A device and method for detecting a location of an arc event between a power bus and a coupler of an electric vehicle monitors an interface between the power bus and the coupler for the occurrence of an optical event. A determination is made if an arc event occurred based on the optical event, and upon determining the occurrence of an arc event at least one of a time the arc event occurred or a position of the electric vehicle at the time the arc event occurred is recorded.

A ground fault detection device includes: a capacitor operating as a flying capacitor; a first switching unit for switching between a state in which a positive electrode side of a battery and a first electrode plate of the capacitor are connected via a resistance, and a state in which the first electrode plate of the capacitor is connected to the ground via a measurement resistance; a second switching unit for switching between a state in which a negative electrode side of a high-voltage battery and a second electrode plate of a detection capacitor are connected with a resistance, and a state in which the second electrode plate of the detection capacitor is connected to the ground via the resistance; a control unit for controlling the first switching unit and the second switching unit; and an offset voltage divider circuit that divides and offsets the voltage generated in the measurement resistance.

A ground fault detection device includes: a capacitor operating as a flying capacitor; a first switching unit for switching between a state in which a positive electrode side of a battery and a first electrode plate of the capacitor are connected via a resistance, and a state in which the first electrode plate of the capacitor is connected to the ground via a measurement resistance; a second switching unit for switching between a state in which a negative electrode side of a high-voltage battery and a second electrode plate of a detection capacitor are connected with a resistance, and a state in which the second electrode plate of the detection capacitor is connected to the ground via the resistance; a control unit for controlling the first switching unit and the second switching unit; and an offset voltage divider circuit that divides and offsets the voltage generated in the measurement resistance.

The disclosure discloses a method and device for detecting insulation state in a conversion system, wherein the conversion system includes an excitation source, a converter having an input end coupled to the excitation source, a connection element coupled between an output end of the converter and a reference point, and a coupling impedance having a first end coupled to the excitation source and a second end coupled to the reference point, the method for detecting insulation state including steps of: S1, controlling at least one main power switch of the converter not to switch; S2, detecting a pulse current signal of the connection element; and S3, processing the pulse current signal and outputting a partial discharge information, the partial discharge information indicating an insulation state of an isolating transformer in the converter. The disclosure can overcome electromagnetic interference of high frequency steep waves on a partial discharge signal.

A system for acoustically detecting dielectric breakdown of, or partial discharge within, or on, an electrical device includes at least one electroacoustic (EA) transducer configured to detect an acoustic vibration of the electrical device, and a controller electrically connected to the at least one EA transducer. The controller is configured to receive a signal from the at least one EA transducer, and analyze the signal to determine whether the signal includes data associated with an acoustic vibration in a frequency range of dielectric breakdown and/or partial discharge of the electrical device. The applicability of such a system includes, but is not limited to, electronic parts or assembly screening, life characterization testing for materials and processes, diagnostic methods or aides, augmenting testing of components, assemblies or systems, and in service monitoring to support preventative or condition based maintenance to avert an in-service issues.

An electricity meter includes at least one input terminal, at least one voltage sensor, and at least one current sensor, and a processor unit arranged to acquire the voltage measurements and the current measurements, and to detect a first period during which the source current is less than a first predefined current threshold, and a second period during which the source current is greater than a second predefined current threshold, to acquire a first voltage measurement during the first period and a second voltage measurement during the second period, and to detect faulty clamping between at least one wire and the input terminal when at least one detection value representative of a difference between a first voltage measurement and a second voltage measurement is greater than or equal to a voltage threshold.

Embodiments of the present disclosure provide an insulation monitoring device applied to a power system and a power system. The power system includes at least one power electronic converter module. The insulation monitoring device includes an insulation component, a signal source, an impedance module, and a monitoring module. The insulation component at least partially wraps around the power electronic converter module. The signal source is electrically coupled to a circuit node in the power electronic converter module, the impedance module is connected between the signal source and the insulation component, and the monitoring module is configured to monitor an insulation resistance value of the insulation component, so that an insulation state of the power electronic converter module may be determined.

A relay diagnosis apparatus includes a first voltage detection circuit to generate first and second diagnosis voltages between positive and negative electrode terminals of a battery assembly and a chassis, respectively; and a controller to determine first and second insulation resistances between the positive and negative electrode terminals and the chassis, respectively, based on the first and second diagnosis voltages at first and second time points while respective relays are controlled into an off-state. The controller determines third and fourth insulation resistances between the positive and negative electrode terminals and the chassis, respectively, based on the first and second diagnosis voltages at third and fourth time points while the first and second relays are controlled into an on-state. The controller detects relay faults based on the insulation resistances.

An apparatus for testing insulated high voltage devices includes a first ground plane connected to a reference voltage potential having a first plurality of resiliently compressible conductive fibers extending therefrom and a second ground plane connected to the reference voltage potential having a second plurality of resiliently compressible conductive fibers extending therefrom. The first and second ground planes are arranged to receive an insulated high voltage device under test connected to a voltage potential greater or less than the reference voltage potential between them and configured such that at least a portion of the first and second pluralities of resiliently compressible conductive fibers are in compressive contact with the insulated high voltage device under test. A method of testing insulated high voltage devices is also presented herein.

A separator is placed on a surface of a substrate to prepare a test piece. A puncturing tool is stuck into the separator, from a side of the test piece opposite to where the substrate is placed, in a thickness direction of the separator. An electrical resistance between the puncturing tool and the substrate is measured. The separator is evaluated based on a magnitude of a load applied to the puncturing tool at the time when the electrical resistance has decreased to a predetermined value. Each of the substrate and the puncturing tool is electrically conductive.