The Research Of Voltage And Reactive Power Control Strategy In Substation Based On Coordination Between High Voltage Grid And Low Voltage Grid

The voltage and reactive power control strategy in substation is core of voltage and reactive power control in substation, the design of which can decide whether the controlling effect good or not. Today’s voltage and reactive power control strategy in substation generated when the voltage and reactive power control devices in substation used in power grid before. Since simple grid structure and conventional operation in previous grid, the traditional strategy can satisfy requirements of previous grid. Otherwise, in recent years, with the increasing of the electricity consumption, the increasing of complexity of power grid structure, the widening of peak load and valley load, the extreme operating conditions emerges more and more frequently, such as excessively high or low voltage at certain times. If we also use the traditional strategy, we can’t make use of the reactive resources in low voltage side to improve the voltage/reactive condition in high voltage side. How to make sure the reactive power of high voltage side and voltage of low voltage side be in reasonable range, make full use of the reactive resources in low voltage side, and adapt to needs of extreme operation of upper and lower grid becomes the new target of voltage/reactive control in substation.Based on the problem referred, the mathematical model of voltage and reactive power control devices in substation is built and the effect of action of transformer and reactive power compensation devices is analyzed firstly in this paper. Then, the new strategy called twenty-one-zone theory is proposed based on adding the high voltage side of transformer as criterion to seventeen-zone theory in this paper. For the research needs of controlling process of the voltage and reactive power control devices under different strategies, the software including two functions which is simulation and parameter setting is write by C language The software can simulate the controlling process of the voltage and reactive power control devices in substation under twenty-one-zone theory or seventeen-zone theory. It also can set the reactive parameter of twenty-one-zone theory or seventeen-zone theory. At last, we use the software to simulate two poor controlling phenomenon under seventeen-zone theory by twenty-one-zone theory. We also simulate the controlling process on one substation of a day. The simulation results show that the new voltage and reactive power control strategy in substation can make full use of the reactive resources in low voltage side to achieve the coordination between upper and lower grid and it has important engineering value and practical significance. It also shows that the parameter setting is efficacious and the software runs stably and has good effect.