| This paper focuses on issue that the influence fluctuations in load have on grid’s and power users’ voltage quality has been increasingly prominent, especially when the special powers users such as large industrial users and high-speed rail develops by leaps and bounds. The conventional reactive power optimization methods usually do not consider the changes of loads, and carry out calculation of the system in a deterministic state. Due to the various changes of power load fluctuations, when multiple fluctuate sources act together, it is difficult to describe the system with one certain state. So that using deterministic state to carry on optimization planning will result in difficulty to realize the integrated optimal goals, there is a problem that reactive power optimal measures cannot satisfy the variety of system’s operating status and its economic requirements.The main study object of this paper is the power users with significant load fluctuation, it discusses voltage quality problems such as voltage deviation and voltage fluctuations which are brought by load fluctuations, and studies the treatment program of reactive power problems in the case of load changing. Firstly, achieves the uncertainty modeling of the fluctuation of load power based on historical data of different power users and related theoretical analysis, and obtains the probability density function of the distribution of load power. Secondly, uses two probabilistic calculation methods as Monte Carlo and2PEM that are based on the load probability model to achieve power flow calculation. Through analyzing the expectation and variance of branch power and node voltages, to realizes the reactive power compensation optimal allocation of distribution system with fluctuations load using genetic algorithms, selects the initial position of the reactive power compensation with sensitivity method, on this basis, considers the cost of investment in equipment, the effect of economic governance, the voltage quality and other optimization goals, optimizes the allocation of reactive power compensation capacity.Through the reach above, the paper solves the problems of reactive power optimization under the impact of fluctuations in load power users, makes foundation to further improve the voltage quality and bring economic at the same time. |
