulation via regulating automatically the active/reactive power output of the PCS. And an efficient power balance mode is theoretically presented to make the system operate in the most effective way. The main components of the islanded system are modeled based on PSCAD/EMTDC and a 50 kW experimental platform is developed using the DSP processor. Simulation and experimental results show that the generation system can keep the voltage and frequency stability at desired level during different dynamic conditions like varying in loads and wind speed.