The voltage transformer is a common electrical equipment in the power system, and it is also one of the important power voltage conversion equipment. In the daily maintenance of the transformer, in addition to the partial discharge detection, it is also necessary to detect the reliability of the transformer winding welding and the winding Whether there is a short circuit, whether the tap switch is good, whether the wire is broken, etc., these problems can be reflected by the DC resistance of the transformer winding.

In order to meet the needs of transformer DC resistance measurement, our company has developed a DC resistance tachometer. The instrument adopts brand-new technology and has the characteristics of high efficiency, small size, light weight, and large output current. When testing the DC resistance of the transformer, you need to pay attention to measuring the no-load tapping transformer, you must wait for the discharge prompt to end, then switch the transformer gear, and after the test is completed, you must wait for the discharge indicator to complete, then turn off the power and remove the test In general, if an inter-turn short circuit occurs in a certain phase of the transformer, the DC resistance of that phase will decrease. If the welding is poor or broken, the DC resistance of the phase will increase. The tap switch fault depends on the fault type. When the test result is abnormal, a comprehensive analysis should be carried out first, compared with the data of previous years to eliminate interference, and combined with other insulation supervision tests, so as to make a more accurate and reliable judgment on the type of fault and the location of the fault.