Application Of Super Capacitive Energy Storage System In Low Voltage Passing Through Wind Power Generation

As the fossil energy depletion, environmental issues have become increasingly prominent. People pay more and more attention to the development of new renewable energy. Wind energy is a clean and renewable energy, global reserves is 10 times that of earth on the development and use of the water of the total reserves. Therefore, wind power is becoming more and more important for all over the world. However, with the increase of the size of the grid connected wind turbine, the randomness of the wind with the volatility of wind power output is the impact on the power system is more and more big. Especially the wind power of low voltage ride through lead to a large area of wind turbine off grid operation easily, it is seriously affecting the normal operation of the power grid.This paper makes in contrast to the existing energy storage method,according to the wind turbine capacity designed a super capacitor energy storage device to control of DC link peak when the process of the low voltage ride through happening. The specific work is as follows:According to the wind power requirements for low voltage ride through, designed a super capacitor energy storage device. Introduced the theory of electric double layer capacitor and its advantages. According to the super capacitor charging and discharging speed and between the capacitor voltage balance reasons, contrasting the advantage and using place of isolated topology with isolated topology, proposed a new series-bidirectional BUCK/BOOST topology. When it is in charging, it works in the mode of BUCK. When it is discharging, it works in the mode of BOOST. Study on the basic working principle of the main circuit, calculation of the main parameters of the main circuit and device selection. For the super capacitor group parameters are not completely equal may lead to voltage imbalance, an active voltage balancing circuit was designed. Studied the working principle of the circuit and the calculation and selection of the device.And this paper calculated the small signal model of bi-directional DC/DC converter, according to the actual needs designed PI control parameters and established a stable loop. This paper designed sampling circuit, the idea of main progress, the control scheme of the system are presented.Finally, a 150 KW experimental prototype was designed. Super capacitor charging and discharging experiments, short circuit protection system experiments have been done. These experiments verified the function and significance of converter.