The Study Of Reactive Optimization And Reactive Control In Zhenjiang Electric Power Grid

Voltage is one of main quality factor of electric power,it takes a very important impact on power system stable run. Reactive power has close relationship with voltage quality. To improve voltage quality, increase reactive power division,reduce network losses,reactive power optimizing of powers ystem must be performed. Reactive power optimizing is a complicated Nonlinear Mixed Integer Programming problem. it can achieve the best solution of reactive power distribution under the restriction of keeping the voltage within limits and one electric power factor reached,such as minimum network losses or minimum fare yearly.This thesis summarizes the concept of voltage/reactive control and management,discusses the control variables, feature and method of reactive power optimizing,equality restriction,non-equality restriction,object function and solutions,the ways mainly include non-direct planning,quadratic programming,linear programming,mixed programming,interior programming and AI analysis ways.This thesis applies KKT interior programming to analyze the power grid in Zhengjiang using minimum network losses as object function.The main objectives of reactive/voltage control of regional power grid are to reduce system losses and to improve the voltage profile. In general, there are two main ways in power grid in China: the shunt capacitors and under load tap changer(ULTC) of main transformers, which both contribute to the two objectives above.This thesis discusses a way of a closed loop control system on reactive/voltage control,introduces the structure,control strategy of the control system and application effect in Zhengjiang grid. The control system consists of two parts: the regional-level reactive/voltage control and substation-level reactive/voltage control.This thesis analyze the problem of reactive/voltage control and managemet in Zhenjiang grid based on its run condition,and put forward reasonable solution.