Study On Reactive Power And Voltage Optimization In ChongQing Electric Power Network

Reactive power optimization of power network is an important problem which directly influences voltage quality of the system as well as which relates to economical operation of power network. During the calculation of reactive power and voltage in the power network, reactive power insufficiency and the system under-voltage are always concerned. In the same way, we should consider the problem that reactive power surplus and over-voltage during the period of low-water and low load. According to the problem of over-voltage in Chongqing power network during the low load period, this paper has a study on voltage and reactive power of the system power network. And a solve scheme is presented, controlling the voltage of 220kV power network in Chongqing under 232kV during low load period.With the increase of load and power supply, the reasonable positions and capacitance of reactive power compensation become reasonless. While with the super hige voltage power network gradually built and the structure of system becoming more complex, the calculation time of optimization increases when the number of buses that need reactive power compensation is relatively large. Especially, when the positions of compensation are uncertain, selecting the position of compensation can reduce time when reactive power optimizing. This paper firstly analyses the positions of reactive power compensation before reactive power and voltage optimization. Considering the properties of reactive power compensation, the paper synthetically analyses and compares the methods of sensitivity analyses, singularity analyses margins analyses and modal analyses, and draws a conclusion that the modal analyses based on sensitivity is more practical and effective for selecting the positions of compensation. The method has properties of explicit concept, small computation and rapid processing, and is suitable for the selection of the positions of compensation in great scale power system.This paper calculates and analyses the positions of compensation in Chongqing power network respectively by means of sensitivity analyses singularity analyses margins analyses and modal analyses. Before optimization, the paper firstly makes certain the weak voltage bus and the positions of compensation. Then reactive power optimizing calculation is figured out on the Chongqing power network on condition that the loss minimum of the active power network is object function, taking account of the limit of voltage restriction condition, adopting three mode of generators adjustment reactive power compensation and tap change. It achieves satisfaction result, expectable purposes of reducing voltage and active loss. The result provides efficiency decision-making basis for the operation mode of Chongqing power network during low load period, and has important economic and social benefits.