Research On Modeling And H_∞Rubost Control Of STATCOM Based On Switched System

At present, the power system plays a vital role in China’s national economy, therefore,power indicator problem of the system attracting much attention, reactive power and voltageas one of the light elements give enough weight, the stability of the system is not to beneglected, static synchronous compensator (STATCOM) is a member that has high precisioncontrol, fast response time, dynamic reactive compensation ability in flexible exchangetransmission system devices. At the same time, it has become a hot topic in the study ofreactive power compensation devices and a growing number of widely applied to powersystem.From emit and absorb reactive power and inverter bridge circuit structure’s analysis weknow that the process of open and close high-power power electronic components inSTATCOM which have continuous and discrete characteristic, the complex characteristicdevice is difficult to found accurate model. and in the past only did we were limited in linearsystem, actual dynamic physics process always are approximated, so it can’t satisfy to designbetter controller.In view of the above questions, this article proposed robust control based on the theoryof switched system, and combine PWM technology with switching system theory, parallelsingle-phase STATCOM established switching model, and puts forward a complex systemthat it consider a single-phase STATCOM switch mixed characteristics and outsideinterference factors, the equivalent discrete, change the nonlinear questions to linear questionsand solved the problem of nonlinear control calculation, finally it could realize the real-timetracking of the current instruction, restrain the interference. In order to applied the method tothe practical projects, this paper analysis three-phase STATCOM each switch subsystemdynamic performance of the topological model in single PWM cycle, and detailed analysiseach subsystem working condition, thereby establish a more accurate mathematical model ofpopular neighborhood in balance within the approximate linear, finally using robust controltheory to realize the dynamic performance of the system stability control.