When purchasing a transformer winding deformation tester, it is common to encounter unclear understanding of the frequency response measurement principle and parameter specifications. The following outlines several common questions from a procurement perspective to help verify technical key points.
1. What does the frequency response method measure? Under the action of a relatively high-frequency voltage, each winding of a transformer can be equivalent to a passive linear two-port network composed of distributed resistance, inductance (mutual inductance), and capacitance, whose internal characteristics are described by the transfer function H(jω). After the winding deforms, the network parameters change, and the frequency response curve shifts accordingly. The tester determines the winding condition by scanning frequencies and comparing curves. During procurement, attention should be paid to the frequency range, number of sweep points, and curve repeatability indicators.
2. Is three-phase automatic testing necessary? During on-site batch testing, manual phase-by-phase wiring is relatively inefficient. Models with three-phase automatic switching capability can reduce wiring operations and lower human errors. Before procurement, it is necessary to confirm the channel switching method of automatic testing, the number of phases that can be covered by a single wiring setup, and whether automatic comparison with historical curves is supported.
3. How to balance sensitivity and anti-interference? Higher detection sensitivity helps identify slight deformation, but on-site electromagnetic interference may affect curve quality. Attention should be paid to whether the instrument has repeatable test consistency, grounding method requirements, and signal filtering settings. Parameter configuration and interface forms can be confirmed according to actual project requirements, and decisions should not be made based solely on a single sensitivity indicator.
4. Do interfaces and data management match? During procurement, verify the tester's output interface types, whether data export and curve archiving are supported, and the software's comparison function for historical data. For units that need to incorporate condition-based maintenance management, data format compatibility and report generation capability should be included in the checklist.
5. Are on-site usage conditions met? Confirm the instrument's operating power supply, volume and weight, bushing types compatible with wiring clamps, and whether battery power supply is supported. For mobile operation scenarios within substations, portability and wiring reliability directly affect detection efficiency.
