Provided are a battery management system (BMS) and a battery system capable of accurately measuring a voltage without using a precise resistance element and reducing an error even when operating in a wide temperature range. Since a correction amount for the resistor included in the voltage measurement module is generated using a diagnostic power source configured independently of the battery system, and a voltage of the circuit included in the battery system is measured by applying the generated correction amount, the voltage may be precisely measured without using a high-precision resistance element. Since a changeover switch operates periodically to generate and apply an updated correction amount according to a changing environment, the voltage may be precisely measured even if it is applied to a system in which the environment continuously changes, such as a driving electric vehicle.

A battery unit includes a positive relay switch, a negative relay switch, a first resistor disposed in a third wiring portion extending between a positive external terminal and a negative external terminal, a second resistor serially connected to a portion on more negative side than the first resistor, a third resistor disposed in a second wiring portion and connected in parallel with the negative relay switch, a potential difference detection section capable of detecting a first potential difference which is a potential difference between the portion of the third wiring portion on more negative side than the first resistor and a negative terminal and a failure determination section for determining a failure of the positive relay switch and the negative relay switch respectively, based on the first potential difference.

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 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 industrial process field device includes an active component, a switch, a switch monitor, and a controller. The active component may be a sensor configured to sense a process parameter, or a control device configured to control a process of the industrial process. The switch is electrically coupled to first and second terminals. The switch monitor is configured to detect an open or closed state of the switch, and generate a first state output, a second state output, or a chattering state output. An anti-chatter circuit outputs a chatter stabilized state output based on the chattering state output. The controller is configured to set the switch in the open or closed state, and generate a notification based on any one of the first and second state outputs and the chatter stabilized state output that indicates at least one of the current state and a condition of the switch.

A circuit breaker monitoring system and method includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is configured to be mounted to a circuit breaker and to acquire a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker. The closing operation comprises: initiation of the closing operation; latch release; movement of a moveable contact towards a fixed contact; contact touch of the moveable contact with the fixed contact; stop of movement of the moveable contact. The sensor provides the temporal vibration signal to the processing unit, which determines a plurality of physical switch events and corresponding plurality of time points of the plurality of physical switch events over the closing operation of the circuit breaker.

A system and method for monitoring a circuit breaker monitoring system includes a vibration sensor, a processing unit, and an output unit. The vibration sensor is mounted to a circuit breaker acquires a temporal vibration signal over at least a temporal portion of a closing operation of the circuit breaker, wherein the closing operation comprises: initiation of the closing operation, latch release, movement of a moveable contact towards a fixed contact, contact touch of the moveable contact with the fixed contact, and stop of movement of the moveable contact. The vibration sensor provides the temporal vibration signal to the processing unit, which determines a plurality of features of the closing operation and an indication of operational functionality of the circuit breaker.

An electromagnetic relay diagnostic device includes: an operation detection unit including a first light-emitting unit emitting light when a current flows through a wiring line connected to a coil of an electromagnetic relay; an operation detection unit including a second light-emitting unit emitting light when a current stops flowing through the wiring line; an operation detection unit including a third light-emitting unit emitting light when detecting a change in conductive state of a wiring line connected to a contact of the electromagnetic relay; an operation detection unit including a fourth light-emitting unit emitting light when detecting that the change in conductive state of the wiring line has disappeared; an imaging unit capturing a moving image of the operation detection units; and a diagnostic unit calculating a contact-on operation time and a contact-off operation time using the moving image, and diagnosing whether an abnormality has occurred in the electromagnetic relay.

The present invention is provided with: a first contact in a first relay connected to a circuit to be grounded; a resistor which is connected between the first contact and the earth, and which suppresses the flow of electric current to the first contact when the first contact is closed; a second contact in a second relay connected in parallel to the resistor; and an interlocking control means which inhibits opening of the first contact in a closed state when the second contact is opened, and which inhibits closing of the first contact in an open state when the second contact is closed.

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.