Zc-203c special transformer ratio tester is the third generation of professional transformer ratio testing equipment newly introduced by our company, which can be used for three-phase transformer testing of power system, especially for Z-winding transformer, rectifier transformer and balance transformer testing. The instrument adopts large screen liquid crystal display, Chinese menu and Chinese character printout, with friendly human-computer interface, perfect function and convenient operation, which is in the leading level in China.
Zc-203c special transformer ratio tester is an ideal instrument for transformer ratio, group, polarity and angle test of power system, transformer manufacturer and railway electrical system. What is the test method of transformer ratio? This article is to answer for you.
1、 Test purpose
When the power transformer is handing over and replacing the winding, and after the internal wiring changes, the transformation ratio of all taps of the winding shall be measured.
Under no-load condition, the ratio of voltage U1 of high-voltage winding to voltage U2 of low-voltage winding is called transformation ratio. The transformation ratio of three-phase transformer is usually calculated by line voltage. The purpose of transformer ratio test is to check whether the number of turns of winding is correct, check the condition of tap changer, check whether there is metal short circuit between layers (turns) of winding, etc., so as to provide basis for whether the transformer can be put into operation or parallel operation.
2、 Test method
The transformer ratio test applies voltage on one side of the transformer, measures the voltage on the other side with instruments or instruments, and then calculates the transformer ratio according to the measurement results. The methods to determine the transformation ratio are bridge method, double voltmeter method and standard transformer method.
3、 Analysis and judgment of test results
1. There should be no significant difference between the voltage ratio of each phase connector and the nameplate value, and it should conform to the law.
2. The allowable deviation of the voltage ratio of the transformer with the voltage ratio less than 3 is ± 1% under the voltage of 35kV; the allowable deviation of the rated tap voltage ratio of other transformers is ± 0.5%, and the voltage ratio of other taps shall be within 1 / 10 of the percentage of the transformer impedance voltage value, but not more than ± 1%.
The above is a brief introduction of zc-203c special transformer ratio tester of our company and the transformer ratio test method. Do you understand it? If you have any questions, you can consult our customer service for details.
