Large Scale Wind Power Integration Technology Based On The Vanadium Redox Battery

With the increasing penetration of wind power generations in power system, the randomness and volatility of wind power makes it an threat of the stability and safety of the power system. This paper studied the application energy storage technology in the Doubly-fed Induction Generator (DFIG) wind power generation system to increase the stability and reliability of the power system.Firstly, this paper introduced the main energy storage technology. According to the require of the wind power generation, the Vanadium Redox Battery (VRB) with its outstanding characteristics is suitable for the wind power generation. By the analysis of the theory of the VRB and its parameters, this paper developed the electrical model of the battery based on the PSCAD/EMTDC. With the simulation the operation range of the State of Charge (SOC) and the power characteristic were determined.Secondly, the operating principle of DFIG was analyzed, and the mathematical model of DFIG was expressed in the three-phase stator stationary reference frame, and the d ? q two-phase rotating reference frame. The control strategy of rotor-side converter (RSC) and grid-side converter (GSC) were respectively based on the stator flux oriented method and stator voltage oriented method. During the voltage drop of the Point of Common Connection (PCC), the transient potential of the rotor was analyzed.The simulation of the DFIG and the VRB system was taken with the different installation positions of the VRB. Compared with the wind power without VRB, the simulation result showed that the VRB can smooth the wind power dynamically. During the voltage drop, when the VRB was parallel in the DC bus of the DFIG, it can maintain the voltage to protect the DC capacitor; when the VRB was parallel in the lower voltage side of the PCC it can generate active power to maintain the voltage level.