A system includes a dry contact with a first pair of switchable electrodes, a wet contact with a second pair of switchable electrodes, an arc suppressor, and a controller circuit operatively coupled to the arc suppressor and the first and second pairs of switchable electrodes. The controller circuit is configured to detect a failure of the wet contact and determine a stick duration associated with the first pair of switchable electrodes. The stick duration is based on a duration between an instance when a coil of the dry contact is deactivated and an instance of separation of the first pair of switchable electrodes during deactivation of the coil. The controller circuit generates, in-situ and in real-time, health assessment for the first pair of switchable electrodes based on a comparison of the determined stick duration with an average stick duration associated with a window of observation.

Systems, devices, and methods including: a relay, the relay comprising: at least one contact; a reflector attached to at least one contact; a sensor, the sensor comprising: an emitter configured to emit a pulse; a detector configured to receive a portion of the emitted pulse; where the reflector may be configured to reflect at least a portion of the emitted pulse to be received by the detector when the at least one contact may be in at least one of: an open position and a closed position

A method for automatically testing a relay is provided. The method includes applying power to a testing device for automatically testing the relay, determining a position of a selector switch based on a user selection for testing, selectively energizing the relay based on the position of the selector switch, detecting, by a hardware processor, an energize status signal from the selector switch, testing, by the hardware processor and based at least on the energize status signal, a control coil or a contact of the relay to generate a test result, and displaying, using display, the energize status signal and the test result.

The present disclosure provides functional test equipment for a device under test and method of testing the device under test. The functional test equipment includes a first power supply, a second power supply and a relay system. The first power supply is configured to generate a first supply voltage. The second power supply is configured to generate a second supply voltage different from the first supply voltage. The relay system is configured to electrically couple the first power supply or the second power supply to the device under test, wherein the first supply voltage is applied to the device under test for a first duration and the second supply voltage is applied to the device under test for a second duration less than the first duration.

A diagnostic method for solenoid valves includes detecting, at excitation of the solenoid, a variation rate of the supply voltage of the solenoid and comparing it with a predetermined value, generating an error signal if the variation rate is lower than the predetermined value, otherwise, detecting characteristics of the waveform of the solenoid current over a time interval between a moment of excitation of the solenoid and a moment wherein the movable core reaches end-stroke position, comparing the detected characteristics with threshold values, generating an alarm signal if the detected characteristics are lower than the threshold values, otherwise calculating the value of solenoid resistance and comparing it with a minimum resistance value and a maximum resistance value when the solenoid current is in steady state, and generating an alarm signal if the solenoid resistance value is lower than the minimum resistance value or greater than the maximum resistance value.

A method for estimating a property of an electrical switching device that includes an electromagnetic actuator that includes a coil. The method includes: measuring electric current flowing through the coil; measuring supply electrical voltage of a control circuit for the actuator; injecting an electric current pulse into the coil; identifying a first time corresponding to a time for which the current flowing through the coil reaches a predetermined threshold value when the current increases following the injection of the pulse; and identifying a second time corresponding to a time for which the current flowing through the coil again reaches the predetermined threshold value when the current decreases after a spike. The method further includes estimating a resistance of the coil on the basis of a ratio of a sum of the values of the voltage that are measured between the second time and the first time, to a sum of the values of the current that are measured between the second time and the first time.

A fault diagnosis method includes detecting a state of a relay device, sending a fault diagnosis trigger signal to the relay device based on the stateto enable the relay device to enter a fault diagnosis mode, where the fault diagnosis trigger signal includes one or more of a variable supply voltage value, a transmit/receive control signal, and a diagnosis control signal, detecting a state of the relay device in the fault diagnosis mode, determining a fault code based on the state, and determining a fault based on the fault code.

In a case where a load current flows in an energized state where a power supply is connected to a load, it is assumed that a measured voltage fluctuates due to a voltage drop caused by contact resistance of a relay contact, and thus the relay state cannot be accurately diagnosed. A relay control device that controls a relay connected between a secondary battery and a load device calculates, in a failure diagnosis during energization with the relay being closed, a contact resistance value of the relay based on a voltage applied to the relay and a current flowing through the secondary battery, and determines a first threshold set as a variable value in accordance with a temperature change amount of the relay and compares the calculated contact resistance value with the first threshold to diagnose a failure of the relay.

A power conversion device includes a power converter, a relay, and a welding detector. The welding detector includes a first resistor connected to a terminal of the relay on a first side, a capacitor and a second resistor, both of which are connected to a terminal of the relay on a second side, an application unit to apply an inspection signal to the relay via the capacitor and the second resistor, and a determiner connected between the capacitor and the second resistor, the determiner detecting a signal based on application of the inspection signal by the application unit to determine whether or not the relay is welded.

Disclosed are a gas density relay having a simulation check function and a simulation check method thereof, the gas density relay includes a gas density relay body, a simulation reference signal unit, a simulation check signal unit, a driving contact action mechanism, and an intelligent control unit. The intelligent control unit obtains, according to the check, by the simulation reference signal unit, of a simulation check signal generated by the simulation check signal unit, a current working state of a monitoring part, so as to quantitatively and accurately measure the precision of the gas density relay; by providing the driving contact action mechanism, the gas density relay body generates an alarm and/or a locking contact action to ensure that a contact execution mechanism of the gas density relay body and a contact itself are normal. The present application completes online simulation or virtual check of the gas density relay while being used for monitoring the gas density of a insulation or arc extinguishing electrical equipment, thereby improving working efficiency, reducing operation and maintenance costs, and guaranteeing safe operation of a power grid.