Reform Of Voltage/Reactive Power Control System Of Linshui Substation

In the modern power system, load sharp fluctuation causes dispersion of the voltage increased in space and time. It means voltage in some place is excessively high and in another place is excessively low during the same period of time; or the voltage is sometimes high and sometimes low in the same region. Therefore, improving the automatic control system of voltage / reactive power of substation plays an important role in guarantee voltage quality and economic operation of the power supply system.Now, in the most of the domestic substation the means of voltage / reactive power control are changing tap of on-load tap changing transformer and switching shunt compensating capacitors and reactors connecting with 10kV bus or 35kV bus on or off. This control device, named voltage quality controller (VQC), usually uses control method of nine-zone defined by the upper and lower limit of voltage and the upper and lower limit of reactive power. The actual operation aspect indicates that the VQC devices adopting nine-zone control method generally appear abnormal continual operation. It has seriously influenced the service life of executive electrical equipments. Therefore, the VQC devices have been forced to stop using generally. TD-VQC/3 series intelligence voltage / reactive power integrated control devices installed in the most of substation dominated by Guang'an power industry bureau, are also difficult to put into operation because of using the nine-zone control method. It causes the voltage / reactive power control still to be at the manual condition.In order to solve the problem of voltage / reactive power automatic control of substation, Guang'an power industry bureau and Chongqing University cooperate for existing questions of nine-zone control method. It proposes a new control method based on real-time regulating voltage replaces the nine-zone control method for reform of the original voltage / reactive power control system. For the success in reform works, Guang'an power industry bureau takes the Linshui substation as an experimental substation to research reform feasibility and implement scheme of the TD-VQC/3 voltage / reactive power control system. In this thesis, in order for reform works to carry on successfully, it thoroughly analyzes the existing questions of the original voltage / reactive power control system, as well as feasibility of the new control method applied to the Linshui substation. Finally, it analyzes the related questions needed to solve which according to the existing condition to reform the original voltage / reactive power control system.In the thesis, contents are mainly studied as follows:①Based on analysis to TD-VQC/3 device, it shows that the nine-zone control principle counteracts the regulating voltage principle of power system through the theoretical analysis and the measured data. It necessary to get rid of the nine-zone regulating pattern;②Based on real-time regulating voltage calculation, it proposes the control objects and regulating principles of voltage / reactive power control system of substation;③It proposes selection principle of load model and reduce model of power system with real-time regulating voltage calculation;④It analyzes the real-time regulating voltage calculation applied to Linshui substation;⑤It proposes technical ways and implement schemes for reform project of voltage / reactive power control system of Linshui substation.The research results have proven the voltage / reactive power control method of substation is rational which based on the real-time regulating voltage calculation. It is viable to adopt the new method for reform the original voltage / reactive power control system in engineering.