Development Of Transformer Economic Operation Control And Flexible Switching Device

The electric energy loss caused by transformer running can reach 30% of the total electric energy in the whole electric energy transmission process.The device can keep transformer unit work in economic state through the reasonable switching operation.Device add the transformer softly switching mode for guaranteeing the switching operation safe.Device execute the switching operation in the time that the voltage and current in power grid values zero,so the impact to the power grid will be reduced in maximum extend.Device hardware consist of electric parameter collection mode,load power detection mode,soft switching mode,contactor switching time detection mode,data access mode,and human computer interaction modular.Software programmed based on hardware modular.The operation of transformer switching on voltage and current zero-crossing point,which related to flexible switching technology,required to predict the AC contactor switching time.So processor could implement AC contactor switching action in advance.Using AC contactor supply voltage and ambient temperature based on bilinear interpolation method to predict AC contactor forecasting switching time.Experiment results shows that at the-20 ? to 40 ? ambient temperature,190 V to 240 V supply voltage,when the ambient temperature is fixed,AC contactor closing time decreases with supply voltage increasing,opening time increases with supply voltage decreasing.When the supply voltage is fixed,AC contactor closing and opening time increases with ambient temperature decreasing.Particularly,AC contactor switching time in 0? to 5? range is minimum.The real experiment ambient temperature is about 25? to 30?,and the supply voltage changes in range.The result shows AC contactor closing time changes like quadratic parabolic partial diminishing,opening time changes like quadratic parabolic partial increasing with supply voltage decreasing.Experiment shows transformer switches on voltage and current zero-crossing point can eliminate the impact of transformer switching in power gird.The accuracy of Transformer switching correctly is 96.8%,the error value of transformer switchingon voltage and current zero-crossing is 3.5%.Finally transformer economic operation analysis of 500 kV substation's load data in Zhejiang shows the equipment can make significant economic benefits.