* Question
| What are the methods of current transformer ratio test? |
* Answer
| The current transformer is a special transformer specially used for transforming current. Under normal working conditions, the secondary current is substantially proportional to the primary current, and when the connection direction is correct, the phase difference of the secondary current to the primary current is close.At zero.The current transformer field ratio test generally adopts the current method. The current method is used to measure the current transformer ratio. Actually, it is the actual operating condition under the condition of rated current. It is an ideal test method with high measurement accuracy.However, with the continuous development of the power system, the capacity of a single generator is getting larger and larger.For example, a 800 MW generator set with a rated voltage of 20 kV and a rated current of 800/(20×3 1/2)=23.094 kA, the corresponding current transformer has a large primary current. If the current method is used to measure the primary current to several tens of amps.The current transformer ratio is difficult to achieve in the field: First,Therefore, the method of measuring the current transformer ratio by the current method is increasingly restricted at the construction site.On the basis of the current method, the author introduces another test method for the current transformer ratio – the voltage method.The method is suitable for testing the current transformer ratio at the construction site. |
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