1. Test purpose
2 Test object
1. secondary winding of the transformer.
The voltage ratio of the transformer (referred to as the transformation ratio) is the ratio of the high-voltage winding voltage U1 to the low-voltage winding voltage U2 when the transformer is unloaded,
that is, the change ratio k = U1/ U2. The transformer ratio test is to verify whether the transformer can achieve the specified voltage conversion effect.
A test of whether it meets the technical conditions of the transformer or the values specified in the nameplate.
3. Test Wiring Diagram
4. Test steps
(1) Ground the ratio tester (connect the ground terminal first, then connect the instrument terminal)
(2) Connect ABC and abc of the variable ratio tester with ABC and abc of the transformer through special wires.
(3) Input "transformer group", "total connection number", "step difference" and "rated transformation ratio" on the transformation ratio tester respectively ".
Select "Start Data Measurement", press the "Confirm" key to display the connection method and transformation ratio, and press the Confirm key to measure.
5. Test standard
according to 《 preventive Test Code for Electric Power Equipment DL/T 596-1996 test period:
1) After disassembly and assembly of tap changer lead,
2) After replacing the winding,
3) When necessary. Requirements:
1) The voltage ratio of each corresponding connector shall not be significantly different from the nameplate value and shall conform to the law,
2) The allowable deviation of voltage ratio of transformers with voltage ratio below 35kV and voltage ratio less than 3 is 1%; All other transformers: the allowable deviation of rated tap voltage ratio is 0.5, and the voltage ratio of other tap shall be at the impedance voltage value (%) of the transformer
within 1/10 of, but not more than 1.
Precautions and Frequently Asked Questions
1. Precautions
(1) The phase sequence of the transformer is (neutral point), phase A, B, C. The wiring cannot be reversed.
(2) Pay attention to the input transformer group on the transformation ratio tester to prevent errors.
2. Frequently Asked Questions
(1) Check the instrument setting gear and transformer whether the actual gear is consistent.
(2) Consider whether the tap changer connector position is wrong.
(3) Consider whether the number of turns of the coil is wrong.
Above is introduction of Ancorset Testing Certification to Variable Ratio Test, for reference only, some of the material comes from the Internet and does not represent the point of view of Ancor's detection technology and is responsible for its authenticity. If you are involved in the content of the work, copyright and other issues, please contact us within 30 days, we will delete the content in the first time!
