The Study Of Voltage And Reactive Power Control Strategy In Power System

Voltage is an important indicator to measure electric energy,which has direct impact on the safety and stability of electrified wire netting.There is a close connection between the voltage and reactive power,and unreasonable distribution of reactive power can not only result in the loss of the network but also affect the quality of the voltage.Keeping the qualified voltage and the reduction of power loss needs to realize the lamination and subarea and local equilibrium of reactive power.Transformer substations are the hub to connect power stations and users.The transformer substations with different voltage levels assume an essential task of voltage and reactive power regulation.Generally,transformer substations mainly depend on shunt compensation capacitors and regulation of load regulation transformers to control reactive power,in order to compensate the local reactive power and regulate voltage and make load side bus voltage maintain in a qualified range and ensure the basic balance of reactive power.The voltage-reactive control has become a necessary and essential measurement to improve the economical efficiency and stability and to ensure the qualification of voltage.This paper discussed the principle of substation voltage reactive power control strategy and introduced a mathematical model of a simple substation and point out the basic goal for controlling the reactive voltage.After compared and analyzed control strategy of nine-zone theory and its improved partition map control strategy and artificial intelligence control strategy and dynamic reactive power compensation strategy,found that five-zone theory control strategy has its unique advantages.This paper describes its operation model,start zone,border control and control demonstrates so on and so forth.At the same time,the influence of the Static Var Compensator(SVC)on the substation voltage reactive power has been introduced.This paper put forward the control strategy which combines the “five-zone theory” control strategy with Static Var Compensator(SVC).Firstly,using the “five-zone theory” to roughly regulate the substation voltage and then taking the advantage of SVC with rapid and precise adjustment ability to conduct voltage reactive power dynamic reactive power compensation and to realize fine-tuning.This paper used a single substation model as an example to simulate the model we proposed in this paper.The analysis result shows that the coordinated control strategy can guarantee the optimal system voltage and minimum network loss.Adopting coordinatedcontrol strategy can track the fluctuation of voltage and reactive power,which results from system load change.Optimization calculation can be conducted online and find the optimal working point under the constraint conditions.The effect of the control strategy we proposed in this paper,which not only make system voltage reactive power run in optimal state,but also can reduce regulating times of load tap changer and capacitor switching frequency so that extend using longevity of devices.