Research On The STATCOM+TSC Hybrid Var Compensation System

Electric energy, which represents the development level of a country, is an importantenergy of modern society. In recent years, the energy shortage and environmentaldegradation problems are becoming more and more serious, energy-saving emissionreduction is highly valued. How to reduce the loss of electric energy and to achieve energyefficiently, has become the focus of research. At the same time, along with the developmentof the society, people’s demand for power quality becomes more and more strict. Reactivepower, which affects the power system stability and economic operation, is an importantfactor of AC power system. Develop dynamic reactive power compensation technology hasimportant practical significance, for that dynamic reactive power compensation is one ofthe most effective means to reduce line losses and improve power quality.Static Synchronous Compensator (STATCOM) and Thyristor Switched Capacitor(TSC) are two kinds of important dynamic var compensator in power system. This paperpresented a STATCOM+TSC hybrid var compensation system, using STATCOM’s smoothand fast regulation performance combined with TSC’s simple structure, low cost. It can notonly guarantee the overall dynamic performance, but also reduces the overall cost.This paper introduced the principle and structure of the STATCOM unit and the TSCunit, respectively. At the same time, this paper also established a mathematical model forSTATCOM unit and put forward the ameliorative method for TSC triggering shock.This paper presented a coordinated control strategy for the STATCOM+TSC hybridvar compensation system. The TSC is used to meet the majority demand of reactive power,while the STATCOM is used to deal with the dynamic demand of reactive power. Thedetailed design of STATCOM+TSC hardware and software part was presented, twoSTATCOM actual device were produced, and the field tests were carried out, and achievedgood results; At the same time, a STATCOM+TSC prototype was made, some relevantexperiments were conducted on the prototype and the experimental results were presentedverifying the design and the control strategy.