A method for identifying element failure in capacitor banks is provided. Capacitor bank phase current is measured and a zero-sequence or negative-sequence current is calculated or measured. A three-phase voltage is measured from a three-phase bus voltage transformer and a zero-sequence voltage or negative-sequence voltage is calculated. A compensated unbalance current is calculated and compared to a predetermined acceptable range. A failure is identified where the compensated unbalance current is outside the predetermined acceptable range.

The disclosure discloses a method and device for monitoring partial discharge. The monitoring method including: step a, connecting a monitoring circuit in parallel to both ends of a tested product, disposing a ground wire between the monitoring circuit and ground, disposing a first sensor in the monitoring circuit, and disposing a ground wire sensor on the ground wire; step b, applying an excitation signal to the tested product, acquiring a first signal through the first sensor and acquiring a ground wire signal through the ground wire sensor within a monitoring cycle; and step c, determining whether the tested product has partial discharge through the first signal and the ground wire signal. The disclosure can avoid the partial discharge monitoring device from wrongly determining an interference signal to be a partial discharge signal, enhance anti-interference capability of the partial discharge monitoring device, and improve monitoring accuracy.

The present invention relates to a method for diagnosing the state of the capacitor in a modular converter. The method for diagnosing the state of the capacitor in a modular converter includes determining a FIT table depending on the input voltage and temperature of an internal capacitor for multiple sample modular converters; detecting, by an input voltage detection unit, the input voltage of the capacitor in a target modular converter, the state of the capacitor of which is to be diagnosed, during a preset period; detecting, by a temperature detection unit, the temperature of the capacitor of the target modular converter during the preset period; calculating the cumulative mean for the input voltage and the temperature, which are respectively detected by the input voltage detection unit and the temperature detection unit during the preset period; and selecting, by a control unit, a FIT value corresponding to the cumulative mean of the input voltage and the temperature, from the FIT table; and extracting the MTBF of the capacitor from the FIT table.

A method can be used for testing a charge-retention circuit for measurement of a time interval having a storage capacitor coupled between a first biasing terminal and a floating node, and a discharge element coupled between the floating node and a reference terminal. The discharge element is configured to implement discharge of a charge stored in the storage capacitor by leakage through a corresponding dielectric. The method includes biasing the floating node at a reading voltage, detecting a biasing value of the reading voltage, implementing an operation of integration of the discharge current in the discharge element with the reading voltage kept constant at the biasing value, and determining an effective resistance value of the discharge element as a function of the operation of integration.

A monitoring system includes a capacitor can having one or more capacitors. The monitoring system includes an antenna. The monitoring system includes at least one sensor disposed within the capacitor can and configured to detect an operating characteristic associated with health of the one or more capacitors of the capacitor can. The monitoring system includes a processor configured to receive a first signal from the at least one sensor indicative of the operating characteristic. The processor is configured to send a second signal, via the antenna, indicative of a value of the operating characteristic to a receiving device outside of the capacitor can.

A method includes processes of (a processing part 8) calculating an estimated heat generation temperature by using drive conditions (22, a storage part 6) at least including drive timing information (18) and drive current value information (20), and temperature change characteristic information (24) of a capacitor, calculating state change information (28) of the capacitor after elapse of a reference time by using the estimated heat generation temperature, and calculating a lifespan estimation value (lifespan estimation result 30) of the capacitor by using the state change information. This enables capacitor lifespan estimation corresponding to fluctuations of a drive current value flowing through the capacitor, the applicability of the capacitor is confirmed, and the safety of equipment using the capacitor is improved.

A method includes processes of (a processing part 8) calculating an estimated heat generation temperature by using drive conditions (22, a storage part 6) at least including drive timing information (18) and drive current value information (20), and temperature change characteristic information (24) of a capacitor, calculating state change information (28) of the capacitor after elapse of a reference time by using the estimated heat generation temperature, and calculating a lifespan estimation value (lifespan estimation result 30) of the capacitor by using the state change information. This enables capacitor lifespan estimation corresponding to fluctuations of a drive current value flowing through the capacitor, the applicability of the capacitor is confirmed, and the safety of equipment using the capacitor is improved.

A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

The present description concerns a circuit (5) for monitoring the operation of a component (1) associated with equipment (3), comprising: at least one device (100) for measuring one or a plurality of physical quantities associated with the operation of the component; and a circuit for calculating a value representative of a remaining lifetime of a component, said monitoring circuit (5) being linked to the equipment.