The Study Of Characteristics On Vacuum On-Load Tap-Changer

In power system, voltage is one of the important indicator of quality. While the power system working during normal operation, the voltage fluctuation will make the utilization equipments abnormal which influence on production and daily life.Load-ratio voltage regulation of transformer is the voltage regulation, which has larger regulation scope and less investment and higher speed and well effect in power-conditions. The regulation scope is 15% or more. It can also be regulated in real time, manual-action control and electromotive control and remote electromotive control can also be selected which is convenient to the realization of automatic management.On-load tap-changer is the main device of the transformer to connect to the high-voltage tap .In the transformer with a load state, the vacuum on-load tap-changer signals from the controller to automatically switch tap position to change between high and low voltage winding turns ratio, so as to achieve stable or adjustable load center voltage, improving system and reduce reactive loss of effective measures. Currently, the reliability of mechanical life is improved, which is increased from 0.2 million to 0.5 million times, or even 1 million times. Electric life is from 20 thousand to 5 thousand. The relative failure rate is less than 1.5～2.0%.This paper by comparing the vacuum on-load tap-changer and ordinary on-load tap-changer about mechanical reliability illustrates the vacuum load tap-mechanical reliability. On the based of PYFIII400D/10-9 vacuum load tap, the style of single resistor and non-symmetrical switch can be met by comparing few switching circuit. The way can save the greatest degree of cost. The voltage rating of the switch is 10 kV, applicable to the exchange of 50Hz. The lateral line voltage is10kV, rated current of 400A.It is equipped with oil-immersed transformers. Through the DC light oscilloscope, we can see the switch timing of the main tap, the main transition tap, the main vacuum interrupter, the vice transition tap and the vice vacuum interrupter. By building the circuit model with Simulink, we can observe the transition resistance on the short-circuit waveform whether there is renewed phenomenon. Finally, the simulation results are compared with the results of type tests. The results proved that the switch used to the switch structure can meet the national standards, which has reliable operation, as well as the switch can directly lift core. It plays a great role on the troubleshooting and equipment maintenance. The development prospection is broad.