A system for detecting a fault in electric power conversion equipment having an input stage and an output stage includes an output voltage sensor positioned within the output stage and configured to generate an output voltage signal; an input current sensor positioned at the input stage and configured to generate an input current signal; and a processor configured to analyze the output voltage signal and the input current signal to determine an occurrence of the fault in the electric power conversion equipment.

A fixture for testing electrical equipment. The fixture may have a tool header shaped to releasably engage the test equipment and a plunger that moves generally linearly between a first position and a second position, the first position engaging the test equipment and the second position releasing the test equipment. In some embodiments the tool is header rotatable relative to the plunger. In some embodiments, the tool header is movable relative to the plunger over at least a range of motion of the plunger.

A fixture for testing electrical equipment. The fixture may have a tool header shaped to releasably engage the test equipment and a plunger that moves generally linearly between a first position and a second position, the first position engaging the test equipment and the second position releasing the test equipment. In some embodiments the tool is header rotatable relative to the plunger. In some embodiments, the tool header is movable relative to the plunger over at least a range of motion of the plunger.

Methods and devices are provide for determining a failure in a potential transformer and identifying a phase of the potential transformer exhibiting failure. The failures may be incipient failures. Detecting the failure may include determining voltage magnitudes and angles; determining phase-errors; determining phase-phase errors; and determining an uncorrelated phase using the phase-phase errors. The devices and methods may provide an alarm or indication of the phase exhibiting the potential transformer failures. Post processing may be performed to optimize the time and amount of provided alarms or indications. The voltage angles and magnitudes may be provided by the potential transformers being monitored.

Methods and devices are provide for determining a failure in a potential transformer and identifying a phase of the potential transformer exhibiting failure. The failures may be incipient failures. Detecting the failure may include determining voltage magnitudes and angles; determining phase-errors; determining phase-phase errors; and determining an uncorrelated phase using the phase-phase errors. The devices and methods may provide an alarm or indication of the phase exhibiting the potential transformer failures. Post processing may be performed to optimize the time and amount of provided alarms or indications. The voltage angles and magnitudes may be provided by the potential transformers being monitored.

An interactive test equipment for quality evaluation of power transformers includes at least a control unit, a test question type module and an operating module. The test question type module includes at least a test set, and each of the at least a test set has a transformer, a voltage value display and a resistance value display. Based on the above design, the voltage value display and the resistance value display of the each of the at least a test set can display a measured voltage value and a measured resistance value of wiring connection of a corresponding transformer. Test subjects can initiate the interactive test equipment and select answers through the operating module, and load questions and determine answers through the control unit. The interactive test equipment is used to authenticate and evaluate a judgment ability of the test subjects in order to ensure safety of a working environment.

An interactive test equipment for quality evaluation of power transformers includes at least a control unit, a test question type module and an operating module. The test question type module includes at least a test set, and each of the at least a test set has a transformer, a voltage value display and a resistance value display. Based on the above design, the voltage value display and the resistance value display of the each of the at least a test set can display a measured voltage value and a measured resistance value of wiring connection of a corresponding transformer. Test subjects can initiate the interactive test equipment and select answers through the operating module, and load questions and determine answers through the control unit. The interactive test equipment is used to authenticate and evaluate a judgment ability of the test subjects in order to ensure safety of a working environment.

A method for analyzing a correlation between rail transit and direct current (DC) magnetic bias of a transformer includes the following steps: A: obtaining a current of a feed cable and a DC magnetic bias current: measuring the feed cable current in rail transit and the DC magnetic bias current of a transformer in a power grid within a certain period by a monitoring apparatus; B: calculating a characteristic quantity of the feed current within the measurement period based on the obtained current of the feed cable; C: calculating a characteristic quantity of the DC magnetic bias current within the measurement period based on the DC magnetic bias current; and D: calculating a support degree and a confidence coefficient based on the calculated characteristic quantity of the feed current and the calculated characteristic quantity of the DC magnetic bias current, and generating a correlation rule.

A method for analyzing a correlation between rail transit and direct current (DC) magnetic bias of a transformer includes the following steps: A: obtaining a current of a feed cable and a DC magnetic bias current: measuring the feed cable current in rail transit and the DC magnetic bias current of a transformer in a power grid within a certain period by a monitoring apparatus; B: calculating a characteristic quantity of the feed current within the measurement period based on the obtained current of the feed cable; C: calculating a characteristic quantity of the DC magnetic bias current within the measurement period based on the DC magnetic bias current; and D: calculating a support degree and a confidence coefficient based on the calculated characteristic quantity of the feed current and the calculated characteristic quantity of the DC magnetic bias current, and generating a correlation rule.

A transformer failure identification and location diagnosis method based on a multi-stage transfer learning theory is provided. Simulation is set up first, a winding parameter of a transformer to be tested is calculated, and a winding equivalent circuit is accordingly built. Different failures are configured for the equivalent circuit, and simulation is performed to obtain a large number of sample data sets. A sweep frequency response test is performed on the transformer to be tested, and detection data sets are obtained. Initial network training is performed on simulation data sets by using the transfer learning method, and the detection data sets are further trained accordingly. A failure support matrix obtained through diagnosis is finally fused. The multi-stage transfer learning theory is provided by the disclosure.