A node energy diagnosis method for a fault of a switched reluctance motor double-switch power converter. By detecting a transient value of a phase current of a switched reluctance motor double-switch power converter, a node energy standard deviation σ is calculated to be used as a fault characteristic quantity, and a main switch lower-tube short-circuit fault of the switched reluctance motor double-switch power converter is diagnosed by adopting a node energy standard deviation σ curve of the phase current of the switched reluctance motor double-switch power converter in the whole rotation speed range. It also can be applied in fault diagnosis when a main switch lower-tube short-circuit fault occurs in two phases or more than two phases of a switched reluctance motor double-switch power converter. It is applicable to switched reluctance motor power converters with various phase numbers and a double-switch structure, is durable, reliable in fault diagnosis and good in effect, and has good practicability, and wide application prospect.

A node energy diagnosis method for a fault of a switched reluctance motor double-switch power converter. By detecting a transient value of a phase current of a switched reluctance motor double-switch power converter, a node energy standard deviation σ is calculated to be used as a fault characteristic quantity, and a main switch lower-tube short-circuit fault of the switched reluctance motor double-switch power converter is diagnosed by adopting a node energy standard deviation σ curve of the phase current of the switched reluctance motor double-switch power converter in the whole rotation speed range. It also can be applied in fault diagnosis when a main switch lower-tube short-circuit fault occurs in two phases or more than two phases of a switched reluctance motor double-switch power converter. It is applicable to switched reluctance motor power converters with various phase numbers and a double-switch structure, is durable, reliable in fault diagnosis and good in effect, and has good practicability, and wide application prospect.

Implementations of ground fault circuit interrupter (GFCI) self-test circuits may include: a current transformer coupled to a controller, a silicon controlled rectifier (SCR) test loop coupled to the controller, a ground fault test loop coupled to the controller, and a solenoid coupled to the controller. The SCR test loop may be configured to conduct an SCR self-test during a first half wave portion of a phase and the ground fault test loop may be configured to conduct a ground fault self-test during a second half wave portion of a phase. An SCR may be configured to activate the solenoid to deny power to a load upon one of the SCR self-test or the ground fault self-test being identified as failing.

Implementations of ground fault circuit interrupter (GFCI) self-test circuits may include: a current transformer coupled to a controller, a silicon controlled rectifier (SCR) test loop coupled to the controller, a ground fault test loop coupled to the controller, and a solenoid coupled to the controller. The SCR test loop may be configured to conduct an SCR self-test during a first half wave portion of a phase and the ground fault test loop may be configured to conduct a ground fault self-test during a second half wave portion of a phase. An SCR may be configured to activate the solenoid to deny power to a load upon one of the SCR self-test or the ground fault self-test being identified as failing.

The present disclosure is a transformer monitoring system that has a transformer monitoring device that reads a measurement on at least one node of a transformer. Additionally, the system has a processor that analyzes the measurement and compares the measurement to a threshold value. In addition, the processor transmits an alert to utility personnel if the comparison indicates that the system is not operating properly.

The present disclosure is a transformer monitoring system that has a transformer monitoring device that reads a measurement on at least one node of a transformer. Additionally, the system has a processor that analyzes the measurement and compares the measurement to a threshold value. In addition, the processor transmits an alert to utility personnel if the comparison indicates that the system is not operating properly.

The present disclosure provides an optimization method, a unit, and an electronic device of a shifted frequency (SF)-based electromagnetic transient simulation, comprising: determining a current amplitude and a voltage frequency based on a node voltage and a branch current calculated from a shifted frequency on a basis of a current time step; determining an optimal shifted frequency of the current time step based on the current amplitude and the voltage frequency; and updating the shifted frequency by adopting the optimal shifted frequency of the current time step for calculating a node voltage and a branch current of the next time step. The method, the unit, and the electronic device provided in the present disclosure may gradually update and optimize the shifted frequency in the simulation process so to enable the shifted frequency to reach the best, thus ensuring the accuracy of output current and voltage simulation results.

The present disclosure provides an optimization method, a unit, and an electronic device of a shifted frequency (SF)-based electromagnetic transient simulation, comprising: determining a current amplitude and a voltage frequency based on a node voltage and a branch current calculated from a shifted frequency on a basis of a current time step; determining an optimal shifted frequency of the current time step based on the current amplitude and the voltage frequency; and updating the shifted frequency by adopting the optimal shifted frequency of the current time step for calculating a node voltage and a branch current of the next time step. The method, the unit, and the electronic device provided in the present disclosure may gradually update and optimize the shifted frequency in the simulation process so to enable the shifted frequency to reach the best, thus ensuring the accuracy of output current and voltage simulation results.

An inductor current detecting circuit is provided. A differentiator circuit differentiates a high-side voltage signal to generate a first differential signal, and differentiates a low-side voltage signal to generate a second differential signal. A first current source outputs a first charging current according to the first differential signal. A second current source outputs a second charging current according to the second differential signal. First and second terminals of a first switch are respectively connected to the first current source and a first terminal of a second switch. A second terminal of the second switch is connected to the second current source. Two terminals of a capacitor are connected to the second terminal of the first switch and the second current source respectively. The first switch and the second switch are alternately turned on to obtain a continuous waveform.

A leakage current detection circuit is used for detecting a leakage current, includes a main winding, an auxiliary winding, a detection module and a signal output module used for outputting a pulse signal with pulse signals with positive and negative alternations, wherein the main winding is connected to a leakage current detection end and coupled to the auxiliary winding, and the auxiliary winding is respectively connected to the signal output module and the detection module. During the auxiliary winding in a preset state and a leckage current occurred, the leakage current coupled to the auxiliary winding is superimposed with the pulse signal, so that the current signal detected by the detection module is greater than the current signal detected when the pulse signal with pulse signals with positive and negative alternations is not applied.