Research On Voltage And Reactive Power Control And Application In Shizuishan Substation

The voltage not only concer the electricity quality that support to the consumers, but also affect the safety and economy of the power system. Improve power quality, reduce network losses and ensure power system stability, security and economic operation is of great significance by adjusting the control system voltage and reactive power flow to achieve a reasonable balance of the integrated voltage and reactive power control. Voltage and reactive power control of substation is optimization problem of many limits and many targets. Its math model is complex. Fuzzy control don't need math model and based on language experience, so it can solve control problem of complex system.In most substations, nine-zone algorithm is used as control theory. The relationship of voltage and reactive power is ignored in nine-zone algorithm. The OLTC and breaker will switch much more when using nine-zone algorithm. This paper designed a fuzzy voltage and reactive power control system. The fuzzy control system makes a fuzzy partition on the V-Q plane, through this way the oscillation on the V-Q plane is resolved. The result shows that the OLTC and breaker will switch much fewer by fuzzy control algorithm than by nine-zone algorithm.The paper made a more in-depth and comprehensive analysis of the integrated control of voltage and reactive power (VQC), the following tasks are done:(1)The voltage and reactive power control strategy research is comprehensively expounded in substation at home and abroad, and compared the advantage and disadvantage of the various existing control way.(2) The substation voltage/var control characteristic is represented, and the principle of substation voltage/var controlling is analyzed, the problem of Nine-zone voltage/var control strategy is analyzed in theory.(3)The power grid load characteristics of Shizuishan areas is analyzed, and based on this, fuzzy controller is designed, a tap work and capacitor switching fuzzy control table is derived, and simulation is made for a fuzzy control system, simulation results show that the fuzzy control system can reduce the transformer and capacitors group tap number of moves under ensuring voltage passes, the basic balance of reactive power. (4) According to Yanwochi traditional substation voltage and reactive power control deficiencies. The practical application of VQC device based on fuzzy control is completed in the substation; the technical effect is analyzed after the VQC device based on fuzzy control is applied in Yanwochi substation. The actual operation at the scene proved the correctness of this work.