Substation Voltage And Reactive Power Integrated Automatic Control

The voltage is one of the primary indexes for electric energy quality and the reactive power is an important factor that affects the voltage quality. So voltage and reactive power integrated control in substations is significant for improving the voltage quality, reducing the power loss, ensuring the system safe, reliable and economic.The present situation for voltage and reactive power control in substations is introduced in this paper. The relationship of voltage and reactive power is expounded. And the principle of the automatic regulation of the reactive power and voltage in substations is analyzed and investigated. Based on the discussion of the control strategy formerly used, the disadvantage of actual control strategy is analyzed, and a new kind of control strategy is proposed, which increases diagram of nine zones to thirteen zones. On the basis of the principle of the diagram of thirteen zones of manner, controls over the position of switch of sub-terminals of main transformer and the manner of the switch of compensating capacitors are realized. By minimum the number of operating strokes it urges the position of the sub-terminals of the main transformer and the feature of the switch of compensating capacitors entering into the zeroth district. As a result, the oscillation and the frequent operation of changing position of the sub-terminals of the main transformer and of the switching on and off of capacitor for compensating reactive power are avoided. The stability in operation of the integrated control system against reactive voltage of the substation is ensured.On the basis of the control strategy, the paper carries out the investigation for hardware and software. The hardware configuration is composed of six parts, which are SCM system, signal measure part, output control part, the position of the sub-terminals and the state of the switch of capacitor feedback part, display and keyboard input part and communication part. Software comprises A/D sampling using SCM, computing, display, input and output, communication. According to the control strategy, voltage and reactive power integrated regulation and control are realized.Finally, voltage and reactive power integrated control is achieved well through the research. From the operation, the thirteen zones voltage and reactive power control system is better than the typical one, and the power lossâ–³P drop obviously. Furthermore, the paper presents several problems existing yet and the suggestions to solve these problems, puts forward a research direction in the future.