Why should it be confirmed first whether the test current can cover the on-site capacity when measuring winding deformation by the low-voltage short-circuit impedance method? Transformer capacities vary widely, and under low voltage the impedance value changes noticeably with current; insufficient range will directly affect the credibility of comparison results. The DRB-6300 transformer winding deformation tester is designed around this issue, with a current measurement range covering AC 10V–600V, suitable for on-site testing of distribution transformers and some power transformers.
During transformer handover acceptance and preventive testing, the tester applies a test voltage on the low-voltage side according to the low-voltage short-circuit impedance method, measures the short-circuit impedance value, and compares it with the nameplate value or historical data. The judgment criteria are relatively clear, usually using an impedance change rate of ±3% as a warning value, making it convenient for technical engineers to quickly give preliminary conclusions on site.
After a transformer experiences a near-zone short-circuit impact, the winding may undergo axial or radial dimensional changes. Through lateral comparison of short-circuit impedance values, the tester can make an indirect judgment of the winding's geometric state. This method has strong anti-interference capability and is suitable for use in substations with relatively complex electromagnetic environments; its sensitivity to slight deformation is inferior to that of the frequency response method, so it should be used in combination with frequency response method equipment.
Short-circuit impedance values are comparable among transformers of the same batch and specification. The tester can measure and record data unit by unit to form a ledger, making it convenient for engineers to conduct lateral comparisons before and after commissioning and identify individuals that deviate from the group value.
After transformer cover-lifting maintenance, winding compaction, or lead adjustment, short-circuit impedance values can be used to verify whether the winding condition has changed. The tester provides stable low-voltage measurement conditions, and the measurement results can be retained as baseline data for subsequent comparison.
Current measurement range AC 10V–600V; testing is based on the low-voltage short-circuit impedance method, and before measurement it should be confirmed that the wiring mode is consistent with the nameplate parameters; test data are recommended to be archived in the same table as the historical ledger to reduce misjudgments caused by different conversion calibers. The equipment is suitable for both substation on-site and maintenance workshop environments.
