The Research On3-Phase Hybrid Switch Used In Instantaneous Low Voltage Compensation

With the development of the society, the demands for the stability of power system, reliability of power transmission and distribution and quality of electric energy are gradually increased. So the Uninterrupted Power Supply (UPS) is arose, through the analysis of different UPS’s structures, it can be found that no matter what structure a UPS has, it has to cut off the fault section firstly as the system out of order, then switches the backup power on. So it is necessary to develop a new kind of high speed switch to meet the requirement that cut the fault circuit off when the supply source goes wrong.This paper has proposed a new hybrid switch aimed at the needs of fast operating, it is mainly consisted of a high speed switch and an IGBT module, and it has combined the advantages of the two kinds of switches that will realize no-arc circuit breaking fast, meanwhile, it has overcame the problems that arcing and long operating time when a mechanism switch breaks circuit and the heat produced by thyristor switch.The high speed switch is mainly used in the normal running time, its contactor moving quickly and the initial velocity is high. The structure of actuator is simple and it is connect to the interrupter directly, so the operation efficiency and working reliability is improved significantly. As the hybrid switch is finally used in the3-phase power system, this paper has analyzed the different factors which may effect the3-phase switching synchronous operation, and obtained the impact to the3-phase switching synchronous operation of the different factors.IGBT module is the operative part to switch on or off the circuit without arcing of the hybrid switch. Through the analysis of structure and working characteristic of IGBT module, the snubber circuit form has been designed as RC snubber circuit and the circuit parameters is determined by a lot of simulations and experiments; the driving circuit of IGBT module is made finally.A great deal of experiments of3-phase hybrid switch has been taken at the different power factors to test the operating capabilities and the performance of the snubber absorbing circuit. And it has confirmed that the snubber circuit can nicely protect the IGBT module; the high speed switch can cooperate with IGBT module perfectly, and break the circuit without switching arcing quickly.