Provided are scan device and method of diagnosing scan chain fault. The scan device for diagnosing a fault includes a scan partition including a plurality of scan chains which include path control scan flipflops connected to scan flipflops in cascade. In the scan partition, connection paths of the scan flipflops are controllable. The connection paths of the path control scan flipflops are controlled to detect a position of a fault such that a fault range in the scan partition is reduced to diagnose the fault.

A computer-automated maintaining of circuit breakers in a power distribution infrastructure based upon operating conditions recorded during breaker events of particular identified circuit breakers is described herein. The breaker event data sets are accumulated initially by file servers in a variety of formats. A parser performs an automated parsing of the breaker event data sets to render breaker event records that are thereafter stored in a central data repository. Maintenance engines apply data analysis and decision logic to particular event records for particular identified circuit breakers obtained from the central data repository and issue requests for actions to be taken with respect to the particular identified circuit breakers based upon operating conditions experienced by the particular identified circuit breakers.

A system for monitoring a switchgear includes multiple infrared cameras with fields of view; a processing unit; and an output unit. The cameras acquire multiple image data of a plurality of phases of the switchgear, and the processing unit determines whether there is a phase imbalance in a specific phase comprising a determination from a plurality of image data that temperature information for a plurality of component parts and/or a plurality of connections for that specific phase has an overall enhanced temperature compared to the temperature information for the same plurality of component parts and/or the same plurality of connections for one or more other phases of the plurality of phases. The output unit is configured to output information that a fault or load imbalance has occurred in a phase.

A high-voltage relay system for a vehicle is provided. The system includes a relay, a first contact part positioned between a battery and a power converter, a voltage application unit, and a second contact part positioned between the voltage application unit and the ground. A first resistor is connected, at a first end thereof, in series to a second end of the second contact part and connected, at a second end thereof, to the ground. A controller operates the relay in response to an ON/OFF control signal to short-circuit or open the contacts at both ends of the first contact part or the contacts at both ends of the second and determines whether the relay fails based on the type of the ON/OFF control signal and the voltage value between both ends of the first resistor.

A state of a tripping solenoid in a circuit breaker is determined by a primary coil and a secondary coil wound around a hollow body of a solenoid. The secondary coil is positioned within magnetic coupling distance from the primary coil and is configured to produce a sensing voltage based on the primary coil voltage. A ferromagnetic plunger positioned in the hollow body, is configured to slide axially to a tripped position to trip the circuit breaker when a trip voltage is applied to the primary coil. A plunger position detecting circuit connected to the secondary coil, is configured to detect the position of the plunger in the hollow body of the solenoid based on the sensing voltage. A reduction or absence of the sensing voltage indicates a faulty or broken connection in the primary coil.

Embodiments of present disclosure relates to a method for monitoring vacuum interrupter’s condition of an electric device. The method comprises receiving a first voltage signal indicating a first voltage at a first contact of a switch inside the electric device. The first contact of the switch is coupled to a source line. The method further comprises receiving a second voltage signal indicating a second voltage at a second contact of the switch. The second contact of the switch is coupled to a reactive component. The method comprises receiving a current signal indicating a current at the second contact of the switch. The method comprises determining occurrence of a restrike in response to determining increasing amplitudes of the first voltage signal, the second voltage signal and the current signal in a time slot. The method further comprises determining the vacuum interrupter condition based on the determined occurrence of the restrike. By utilizing the embodiments herein, vacuum condition can be reliably monitored in a nonintrusive manner without significant cost.

Described herein is a method for determining a presence of anomalous conditions in a switching apparatus installed in an electric line of an electric power distribution grid. The method includes a sequence of steps for adjusting a lumped-parameter model describing, for each electric phase, the behavior of the switching apparatus during the opening maneuvers of the switching apparatus. Simulation values provided by the lumped-parameter model are used for calculating estimation values indicative of the amounts of arc energy released by the breaking components of the switching apparatus during the opening maneuvers of the switching apparatus.

The present disclosure relates to a device and a method for diagnosing a failure of an inverter initial charging circuit. The device for diagnosing a failure of an initial charging circuit according to the present invention is advantageous as follows: it is possible to detect whether a relay of the initial charging circuit is malfunctioning or not by using a photocoupler connected in parallel with an initial charging resistor of the initial charging circuit, on the basis that, if a current flows through the initial charging resistor in a relay-on state, the photocoupler is turned on; and it is possible to prevent component failure or burnout from occurring due to a high current flowing through the initial charging resistor in the case of a relay failure.

A power conversion device includes a first inverter and a control circuit that controls an on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings, where n is an integer of three or more. The control circuit generates a control signal to turn off all of n low-side switches and n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches and measures the n-phase voltages that change depending on patterns of on failures of the switches, and executes a first failure diagnosis to diagnose the on failures of the n low-side switches and the n high-side switches based on the measured n-phase voltages by referring to a table associating the patterns of the on failures of the switches with n-phase voltage levels.

Systems and methods for automatically verifying that power relays have been disconnected include relays arranged between two power sources. Test nodes are positioned between the relays on each line, and feed into a detection circuit. Voltage drop resistors, voltage drop diodes, an optocoupler, and additional resistors and capacitors are used to provide voltage isolation for the detection circuit. Relays are methodically opened and closed to check the individual functioning of each relay, and a digital signal generated from the detection circuit. The design of the system with detection circuit isolation provides a safer and lower cost system for verifying that relays are operating correctly, with less costly components than traditional systems.