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.

The invention relates to an accumulator module (26) comprising a moisture-proof housing (28), in which a plurality of accumulator cells (31) is disposed, the contacts of which are electrically interconnected and which are routed to external contacts (30) of the accumulator module (26) disposed at the outer face of the housing (28). To be able to detect a short circuit between the external contacts (30) of the accumulator module (26) in the simplest and most efficient manner possible, it is proposed that a protection device (35) is disposed inside the housing (28), which protection device comprises a detection device (36), which is designed to detect a short circuit between the external contacts (30). Furthermore, the invention relates to a swimming and diving aid (10) comprising such an accumulator module (26).

In a multi-terminal DC power transmission system, a common control device is connected to a plurality of individual protective devices via a first communication network. Each of the individual protective devices is configured, when detecting change in current or voltage in a corresponding protection zone, to output a fault signal to the common control device via the first communication network and open the corresponding DC circuit breaker such that the corresponding protection zone is disconnected from the multi-terminal DC power grid and deenergized. The common control device estimates a fault occurrence zone where a fault occurs among a plurality of protection zones, based on a plurality of received fault signals. The common control device requests an individual protective device corresponding to a deenergized protection zone of the protection zones excluding the fault occurrence zone to reclose the DC circuit breaker such that the deenergized protection zone is restored.

In a multi-terminal DC power transmission system, a common control device is connected to a plurality of individual protective devices via a first communication network. Each of the individual protective devices is configured, when detecting change in current or voltage in a corresponding protection zone, to output a fault signal to the common control device via the first communication network and open the corresponding DC circuit breaker such that the corresponding protection zone is disconnected from the multi-terminal DC power grid and deenergized. The common control device estimates a fault occurrence zone where a fault occurs among a plurality of protection zones, based on a plurality of received fault signals. The common control device requests an individual protective device corresponding to a deenergized protection zone of the protection zones excluding the fault occurrence zone to reclose the DC circuit breaker such that the deenergized protection zone is restored.

A circuit includes comparator circuitry to sense a current through a load and compare the intensity of the current with a comparison threshold which can be set to a first, lower threshold value and a second, higher threshold value. Logic circuitry receives from the comparator circuitry a comparison signal having a first value or a second value based on whether the intensity is lower or higher than the comparison threshold. The logic circuitry is configured to assert a first overcurrent event signal or a second overcurrent event signal based on the comparison signal having the first value or the second value and the comparison threshold set to the first or second threshold value.

A circuit includes comparator circuitry to sense a current through a load and compare the intensity of the current with a comparison threshold which can be set to a first, lower threshold value and a second, higher threshold value. Logic circuitry receives from the comparator circuitry a comparison signal having a first value or a second value based on whether the intensity is lower or higher than the comparison threshold. The logic circuitry is configured to assert a first overcurrent event signal or a second overcurrent event signal based on the comparison signal having the first value or the second value and the comparison threshold set to the first or second threshold value.

Methods and apparatus are disclosed for battery current monitoring. An example apparatus includes a haptic device, an isolation switch to deliver power from a battery to the haptic device, an integrator to integrate a signal based on a current from the battery to the haptic device to generate an integrator output, and control logic to control the isolation switch based on a comparison of the integrator output to a threshold.

Methods and apparatus are disclosed for battery current monitoring. An example apparatus includes a haptic device, an isolation switch to deliver power from a battery to the haptic device, an integrator to integrate a signal based on a current from the battery to the haptic device to generate an integrator output, and control logic to control the isolation switch based on a comparison of the integrator output to a threshold.

A direct current circuit breaker, including: n in number circuit breaker modules connected in series, one energy-absorbing and voltage-limiting module connected in parallel to the n in number circuit breaker modules, and a trigger module. The n in number circuit breaker modules each includes a mechanical switch and a commutation branch circuit which are connected in parallel; each commutation branch circuit includes a charging commutation module and a commutation capacitor which are connected in series; the charging commutation module is configured to charge up the commutation capacitor and produce reverse current to cut off the mechanical switch; the one energy-absorbing and voltage-limiting module is configured to absorb energy stored in inductive elements of power systems after a fault current is cut off, so as to limit voltage and protect the mechanical switch, and n is a positive integer greater than or equal to 1.

Systems and methods provide an alternative high voltage cutoff technique for disconnecting a high voltage battery from an electrical network of a vehicle in the event of a fault condition. Embodiments include a vehicle system comprising an electrical bus and a battery module coupled to the electrical bus via a contactor and a disconnector. The vehicle system further includes a controller configured to switch the contactor to an open state, upon receiving a fault condition signal, and if the contactor failed to open, activating the disconnector to break electrical connection between the battery module and the electrical bus. In some embodiments, the fault condition signal is generated upon detecting a vehicular impact. In some embodiments, the disconnector is a pyrotechnic device powered by a vehicle battery included in the vehicle system.