Reactive Power Optimization Control Strategy For Distribution Network With Distributed Wind Power

With more sophisticated technology of wind power, it has become an important part of China’s electric power industry. States enact policies to encourage the development of distributed wind power. Distributed wind power access to low voltage distribution system in disperses and multi-spots. Stochastic and intermittent characteristics of wind energy will cause the frequent change of power flow and voltage, and bring adverse impact to the power grid operation. Making reactive power optimization control strategy will help solve this problem. In this paper, distribution network as research object, according to the operation characteristics of different reactive power compensation equipment in distribution system, related control strategies are designated, the specific work is as follows:1. Characteristics of active and reactive power output and operating of reactive power compensation device in distribution network are researched. Analysising reactive power compensation devices in distribution network equipment configuration guidelines, conclusions are given which are about how to choose capacitance and the location where reactive power compensation devices are located and about the reactive power control strategy of these devices.2. Considering the randomness and volatility of wind power, the operation conditions of power distribution network in different situations are evaluated, such as different types of wind turbine, interconnected locations or network load.Then by introducing network voltage and loss improving indicators and using the Newton-Raphson method to calculate load flow, the degree of the influence of distribution network loss and voltage when distributed wind power integrated is analyzed.Using measured wind power output and load data and simulating on the IEEE33node system, effect regularity of distributed wind power on distribution network is researched.The research achievement provide beneficial references for the grid integration of distributed wind power.3. Considering the effect of distributed wind power on distributed netword, reactive power optimization control strategy is developed:daily reactive power optimization control and short time reactive power optimization control. Taking into account of the number of switching capacitor bank switching limits, and reactive power cannot be continuously adjustabled, daily reactive power optimization control strategy is developed, decision variables for optimization are capacitor swiching time and capacity and the objective function is the active power loss all day long. According to the characteristics of SVC/SVG and wind power generator that the recative power of them is adjustable in succession, the hourly reactive power optimization control strategy is made. The decision variables for optimization are capacity of SVC/SVG and wind power generator and the objective function is the voltage excursion. Effectiveness of the proposed optimization strategy is verified through simulating on an actual power grid.