An abnormality detection device for a grid interconnection relay to detect an abnormality of the grid interconnection relay upon switching to grid independent operation, and includes an abnormality detector to execute commercial power system voltage determination of determining whether or not there is a commercial power system voltage, and first voltage determination to be executed if it is determined that there is no commercial power system voltage through the commercial power system voltage determination, of causing the power conditioner to chronologically alternately output monitor voltages having different values in a state where a contact of the grid interconnection relay is controlled to open and executing abnormality determination as to the grid interconnection relay according to whether or not each of the monitor voltages is followed by difference between a voltage of the power conditioner and voltage of the commercial power system with respect to corresponding one of the monitor voltages.

A diagnostic method of switchgear and a device of switchgear that allow regularly grasping a state with high accuracy with a simple configuration is provided. The diagnostic method of switchgear includes: obtaining signals from an acceleration sensor mounted to a switchgear and a load current flowing through the switchgear; determining a frequency to be focused from a spectrum analysis result of the signals from the acceleration sensor in an advance preparation phase of diagnosis of the switchgear, generating learning data using at least the frequency and the load current as feature values; and regularly diagnosing the state of the switchgear from the feature values obtained during diagnosis and the learning data during the diagnosis of the switchgear.

A closed and open contact method to predict a usable life of vacuum interrupters in the field can include using computer instructions in the data storage to instruct the processor to position a calculated amp or calculated pressure on an ionic or current versus pressure calibration curve for the installed vacuum interrupter and identify trend data from a library of trend data corresponding to the installed vacuum interrupter and to the calculated pressure or calculated amp of the installed vacuum interrupter; thereby determining the anticipated life expectancy.

The present invention relates to a solid testing platform and method for function testing of an intelligent phase-change switch. The testing platform includes a primary controller, a first module, a second module, a capacitor C, an intelligent phase-change switch, and a transformer. The primary controller is respectively connected to the first module and the second module, and is configured to control the operation of the first module and the second module. The first module and the second module are connected in parallel to the capacitor C. the first module is configured to feed back excess energy of the capacitor C to a distribution network. The second module is configured to control magnitude and direction of a current that flows through the intelligent phase-change switch. The capacitor C is configured to perform energy support, filtering, and smoothing. According to the present invention, not only all unbalanced operation conditions can be simulated, but also simulated power is equitably fed back to a power grid by using the testing platform, to achieve a test in a state of no power loss, without affecting a main power grid.

A permanently installed absence of voltage tester (AVT) may include a connectivity verification system for verifying the connectivity of system cable leads to the main power lines in electrical equipment. An installed AVT may indicate whether the electrical equipment is in an electrically safe state without first requiring direct access to the equipment. One step in the AVT test procedure may include connectivity verification by the connectivity verification system, which may include a sub-procedure to confirm that the installed AVT is directly coupled as intended with direct connection to the equipment being monitored. The connectivity verification system may validate that the AVT is measuring the actual voltage on the power lines of the electrical equipment and has not registered a no-voltage condition due to an unknown disconnection error or installation failure.

A contact measurement system for measuring a parameter of a contact of a switchgear includes: a first device for measuring an electrical resistance of the contact and mapping the electrical resistance spatially and/or dynamically; a second device for measuring an axial force of the contact and to map the axial force spatially and/or dynamically as a measured axial force; and a third device for measuring a position of the contact. The contact measurement system determines a position-depending force characteristic based on the measured axial force of the contact and the position of the contact. The contact measurement system determines a status of the contact based on a combination of the position-depending force characteristic with the electrical resistance of the contact.

A relay diagnosis circuit capable of diagnosing whether a relay connected to a negative electrode of a battery pack normally operates using voltage applied from a positive electrode of the battery pack.

A method is for testing the functionality of a switching member including at least one switching element. A switching state is influenced via a control input of the switching element and via a control signal generated and output to the control input. An activation signal is output to the control unit and changes the control signal. The activation signal induces a test signal as the change to the control signal and induces a disconnection pulse as the test signal. The SiC or GaN power semiconductor is switched off via the disconnection pulse and conducts current in the reverse direction. In response to the disconnection pulse, the voltage drop is recorded. A comparison is carried out between an indicator and a reference encoding an expected response to the disconnection pulse. Depending on the result of the comparison, a status signal is generated which encodes the functionality of the switching member.

An apparatus includes a safety fault interrupter circuit. The safety fault interrupter circuit includes a safety fault monitor coupled to a first bias node and configured to selectively assert a fault interrupter signal based at least in part on a first bias voltage and a first power consumption. The safety fault interrupter circuit also includes a power fault monitor for the safety fault monitor, wherein the power fault monitor is coupled to a second bias node and is configured to selectively assert the fault interrupter signal based at least in part on a second bias voltage and a second power consumption that is less than the first power consumption.

A modular multilevel converter system, and a voltage detection method and an open-circuit fault diagnosis method thereof are disclosed. The modular multilevel converter system includes: N sub-modules sequentially cascaded, where N is an integer greater than or equal to 2, each of the sub-modules comprising at least one bridge arm and a capacitor connected in parallel to the bridge arm, the capacitor having a positive terminal and a negative terminal; and a voltage detection unit for detecting a voltage between at least two adjacent sub-modules in the N sub-modules, the voltage detection unit being connected between the positive terminal of the capacitor of the first sub-module and the negative terminal of the capacitor of the last sub-module in the at least two sub-modules.