Research On Applicaton Of Energy Storage And FACTS In Photovoltaic Generation System

The demand for renewable energy generation has been promoted because of the depletion of the traditional fossil energy and the increase of the environmental pollution. Nowadays, grid-connection, power fluctuations and power quality are several of the research emphasizes of renewable energy generation. This paper will be studied from the aspects of PV grid-connection, the control strategy of microgrid, the suppression of power fluctuation by hybrid energy storage and the application of FACTS in PV generation.Firstly, the paper analysed the characteristics and tendencies of the renewable energy generation through comparisons of several organizational forms (centralized and distributed renewable energy generation, microgrid and active distribution network). After summarizing the characteristics of various kinds of energy storage, power prediction and optimal configurations of hybrid energy storage are explained. Power allocation methods and circuit topology of coordinated-controlled hybrid storage are analysed. The necessity of the application of FACTS in renewable energy generation is analysed.A method is presented to calculate actual output current by known parameters. The simulation model of the PV cell shows the U-I and P-U features under different light intensity and different cell temperature. MPPT control model on the basis of voltage disturbance observation and the PV grid-connected model is built. Both models perform well in tracking accuracy and adjusting speed when light intensity and cell temperature change.The PQ control, droop control and V//f control of MG is simulated.A model of storage battery under constant current and voltage discharge is laid out. A model of super capacitor under constant current charge is laid out. The structure and characteristics of bidirectional Buck-Boost, Buck/Boost, Cuk, Zeta-Sepic convertor is analysed. Storage battery and super capacitor is used to reduce the power fluctuation in the simulation.The structure and characteristics of SVC, SVG, APF, DVR and SSTS is analysed. The simulation circuits of SVC, SVG, APF, DVR and SSTS are established.. The results show that SVC and SVG can compensate the reactive power effectively. APF can reduce the harmonic waves effectively. DVR can support the voltage when it’s going down. SSTS can switch the load to the stand-by power quickly when the PV generation gets out of order. A method to coordinate SVC and SVG is put forward for reducing voltage flicker.