A flexible and temporal integral optimal reactive power control system

Abstract

This paper proposes a flexible and temporal integral voltage/reactive power control system. The voltage stability problem is mainly driven by the dynamics of consumers’ load demand which possesses both daily periodic character and short-term stochastic character. These two aspects are specifically addressed in the proposed system comprising mainly two control components: an optimal planner and an intelligent plan adaptor. The first component, utilizing multi-stage optimal reactive power flow algorithm, can produce a schedule of voltage control actions for the following fixed period. When this predefined plan becomes unsuitable for maintaining an acceptable voltage profile because of unexpected events in real operation, the second component takes over. It synthesises the predefined plan and the current sensitivity information between control actions and voltage profiles. Then it flexibly adjusts the predefined plan to suit the new situation. A simple 9 bus test system is used to demonstrate the application of the proposed approach. This approach works well in controlling the voltage fluctuation of a typical 9-bus system and it can be easily extended to larger practical power systems.