Study Of VAR And Voltage Control In Substation Automation System

Voltage is one of the most important target aims of power quality in power system. Reactive power balance in power system is important condition to ensure the voltage quality. In order to make the voltage reach the prescriptive standard, regulating the change ratio of the transformer and casting or shutting off the reactive power compensation equipments are adopt. The research of voltage regulation and reactive power compensation in substation automation system has very important practice significance.This thesis analyse homely basic theory about VAR and voltage control of electric power system. With the discussion on voltage and reactive power regulation of power system as well as the principle of VAR and voltage power control, the thesis makes a study on the character and principle of voltage and reactive power control, interprets the controlling regularity of substation.At present the margin of upper/lower limit in the control regulation of voltage and reactive power control units is fixed, it have not consider that reactive power compensation impacts on voltage condition and that the adjustment number of the transformer taps switch is excessive relatively. With the consideration of the changes of transformer taps and the combined influence of capacity groups and reactive power and voltage, the thesis makes adjustment suggestion to the different operating-zones of voltage and reactive power. In the maintenance of adjustment number and compensation effect, effectively reduced the adjustment number of the transformer tap switch, and reduced the voltage undulation.The thesis introduces the structure of hardware and software, the hardware adopts 32-bit Motorola CPU and 14-bit AD sample chips, in software optimizes automation function and adds some measure to elevation the stability and reliability. After the design of voltage and reactive power automation, makes a research on the function of integrate in the remote terminal units of substation automation system, also discuss the principle and character and method of VQC in RTU.