Based On The "Five Zones" Fuzzy Control For Substation Voltage And Reactive Power

Voltage is an important indicator in measuring power quality, the quality of the voltage is directly related to security and stability of the grid, therefore ensuring the voltage qualified is an important condition for power system supply with security and high quality. The voltage is related with reactive power closely, the reactive power is an important factor in affecting the voltage value, is also an important reason in causing network wastage, the important mean to reduce power consumption and keep voltage qualified is to achieve the reactive power stratified, zoning, on-site balance.The objective of voltage reactive-power integrated control is in order to improve the grid safety and economical efficiency, During the guarantee voltage quality,decrease network wastage,improving operational efficiency, and can reserve plenty of reactive margin to deal with emergency accident, in order to maintain the security and stability of the power system. Therefore, various substations bear the important task that is to adjust the voltage and reactive power. The voltage reactive power integrated control of substation is to utilize the OLTC and parallel compensation capacitor, to adjust topical voltage and reactive compensation, to ensure the bus voltage of the load side in provisions range, and the primary side power factor of the transformer is as possible as close to 1.From the angle of control theory, the voltage and reactive power integrated control of substation is an optimal control problem that is multi-limit and multi-objective; the electrical parameters in power grid are mutual restriction, the coupling relationship between the transformer tap adjustment and parallel compensation capacitor switching with voltage and reactive power is relative complex, there is certain difficulty in coordinating their actions, therefore, the voltage and reactive power integrated control strategy that whether improving or not is very important to the control effect.The paper discusses the voltage and reactive power integrated control principle, gives the mathematical model, points out the basic control objective of the voltage and reactive power integrated control. Mainly analyze the operational model of the "five zones" control strategy,the borders of the control,the action areas,the blind areas and so on, propose a new method that using fuzzy control theory control the voltage and reactive control of the substation on the basis of the "five zones" control strategy.First introduces the basic principles of fuzzy control, analyzes and designs the reactive power fuzzy controller model of substation, and analyzes the various modules of the model. Through fuzzy region partition to the "five zones" control strategy, using the judgment that is based on the criterion of the operation merit distance of the "five zones" control strategy to judge the regional action strategy, and as the fuzzy control rules of the fuzzy controller. Second, the analysis of fuzzy control rules, not difficult to find:Using the "five zones" control strategy to control the substation can effectively improve the situation of substation voltage and reactive power operation.Finally, using voltage and reactive power fuzzy control that based on the "five zones" control strategy to simulate the substation. Through the analysis of the different fuzzy membership function of the simulation results, not difficult to find:the fuzzy membership function have impact on the simulation results, but the basic trend is the same, contrast the voltage and reactive power fuzzy control that based on the "five zones" control strategy with the improving "nine zones" control strategy, can effectively reduce the Action times of equipment, Improve the voltage quality and reactive power distribution.