Investigation And Control Of The Voltage Fluctuations And Flicker Problem For The Deng Ta-jian Ji System In Heyuan

With the rapidly development of the national economy, more and more small andmedium-sized steel enterprises have been founded in the city of Heyuan. The impulseReactive Power and Harmonic Current caused by the nonlinear or asymmetric loads injectpower grid constantly, that makes the power system produce power quality problems like amass of voltage fluctuation and flickering, for the high reliability needed users, if thevoltage is not steady,the devices cannot run smoothly. Therefore, analysis and research theinfluence of regional power grid after the access of these steel enterprises have an importantmeaning to standard and promote power quality management.This paper takes JianJi-Dengta line system in Heyuan as the research object,the study areas follows:firstly, the PCC point voltage fluctuation and flickering of Jianji-Dengta linesystem are estimated and analyzed theoretically, and the recent method and strategy ofcontrolling voltage fluctuation and flickering are introduced;then,the operating principle ofparallel STATCOM have been studied in detail,the main circuit structure of STATCOM isintroduced,and its dynamic mathematical model is analyzed,the simulation softwareMATLAB has been used to prove the validity of its principle;To solve the existent defect ofPI controller in STATCOM, the sliding mode variable structure(SMVS) control method hasbeen used to design the voltage regulator,and this makes the system have faster response,good robustness,convenient design and other features.In the last,through a series ofsimulations and experiments,the speed regulation system performances between PI controllerand SMVS controller are compared,the result proves that the designing control system ofSTATCOM based on SMVS theory has advantages of faster response and better robustness.From the practical engineering,this paper takes PCC point voltage fluctuation andflickering of JianJi-Dengta line system in Heyuan as the research object,its controllingstrategy has achieved optimal design based on the primary STATCOM device,and the voltagefluctuation and flickering of Dengta-Jianji can be depressed efficiently,and its self-healingability has been enhanced.