A contactor apparatus and method for operating the contactor apparatus can include a contactor assembly with a contactor coil operably coupled to a contactor switch. One or more sensors can be provided in the contactor assembly adapted to measure one or more aspects of the contactor assembly. Based upon the measured aspects, a controller can initiate operation of the contactor switch to effectively toggle the contactor switch at a zero-crossing point along an alternating current waveform.

A contactor apparatus and method for operating the contactor apparatus can include a contactor assembly with a contactor coil operably coupled to a contactor switch. One or more sensors can be provided in the contactor assembly adapted to measure one or more aspects of the contactor assembly. Based upon the measured aspects, a controller can initiate operation of the contactor switch to effectively toggle the contactor switch at a zero-crossing point along an alternating current waveform.

A circuit breaker comprises a solid-state bidirectional switch, a switch control circuit, current and voltage sensors, and a processor. The solid-state bidirectional switch is connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-on state and a switched-off state. The switch control circuit control operation of the bidirectional switch. The current sensor is configured to sense a magnitude of current flowing in an electrical path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage on the electrical path and generate a voltage sense signal. The processor is configured to process the current and voltage sense signals to determine operational status information of the circuit breaker, a fault event, and power usage information of a load connected to the load output terminal.

An electric device comprises a first and second voltage sensor, a current sensor, an actuator and a controller. The first voltage sensor senses a first voltage at a first contact of a switch inside the electric device and generates a first voltage signal indicating the first voltage, the first contact of the switch coupled to a source line. The second voltage sensor senses a second voltage at a second contact of the switch and generates a second voltage signal indicating the second voltage, the second contact is coupled to a reactive component. The current sensor senses a current at the second contact of the switch and generates an output signal indicating the current. The controller is coupled to the voltage sensors, the current sensor and the actuator and causes, based on at least one of the voltage and current signals, the actuator to actuate one of the contacts to execute switching at a predetermined point of the first voltage.

A circuit interrupter includes a first set of contacts connected in series with a second set of contacts, with both sets of contacts configured to open and close simultaneously. First and second arc extinguishers are associated with the first and second sets of contacts, respectively. A moveable permanent magnet moves as the sets of contacts simultaneously open and close, the moveable magnet generating a moveable magnetic field, a first stationary permanent magnet associated with the first arc extinguisher, the first stationary magnet generating a first stationary magnetic field, where the first stationary magnetic field and the moveable magnetic field are additive, and a second stationary permanent magnet associated with the second arc extinguisher, the second stationary magnet generating a second stationary magnetic field, where the second stationary magnetic field and the moveable magnetic field are also additive.

Various embodiments of the teachings herein include a switching device for a DC voltage grid. The device may include: a first controllable semiconductor switch with a control contact and two load contacts; and a controller for the first switch using a control signal at the control contact. The controller is configured to: actuate the first switch using a control pulse that causes the electrical conductivity of the semiconductor switch to reduce for less than 1 ms; apply a current to a test circuit including the first switch; ascertain a first value representing the voltage or the change in voltage across the first switch as a result of the control pulse and the applied current; analyzing the first value; and generating a signal that represents the functionality of the first semiconductor switch.

Disclosed is a DC circuit breaker capable of interrupting fault currents flowing in both forward and backward directions. The DC circuit breaker includes: a mechanical switch installed on a DC transmission line and being opened to interrupt a current in the DC transmission line when a fault occurs at one side or remaining side thereof on the DC transmission line; a first bidirectional switching device connected in parallel with the mechanical switch and switching currents flowing in both forward and backward directions; an LC circuit connected in parallel with the mechanical switch and including a capacitor and a reactor connected in series to induce LC resonance; a first unidirectional switching device connected in parallel with the LC circuit and switching a current to induce LC resonance; and a second bidirectional switching device connected in series with the LC circuit and switching currents flowing in both forward and backward directions.

A sliding power contact and method includes a mobile load device connector and a socket. The mobile load device connector includes a non-current power pin having a first length, a current power pin having a second length less than the first length, a neutral pin, and a ground pin. The socket includes a non-current power contact configured to electrically couple with the non-current power pin, a current power contact configured to electrically couple with the current power pin, a neutral contact configured to electrically couple with the neutral pin, and a ground pin configured to electrically couple with the ground pin. An arc suppressor is directly coupled to at least one of the non-current power pin and the non-current power contact, wherein the arc suppressor, the non-current power pin and the non-current power contact form a current path between the current power pin and the current power contact.

The invention relates to a method and a device for cutting off electric current. The device comprises at least one fixed contact and at least one moving contact that can move between a closed position and an open position, and at least one permanent magnet mounted together with the moving contact, such that the permanent magnet and the moving contact are able to move at the same time. The magnetic field of the magnet interferes with the area where the arc occurs and moves with the moving contact along its path, so with a small number of magnets, arc quenching capacity increases. The method of the invention comprises moving a permanent magnet through the area where an electrical arc occurs between a moving contact and a fixed contact, such that the generated magnetic field runs through at least part of the area where the arc occurs.

A circuit breaker includes an electromechanical switch, a current sensor, a voltage sensor, and a processor. The electromechanical switch is serially connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-closed state or a switched-open state. The current sensor is configured to sense a magnitude of current flowing in a path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage at a point on the path between the line input and load output terminals and generate a voltage sense signal. The processor is configured to receive and process the current sense signal and the voltage sense signal to determine operational status information of the circuit breaker and determine power usage information of a load connected to the load output terminal.