Design And Implement Of The Synchronization Switch For 10KV Capacitor

Deterioration of local voltage fluctuation and power factor caused by changes in power system parameters and load fluctuation would seriously affect power quality and service life of control equipments. There are many inductive loads which should be compensated in distribution network. Otherwise the inductive loads would cause deterioration of the voltage quality and increasing of network loss. As an important reactive power compensation method, parallel capacitor compensation plays an important role in voltage regulation and power factor regulation of power system. But the random switching process of the capacitor group would produce over-voltage, inrush current and restrike of arc in a breaker. The process could damage insulation of electrical equipments, security operation of power system as well as affect performance of higher sensitive devices in supply circuit. Therefore, it can effectively inhibit phenomena of over-voltage, inrush current and restrike of arc by adopting synchronization switching technology.This paper designed and developed a synchronization switching device for 10KV capacitor group based on DSP2812. When it is short of capacitve reactive power in power system and there is a dropping of voltage in a bus, by measuring bus voltage and capacitive reactive power, the device can switches capacitor group automatically and launches the capacitor group in zero-point of every phase voltage to inhabit inrush current. When voltage in a bus is higher than a desired value, the device can cut the capacitor group automatically in zero-point of every phase current to inhabit over-voltage and restrike of arc.After finishing the design and assembling of the synchronization switching device, it was sent to Ketop laboratory for type testing for testing and verifying performance and reliability about the device.This paper also designed and developed the reactive power detection module and touch screen module, and finished the type selection of relay protection, capacitor and reactor, etc. At last, the complete set of reactive power compensation was produced. Field experiment was conducted in 10KV substation of Kai Yuan power plant in Mian Yang city.The field experiment has been carried out for four months. The experiment indicates that the device designed by this paper can run reliably and can effectively inhibit over-voltage, inrush current. Now the device has been applied to the batch production.