Voltage Stability Analysis And Reactive Power Optimization Strategy In Distribution Network With Wind Power

Nowadays wind power generation is with the most nature development techniques and commercial prospect in new energy resources and develops rapidly. With the intelligent level improvement of distribution network, wind power installed capacity will increase gradually in the future, which is a good way of consuming the wind energy resource locally and improving the system voltage level but also brings some impact of the voltage stability and daily operation maintenance such as changing the traditional distribution network into a multi-source structure and the flow of network, causing the bus voltage violation and leading to the increasing actions time of control devices. It is of important theoretical value and practical significance to carry out research on the voltage stability of distribution network with wind power and optimizing reactive power compensation strategy so that the development and utilization of wind power can be more effectively.This article firstly does research on the reactive power adjustment range and maximum allowable penetration level of wind turbines and obtains the relation between the former and the active power output based on the steady state model of DFIG. Then taking the reactive power limitation of wind turbines and static security constraints of power system as prerequisite conditions, this article calculates the maximum allowable penetration level of wind turbines in distribution network, which proves that on the strategy of constant voltage, the distribution network can consume more wind power output.Secondly, carrying out research on the effect of control strategy, active power output and different location of the wind turbines to voltage stability of distribution network. The continuous power flow algorithm and voltage stability ratio based on Thevenin equivalent are used in this article. The example in IEEE 33 bus distribution system proves that the effect of constant voltage strategy is better than constant power factor strategy and dispersive access of wind turbines is better than integrated access.Finally, this article put forward a dynamic reactive power optimization strategy considering the voltage stability ratio. The access of wind turbines in distribution network has obvious effect on the adjustment of OLTC and the switching of compensation capacitance. The dynamic reactive power optimization strategy takes the daily constraint of control devices into account and the voltage stability ratio is also included in objective function. The optimization solved by adaptive particle swarm optimization algorithm can reduce the losses of power grid and improve the voltage stability at the same time when distributing the weight of objective function rationally. The effectiveness of the dynamic reactive power optimization strategy put forward in this article is proved by the examples in IEEE 33 bus distribution system and US PG&E 69 bus system. The research in this article offers practical applicable value.