An electrical circuit protection device a processor-based controller configured to operate at least one solid state switching element in a manner responsive to a variety of different time-current conditions to protect a plurality of different electrical loads. A field deployable adaptor device is configured to communicate with the controller. The controller is configured with at least one pre-preprogrammed control algorithm or at least one selected setting for a control algorithm executable by the controller. At least one pre-preprogrammed control algorithm or at least one selected setting are predetermined by a manufacturer of the circuit protector device.

The present disclosure envisages an apparatus for providing protection against an insulation failure in an electrical appliance. A first isolating means is connected in phase line of the AC power source. A second isolating means is connected in the neutral line. At least one TRIAC, having two main terminals and one gate terminal, is connected in parallel to appliance. First main terminal is connected to the phase line between first isolating means and electrical appliance, and second main terminal is connected to the neutral line between second isolating means and electrical appliance. The gate terminal is connected to the body of electrical appliance. In the event of insulation failure, the TRIAC, upon being triggered, blows out the first and second isolating means and thereby electrically isolates the appliance from the AC power source.

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.

The present invention discloses a system for limiting a peak current of short-circuit current, which comprises a first a first high-frequency branch configured to provide a first high-frequency current to a first switch (1SKa) of a first phase branch of a three-phase AC when the first phase branch occurs a short-circuit, wherein the first high-frequency current is configured to cause a zero-crossing point of a short-circuit current to appear before a zero-crossing point of the three-phase AC; a second high-frequency branch configured to provide a second high-frequency current to a second switch (1SKc) of a second phase branch of the three-phase AC when the second phase branch occurs a short-circuit, wherein the second high-frequency current is configured to cause a zero-crossing point of a short-circuit current to appear before a zero-crossing point of the three-phase AC, a third phase branch of the three-phase AC connected in parallel with the first phase branch and the second phase branch and configured to always supply power. The present invention superimposes the high-frequency current on the original short-circuit current of the switch, thereby the total time from the arc generation to extinction at the zero-crossing point and then to the judgement by the control system is shorter than the time that the short-circuit current peak appears. Therefore, it can effectively lower the damage of the short-circuit current peak to the dynamic stability of the switch and lower the impact on system equipment.

A system for limiting a peak current of short-circuit current comprises a first high-frequency branch configured to provide a first high-frequency current to a first switch (1SKa) of a first phase branch of a three-phase AC when the first phase branch occurs a short-circuit; a second high-frequency branch configured to provide a second high-frequency current to a second switch (1SKc) of a second phase branch of the three-phase AC when the second phase branch occurs a short-circuit; and a third phase branch of the three-phase AC connected in parallel with the first phase branch and the second phase branch and configured to always supply power.

A system for detecting a fault in electric power conversion equipment having an input stage and an output stage includes an output voltage sensor positioned within the output stage and configured to generate an output voltage signal; an input current sensor positioned at the input stage and configured to generate an input current signal; and a processor configured to analyze the output voltage signal and the input current signal to determine an occurrence of the fault in the electric power conversion equipment.

A system for detecting a fault in electric power conversion equipment having an input stage and an output stage includes an output voltage sensor positioned within the output stage and configured to generate an output voltage signal; an input current sensor positioned at the input stage and configured to generate an input current signal; and a processor configured to analyze the output voltage signal and the input current signal to determine an occurrence of the fault in the electric power conversion equipment.

A circuit interrupter includes separable contacts; an operating mechanism; an electronic trip unit; and a current sensor assembly including: a harvester circuit having a primary conductor through which input current passes, a secondary winding and a harvester core structured to saturate at a first input current level, a Rogowski coil structured to measure voltage at an output of the Rogowski coil, the measured voltage indicative of output current of the Rogowski coil, where linearity of the output of Rogowski coil deviates more than a deviation tolerance based at least in part on saturation of the harvester core at the first input current level, and a compensation coil arranged at 180 degree opposite to the secondary winding of the harvester core, the compensation coil structured to delay saturation of the harvester core until the input current reaches a second input current level higher than the first input current level.

The invention relates to fluid drive systems used in fluid wells and brake systems for permanent magnet wellhead direct drives. The braking controller connects or disconnects a brake resistor from a back EMF. A variable frequency drive (VFD) drives the motor and communicates with the control circuitry of the brake controller. The control circuitry monitors the brake resistor and depending on the rotational speed and direction of the motor and operating state of the VFD, disconnects or connects the brake resistor. If the direction of the motor is in reverse and above a threshold speed, it connects the brake resistor. If the direction of the motor is in reverse and below the threshold speed, the control circuitry dissipates stored back EMF through the brake controller. The amount of stored back EMF corresponds to the time to empty a pump.

A system includes a converter for powering a synchronous electric machine to which it is connected by cables, an insulating device and a mechanism for short-circuiting phases of the machine. The system includes primary detectors for detecting an overcurrent in the converter and a securing device able to open the insulating device when receiving a primary detection signal emitted by the primary detector. The system also includes secondary detectors able to detect a short-circuit downstream from the insulating device and to emit a secondary detection signal toward the securing device, the latter actuating the closing of the mechanism for short-circuiting as long as they have already received a primary detection signal having led to the opening of the insulating device.