An electrical protection method for detecting an electrical fault in an electrical installation includes: measuring electrical variables by way of an auxiliary protection device, the electrical variables being associated with phase conductors; automatically analysing the measured electrical variables in order to identify a condition representative of a short circuit between phase conductors; detecting an electrical fault, such as a short circuit between the three electrical phases associated with the phase conductors without any neutral conductor involved, based on the measured electrical variables; triggering the opening of a switching device of the auxiliary protection device when an electrical fault is identified in order to disconnect one of the phase conductors, the switching device being connected to one of the phase conductors.

Systems and methods for tripping open circuit interrupters based on the detection of an arc flash using an accessory arc flash detection module are disclosed. The housing of the arc flash detection module is structured to be installed within the frame of a circuit interrupter. The detection module communicates with light sensors structured to detect light from arc flash events, and includes a controller configured to communicate with an electronic trip unit of the circuit interrupter. In one embodiment, the detection module is configured to alert the electronic trip unit that light indicative of arc flash conditions has been detected such that the electronic trip unit can determine whether or not to initiate a trip after determining the magnitude of current flowing through the circuit interrupter. In another embodiment, the detection module is configured to directly actuate a trip of the circuit interrupter based on the detection of light.

The present invention provides a pulse-controlled inverter comprising one or multiple semiconductor switches and freewheeling diodes arranged in parallel to each semiconductor switch. The semiconductor switches are triggered only when the current does not flow through a freewheeling diode which is arranged in parallel to the semiconductor switch. This allows the number of triggering processes for the semiconductor switch to be reduced. The reduced number of triggering processes for the semiconductor switches results in lower power losses and an increased service life of the entire system.

A system for detecting overloads of a motor comprises a motor configured to receive power via a lead line, a first sensing device configured to sense a temperature of a motor, and a second sensing device electrically coupled to the motor and configured to detect a target current of the motor and trigger a contact of the lead line associated with second sensing device when the target current equals or exceeds a trip value.

A motor controller circuit includes an electrical powertrain having a three phase input, a DC link and a three phase output, a controller including a processor and a memory, a first current sensor configured to sense a current at the three phase input, a second current sensor configured to sense a current at the three phase output, and a third sensor configured to sense a current at the DC link, and wherein the memory stores instructions configured to cause the processor to compare an operational model of the powertrain against a mathematical model of the powertrain and to detect a high impedance fault when a deviation between the operational model and the mathematical model exceeds a threshold.

A switching device has a current transformer for measuring in a potential-free manner a current to be switched by the switching device, a current sense amplifier, to which the unrectified measurement current of the current transfer is fed on the input side, and a controller, to which the output current of the current sense amplifier is fed on the input side and which is configured so as to digitalize the fed output current and to perform one or more performance-related measurements and to output the measurement results.

A power distribution system capable of automatic fault detection includes a lateral, a switch unit and a feeder terminal unit. The switch unit includes a circuit breaker coupled for transmitting electrical power to the lateral when making electrical connection, and a protection relay to provide a control signal that causes the circuit breaker to break electrical connection upon determining that the magnitude of a current provided by the circuit breaker is greater than a threshold current value. The feeder terminal unit detects whether or not the protection relay generates the control signal, so as to determine whether or not a fault has occurred in the lateral.

There is provided a neutral pole transformer module for a circuit breaker capable of minimizing an influence of external noise, detecting a neutral pole current at low manufacturing cost, and detecting a neutral pole current without modifying a configuration of an existing overcurrent relay or without installing an additional component in the existing overcurrent relay. The neutral pole transformer module for a circuit breaker comprises a ZCT configured to allow a transmission line of a neutral pole detection current output from the current transformer to pass therethrough and to provide a secondary output current signal obtained by reducing the neutral pole detection current in a predetermined ratio; a printed circuit board configured to convert the secondary output current signal into a voltage signal, and to differentiate the converted voltage signal and output the same; and an enclosure formed of an electrical insulator and enclosing the ZCT and the PCB.

A short circuit current detection device for a medium voltage or high voltage switchgear includes: a reed contact; and a holder for holding the reed contact, the holder being mountable with a defined orientation to a conductor of the switchgear. At a location where the holder is mounted, the conductor has a longitudinal axis. The conductor enables a current to flow through the conductor in a direction of the longitudinal axis. The holder positions the reed contact with respect to the longitudinal axis such that when a magnitude of the current flow through the conductor exceeds a threshold current value the reed contact closes.

A matrix converter includes one or more current sensors structured to sense current flowing through the matrix converter, a matrix of switches including a number of solid state transistors, and a control circuit structured to detect faults in power flowing through the matrix converter based on the sensed current, to control the matrix of switches to drive an external device, and to control the matrix of switches to switch to prevent power from flowing internal to the matrix converter, or external to the external device in response to detecting a fault in power flowing through the matrix converter.