Short-term Transmission System Reactive Power Law Analysis And Research

The analysis of reactive power variation cycle in power system is the basic work to realize automatic Voltage Control (AVC). The voltage and reactive power control can be centralized and cooperated by AVC. Based on this, the voltage quality, the loss of the system operation, as well as the distribution and utilization of reactive power resource can be optimized in effect. However, it is hard to do it once the reactive power variation cycle can not be forecasted looking ahead.The reactive power variation cycle should be analyzed from each bus, which can be obtained with the relations among active and reactive power, the reactive power static state characteristic. Therefore, as long as the variation cycle of reactive power and voltage for every bus can be forecasted accurately, it is very important for AVC, and it yet has looking ahead ability. At the same time, the loss of system operation is reduced, the switching times of control devices can be reduced and the equipments participating in real time control are decreased as possible.On this background, by studying power network of certain province, the whole frame for the forecast of the node reactive variation cycle in short time is presented in this paper based on the stabilization analysis of load cycle in frequency field and of the relationship among active and reactive power and power factor and of variation cycle of relationship between the whole and individual. Using the improved BP algorithm and mature time series analysis technology. On the base of forecasting total active power load of the whole nets, it is indirectly analyzed on the node's load active power variation cycle, power factor variation cycle, reactive voltage static characteristic, and the forecast of variation cycle of the node reactive power is carried out. On the aspect of algorithm, in order to improve the forecast effect and the accuracy and speed of thealgorithmic, on the base of expounding the mechanism and characteristic of the modified BP algorithm and the technology of time series in the second chapter, considering the difficulty of the single BP algorithmic for solving the complicated problems, this paper combines the BP algorithmic with other more effect methods in the nonlinear optimization theory, and upgrades the capability of BP algorithm.In this paper, the tentative study is done, and the relevant program is designed. It is proved effectively by applying in the practical power system.