Design And Implementation Of Voltage Source Converter For Superconducting Magnetic Energy Storage

Energy storage technology has become a very important part in the process of powersystem operation, it can be used to achieve Flexible Alternative Current Transmission(FACT) in power system and maintain the stability of the power system, eliminating theclutter of the power grid. It also plays a vital role in micro-grid which is popular researchedin recent years. Energy storage technology can ensure the continuity and stability of thepower supply. The Superconducting Magnetic Energy Storage (SMES) technology is one ofthe most potential technologies in mainstream storage technologies, superconductingmagnetic energy converter technology has an indispensable position, and its performance isdirectly related to response speed and power exchange capacity of the energy storagedevice.A voltage source converter (VSC) for SMES is designed according to the needs of theproject, which consists of a three-phase PWM rectifier and a chopper. Through thecalculation of main circuit parameters, the research of control strategy and simulationpractice, we verify that the converter can achieve the performance that requires in theproject. In order to simulating the actual circuit, a voltage-type inverter prototype platformhas been set up, TMS320F2812type DSP is used as the master chip to control the prototype,dual closed-loop PI control, SVPWM high frequency output is used as the control strategy.The prototype is able to achieve the performance needed finally by System debugging. Itprovides reference basis for the realization of large-scale converter.In this paper, two core technologies in the control strategy, voltage and currentdecoupling technology and phase-locked loop technology, have been analyzed. Because ofthe impact of inductance parameter variation on decoupling, nonlinear decoupling controltechnology is proposed, the method can be completely decoupled without informing theexact value of inductance; relative to traditional phase-locked loop cannot be accuratelylocked when voltage is unbalance, the phase-locked method based on virtual reactive underthe coordinates of the stationary two-phase is proposed, and be verified the feasibility of themethod by experiments.