Research On The Control Of Pumped Storage Uint Based On Doubly-Fed Method

Nowadays, the power system construction of our country is in a stage of rapid development, there are electricity peak power supply tension, active reactive power reserve insufficient, low electricity transmission and distribution capacity utilization rate is not high and transmission efficiency is low, developing a pumped storage system with the features of peaking in valley, FM phase modulation, emergency and other functions is a important component of the new type of electric power system in China. According to the features of the traditional synchronous hydro-generator being inefficient and little adaptable to revolution, a pumped storage system based on doubly-fed method is presented, with the analysis of the mathematical model of doubly-fed induction generator, derivating the vector control method of pumped storage system based on doubly-fed, and the process of zero-velocity starting to network synchronization is list.Firstly, analyzing the doubly-fed type at home and abroad development situation and the trend of pumped storage power generation industry, then introducing the starting methods of pumped storage unit and the main control technology of DFIG.Secondly, analyzing the model of pumped storage unit based on doubly-fed method, then introducing the VSCF operation principle of DFIG and the coordinate transformation method, according to the mathematical model of doubly-fed induction motor, derivating its mathematical model under the three-phase stationary frame, the two-phase stationary frame and synchronous rotating stationary frame. According to the mathematical model of network side converter to derivate its vector control strategy, then with the PI control technology, the space vector pwm(svpwm) control technology and PLL control technology, establishing the block diagram of grid-side converter based on the grid voltage orientation, using Matlab/Simulink to establish its simulation model and the thorough analysis research. Through the analysis of doubly-fed induction motor rotor side converter control strategy, the zero-velocity starting control strategy based on rotor converter is proposed, the control strategy of network synchronization is derivated, and the process of zero-velocity starting to network synchronization is list. Simulation and experiment results show that the control strategy can realize the process of starting to network synchronization, it is comparatively easy and reliable.Finally, with a 2.2 kw doubly-fed induction generator as the prototype, building the doubly-fed type pumped storage system experimental platform. Introducing each hardware module function design and software process design, then completing the zero-velocity starting to network synchronization process of the doubly-fed type pumped storage system experiment.