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

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 previous 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 had a thorough research on voltage and reactive power of the system power network by means of calculation,analysis and experiments. And a solve scheme was presented and implemented,controlling the voltage of 220kV power network in Chongqing under 232kV during low load period. A main network calculating equivalence model of power network in Chongqing was constructed. And reactive power optimizing calculation was figured out on the Chongqing power network on condition that the loss minimum of the active power network was object function. Several optimizing compensatory schemes were put forward. Based on the calculation result and the analysis of all schemes,the most reasonable and feasible optimizing scheme could be achieved. Meanwhile,the feasibility that the system voltage could be adjusted when generator operating under excitation was demonstrated. According to the experience of under-excitation operation of the same type units and the suggestion of manufacturers,the generator excitation system was improved to ensure stable function of auto voltage adjusting device during over- excitation and under-excitation operation. The experiment of under-excitation operation and adjusting voltage of generator was carried through in Chongqing electrical power plant. Based on the result,a thorough analysis was taken on the step-down effect,stable limitation,capability of absorbing reactive power when generator operating under excitation. And a P,Q function curve of generator was drawn,which could be used as a foundation of generator operating under excitation.