A solid state power controller, SSPC, having an input to receive supply current and an output for providing output current to a load in response to connection to the power supply, the solid state power controller further comprising at least one solid state switch and a controller to limit the power dissipated in the solid state power switch based on a measured voltage across the solid state switch and a predetermined power dissipation threshold for the SSPC to adjust the output current or voltage control signal of the solid state switch such that the actual power dissipation of the SSPC does not exceed the threshold.

A power supply includes a power converter, a protection circuit, and a control circuit. The protection circuit includes an input for receiving an input voltage, an output for providing an output voltage to the power converter, a first switching device coupled in a current path between the input and the output, and a second switching device coupled across the first switching device. The control circuit is configured to sense the input voltage and the output voltage, in response to the output voltage exceeding a first defined threshold, turn off the first switching device and turn on the second switching device to supply power to the power converter, and in response to the input voltage exceeding a second defined threshold, turn off the second switching device to disconnect the power source from the power converter. Other example power supplies and protection circuits are also disclosed.

A charge management system including a power distribution bus circuit for distributing energy from a power source to a load, and an intermediate energy storage circuit operably connected to a power distribution bus circuit for aiding in distribution of energy to the load. A charge management system controller may be configured to control the discharge of energy between the intermediate storage circuit and the power distribution bus circuit during one or more modes. Such a charge management system may enable the power distribution bus circuit to receive energy from the intermediate energy storage circuit before the power bus voltage drops in response to load demand, which may enable the power source to respond to perturbations in the power bus voltage and minimize inrush current from the power source. The system also may be used to soft-start high-power equipment, or absorb energy spikes associated with shut-down.

The proposed invention discloses a safe processing method for active voltage reduction of a ground fault phase of a non-effective ground system, for use in safe processing of a ground fault of a neutral point non-effective ground generator or distribution network. Non-effective ground system side windings of a transformer are equipped with a plurality of shunting taps. When a single-phase ground fault occurs, the shunting tap of the fault phase winding is selected to be short-circuited to ground directly or through an impedance to reduce the fault phase voltage to ensure that the fault point voltage is less than the continuous burning voltage of a ground arc to meet a long-term non-stop safe operation requirements. The proposed method can eliminate the instantaneous single-phase ground fault, suppress the permanent single-phase ground fault current, and limit the rising amplitude of non-fault phase voltage and the risk of non-fault phase insulation breakdown.

A system is provided for suppressing transient currents in electrical circuits to prevent damage to switching devices such as relays and/or solid-state switching devices. An associated automatic transfer switch (ATS) system (300) includes a primary power cord terminating in cord cap (302) for receiving power from a primary power source and a secondary power cord terminating in cord cap (304) for receiving power from a secondary power source. The system (300) further includes an output (306) for connecting to an output load such as a piece of electronic equipment. The output (306) may be a female outlet such that the system (300) can be directly connected to a male power port of a piece of equipment. The system (300) further includes a micro-ATS module (308) operative to sense a power outage or degradation of signal quality for the power signal of at least the primary power source and, in response, to switch the power supply from the primary source to the secondary power source. A surge suppression circuit (310) is interposed in the secondary power cord between the module (308) and the cord cap (304).

Disclosed is a method for at least partially removing the oscillations occurring at the end of a current discharge through the structural diodes for a switching structure supplying power to an inductive load in the form of an H-bridge and including two controlled high or low power switches forming part of a high circuit or a low circuit, respectively, between a respective output and a power source or a ground, the switching structure having one of its outputs below the ground potential and the other above the potential of the power source during the current discharge through the structural diodes. A detection or anticipation of the end of discharge and a forced preservation of a freewheel after the detection of the end of discharge are carried out, the forced preservation of the freewheel after the detection of the end of discharge taking place for a predetermined preservation time.

A high reliability AC load switching circuit is disclosed. In some embodiments, the AC load switching circuit includes a high-speed switch connected between the load and the voltage source, a cutoff switch connected between the load and the voltage source in parallel with the high-speed switch, and a level detector connected to the voltage source and to a control input of the high-speed switch. The high-speed switch may be a solid-state switch, for example, a TRIAC or a bidirectional switch, and the cutoff switch may be an electromechanical switch, for example, a relay. In some embodiments a snubber is connected in parallel with a solid-state switch. In some embodiments a microcontroller is connected to an electromechanical switch and the level detector. In some embodiments, both a first cutoff switch and a second cutoff switch are used.

A device for controlling a pre-charge current generated when electrically connecting a first terminal and a second terminal, according to one embodiment of the present invention, may comprise: a switch for controlling a magnitude of a current flowing between the first terminal and the second terminal; a first resistor for generating a base voltage of a first transistor in proportion to a magnitude of the pre-charge current flowing between the first terminal and the second terminal; the first transistor for limiting the magnitude of the pre-charge current when a voltage generated by the first resistor is equal to or greater than a predetermined threshold voltage; a photocoupler for receiving, in a state insulated from a first power source, an optical signal from the first power source and supplying power; a capacitor charged by the power supplied by the photocoupler; a second transistor for controlling the magnitude of the pre-charge current on the basis of a charging voltage of the capacitor; and a second resistor for controlling an operating time of the second transistor along with the capacitor.

A power circuit including a switching circuit and a soft start control circuit is provided. A first terminal of the switching circuit is configured to receive an input voltage. A control terminal of the switching circuit receives a control signal. A second terminal of the switching circuit is configured to provide an output voltage. The soft start control circuit generates the control signal according to the output voltage and a first reference voltage to control a turn-on state of the switching circuit. The soft start control circuit switches a slope of the control signal from a first slope to a second slope after the switching circuit is turned on and when a voltage value of the control signal is equal to a second reference voltage, wherein the first slope is less than the second slope to reduce an inrush current at the time when the switching circuit is turned on.

An arrangement (100) is disclosed, comprising an electrical pulse generating module (10) configured to generate at least one electrical pulse, and a transformer (20) electrically connected to the electrical pulse generating module (10). The electrical pulse generating module (10) comprises an electrical energy storage module (40) that can be charged or discharged, and a switch unit (50) controllably switchable between at least a conducting state and a non-conducting state. When the switch unit (50) is switched into the non-conducting state, a power supply (30) charges the electrical energy storage module (40) by way of a charging current. When the switch unit (50) is switched into the conducting state, the electrical energy storage module (40) is discharged to create an electrical pulse to be received by the transformer (20). The electrical pulse generating module (10) comprises a flyback protection unit (60) configured to protect the switch unit (50) against flyback upon the switch unit (50) being switched into the non-conducting state. The flyback protection unit (60) forms a current path (65) that bypasses the transformer (20), and is configured such that a relation between the voltage drop across the flyback protection unit (60) for the charging current and the voltage drop across the transformer (20) for the charging current is such so as to cause the charging current to be directed via the transformer (20) at least to some extent.