Abstract: An electrical apparatus (10) comprises: first and second terminals (18,20) for connection to an electrical circuit; a chain-link converter (22) connected between the first and second terminals (18,20), the chain-link converter (22) including a plurality of chain-link modules (24), each chain-link module (24) including at least one switching element (26) and at least one energy storage device (28), the or each switching element (26) and the or each energy storage device (28) of each chain-link module (24) combining to selectively provide a voltage source; and a protection device (32) connected across an electrical block (34) that includes at least two of the plurality of chain-link modules (24), the protection device (32) including a plurality of series-connected semiconductor devices (36), wherein the protection device (32) selectively provides a current-conductive path to allow at least part of a current flowing in the electrical apparatus (10) to bypass the electrical block (34).

Abstract: Embodiments relate to a diode circuit which uses a Schottky diode. A parallel bypass branch has a switch and bypass diode in series. The operation of the switch is dependent on the voltage across the Schottky diode so that the bypass function is only effective when a desired voltage is reached. The diode circuit can be used as a replacement for a single diode, and provides bypass current protection preferably without requiring any external control input.

Abstract: Various embodiments may relate to a dimming drive circuit for an illumination apparatus and an illumination apparatus including the dimming drive circuit, wherein the dimming drive circuit includes a filter circuit unit and a bleeder circuit unit, a main control module connected to the filter circuit unit and the bleeder circuit unit, respectively, and an auxiliary control module configured to reduce the current of the bleeder circuit unit and/or to switch off the bleeder circuit unit according to a characteristic input current of the dimming drive circuit prior to switch-off of the bleeder circuit unit by the main control module in a first operation state of the dimming drive circuit, and to prevent the filter circuit unit from releasing electrical energy via the bleeder circuit unit in a second operation state of the dimming drive circuit.

Abstract: The present invention provides a power control device, a machine comprising the same and a power control method. The device is used for an integrated machine comprising a thin client and a display and comprises: a current detecting unit for detecting the current flowing through a port in the thin client connecting to the peripheral device; and a control signal generating unit for generating a control signal based on the intensity of the detected current to adjust the power consumption of the display and/or the thin client to maintain no increase in the power consumption of the integrated machine. The power control device, the machine comprising the same and the power control method of the present invention can be used to avoid low efficiency resulting from the power reservations for peripheral devices connected by a USB port.

Abstract: Provided is a voltage regulator including an overcurrent protection circuit in which an output voltage-output current characteristic exhibits an optimal fold-back characteristic even when an overcurrent state is detected. The overcurrent protection circuit includes a control circuit for generating a current in accordance with an output voltage, and controls a gate of an output transistor with use of a current obtained by subtracting the current from a sense current flowing in accordance with an output current.

Abstract: A voltage measurement is made between two points in a circuit. If the measured voltage exceeds a predetermined amount, a switch is operated to electrically connect the two points.

Abstract: A control device for a vehicle includes a relay adapted to switch whether a first battery electrically connected to a motor generator and a second battery electrically connected to an electric load of the vehicle are to be electrically connected or not by turning on/off the relay. The relay is turned off during a power operation of the motor generator to disconnect an electric connection between the first battery and the second battery. The relay is turned on during a regenerative operation of the motor generator to electrically connect the first battery and the second battery. In a case where an on-fixation failure of the relay is detected, the power operation of the motor generator is prohibited.

Abstract: Systems and methods are disclosed with multiple direct current (DC) voltage source inverters to supply power to an alternating current (AC) power system.

Abstract: An AC-DC converter converts an alternating-current voltage, supplied from an external power supply, to a direct-current voltage higher than a peak voltage of the alternating-current voltage, and outputs the direct-current voltage to a first power supply line. In a normal control mode, a DC-DC converter steps down a voltage of the power supply line through on/off control over a switching element to charge a main battery. On the other hand, in an upper arm ON control mode, the DC-DC converter charge the main battery while the switching element is kept in an on state. On the basis of a state of external charging, a control device applies the upper arm ON control mode when a condition that upper arm ON control is applicable is satisfied, and applies the normal control mode when the condition is not satisfied.

Abstract: A stacked voltage source inverter having separate DC sources is described herein. This inverter is applicable to low or medium voltage, low to medium power applications such as photovoltaic utility interface systems, battery storage application such as peak shaving with renewables, motor drive applications and for electric vehicle drive systems. The stacked inverter consists of at least one phase wherein each phase has a plurality of low voltage full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with fast switching and small low pass AC output filter. A system controller controls operating parameters for each inverter. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Abstract: An overload prevention system and method for an electric circuit having a plurality of components is disclosed, where each component has a set of pre-computed parameters. For each component, monitored parameters are observed; a limited value is computed using the pre-computed and monitored parameters; and it is determined if the limited value reached a limit. If the limited value reaches the limit; the system limits one of the monitored parameters. Pre-computed parameters can include time constant and rated current; monitored parameters can include current; and limited value can be component temperature. A time constant, rated current and rated temperature can be pre-computed such that the temperature stays at or below the rated temperature when the current is substantially equal to the rated current. Per unit values can also be used such that per unit temperature stays at or below unity when per unit current is substantially equal to unity.

Abstract: There are provided a protection circuit and a gate driving circuit for a semiconductor switching device. The protection circuit for a semiconductor switching device includes an overcurrent determining unit operated according to a gate signal to determine whether a load current flowing through the semiconductor switching device controlling the load current is an overcurrent, a load open determining unit determining whether a load is open, on the basis of a detection value from a current detection unit detecting the load current, and an error detection unit generating a fault signal when it is determined that the overcurrent flows and the load is open, while the gate signal is in a turned on level of the semiconductor switching device.

Abstract: The present invention provides to a default current testing method of the high voltage direct current converter valve composited by impulse voltage. The technical scheme of the invention composites the symmetrical positive and negative voltage and the impulse into asymmetric positive and negative high voltage, it makes the test valve voltage accurately achieve required peak value at the set time. The test circuit is simple relatively; the high voltage source of the default current test circuit is instead by surge generators. The test method is flexible, safe, and suitable for different DC project converter valves.

Abstract: The present invention provides a protection circuit. The protection circuit includes an output stage circuit and a feedback unit that generates a first current. Under a first condition that the first current is one of currents larger than and equal to a rated current and the first condition remains for a first period, the feedback unit controls the output stage circuit to restrict the first current. Under a second condition that the first current is one of currents larger than and equal to a restriction current and the second condition remains for a second period, the feedback unit controls the output stage circuit to terminate the first current.

Abstract: A fault current limiter is provided. According to an embodiment of the present disclosure, the fault current limiter includes a switch whose contact point is opened when a fault current occurs; a current limiting element configured to limit the fault current when the fault current occurs; and a diode being serial-connected to the current limiting element, wherein a breakdown voltage of the diode is higher than a voltage drop by an impedance of the switch when a normal current flows.

Abstract: A computing device including a power connector to interface with a power source, logic and power components on a current path from the power connector; the power connector providing electrical power to the logic and power components, and an inrush protection circuit on the current path between the power connector and the logic and power components, the inrush protection circuit including: a first power dissipation device and a second power dissipation device arranged in parallel on the current path, a feedback loop to detect an amount of current in the current path and to control the first power dissipation device to operate in a manner to dissipate detected inrush current, and a first time delay network in communication with the second power dissipation device and causing a delay for the second power dissipation device to transition to an on state, wherein during steady state.

Abstract: High voltage direct current systems are provided including one or more outlets and an electronic current limiter circuit associated with the one or more outlets. The electronic current limiter circuit is configured to limit current inrush when a connector is plugged into and/or unplugged from the one or more outlets when a direct current bus associated with the one or more outlets is energized so as not to damage the connector; and/or isolate direct current faults and/or excess current draw in a load connected to the one or more outlets so as to protect the system from shutdown.

Abstract: An improved current limiting circuit comprising a switch having a first terminal and a second terminal, the first and second terminal configured to connect a power supply to a load. A first resistor connected in series between the first terminal and a first constant current source. A second resistor connected in series between the second terminal and a second constant current source. A control circuit configured to measure a voltage drop across the first resistor and compare the voltage drop to a voltage drop across the switch.

Abstract: A system for supplying direct current and DC voltage is provided. The system comprise a first supply branch having a first DC voltage source and a power field-effect transistor of a current limiter which are connected in series, and a second supply branch having a second DC voltage source. The power transistor has a current/voltage characteristic with a first inverse polarization area without current limitation, and a second conduction area with current limitation based on a current threshold. The power field-effect transistor is connected to the first voltage source with an inverse polarization when the voltage source of the first branch is operating normally.

Abstract: A circuit protection device for monitoring a current flowing from an electrical distribution line through a trip mechanism to a load includes an input conductor configured to receive a current signal from a sensor. At least one resistor is arranged to receive the current signal from the input conductor, and provides a voltage signal proportional to the current signal. The circuit protection device includes a control circuit coupled in parallel with the resistor and a power supply that receives the current signal from the resistor and supplies power to the control circuit based on the current signal. The control circuit is configured to receive the voltage signal and determine an amplitude of the current flowing through the trip mechanism based on the voltage signal. The control circuit is also configured to determine whether a predetermined current threshold is exceeded and to generate a control signal to activate the trip mechanism.

Abstract: A system for controlling a solid state circuit breaker comprises a solid state power switch, and a controller for providing a gate voltage to the power switch. During turnoff of the solid state power switch, the controller reduces the gate voltage to an intermediate level for a specified time period and then reduces the gate voltage to a turnoff level.

Abstract: Provided is a converter control device which detects an on-failure of an auxiliary switch constituting an auxiliary circuit of a soft switching converter and can prevent element failures. A current sensor for detecting the current flowing in a coil is provided between a fuel cell and the. A controller sequentially detects current by use of the current sensor and makes a judgment as to whether or not the detected current has exceeded an overcurrent threshold value stored in a memory (not shown). When the controller judges that the current has exceeded the overcurrent threshold value, the controller judges that a second switching element has an on-failure, and performs a fail-safe operation by stopping the driving of a converter (for example, a U-phase converter) of an auxiliary circuit provided with this second switching element.

Abstract: A semiconductor switching element drive circuit includes a semiconductor that passes main current between first and second terminals when voltage is imposed to a gate terminal, and an over current protection circuit that decreases the main current when the main current is judged to become over current for a certain period when exceeding a predetermined current value when current value or voltage value proportional to an amplitude of the main current exceeds a threshold value. The circuit also includes a short circuit protection circuit that decreases gate voltage imposed to the gate terminal earlier than a fall of the main current produced by the over current protection circuit when the main current becomes larger than the over current in a period shorter than the certain period, and a threshold value change circuit that decreases a threshold value when the short circuit protection circuit decreases the main current.

Abstract: An input redundant circuit according to the present disclosure may include: a core power supply unit; a first input port connected to a first input voltage; a second input port connected to a second input voltage; a relay unit connected to the first input port and the second input port to supply one of the first input voltage and the second input voltage to the core power supply unit; and a surge current limiting unit coupled to the relay unit, configured to limit a surge current generated when the relay unit is switched between the first input voltage and the second input voltage.

Abstract: A photovoltaic energy conversion system, apparatus, and method for controlling DC sub-arrays of a photovoltaic array are disclosed. The method may include coupling each of N homerun branches from N sub-arrays to an inverter via N switches and monitoring current through each of the N homerun branches. A forward current through each of the N homerun branches is compared with a forward current threshold, and any backfeed current through any of the N homerun branches is compared with a backfeed current threshold. One or more of the N switches are opened in response to either the forward current exceeding the forward current threshold or the backfeed current exceeding a backfeed current threshold.

Abstract: Disclosed is an inrush current control circuit for controlling current into a high-current circuit block. The inrush current control circuit comprises a number of distributed switches and a digital control circuit coupled to at least one of the distributed switches. The digital control circuit is configured to switch a first group of the distributed switches in response to an enable/disable signal. The digital control circuit is further configured to switch a second group of the distributed switches after a first programmable delay. According to one embodiment, a method comprises switching a first group of distributed switches by a digital control circuit of an inrush current control circuit in response to an enable/disable signal, and switching a second group of the distributed switches by the digital control circuit after a first programmable delay, thereby resulting in regulation of a flow of an inrush current.

Abstract: The invention relates to an actuator circuit for actuating a circuit breaker controller, the circuit being characterized in that it comprises two branches in parallel between two terminals and in that the first branch includes only a first coil; the second branch includes a second coil having impedance that is lower than the first, in series with a switch controlled by a switch circuit.

Abstract: A short-circuit protection circuit of a light emitting diode (LED) is for protecting a plurality of LED strings from a short-circuit condition. The short-circuit protection circuit includes a short-circuit protection unit and a control unit. The short-circuit protection unit is coupled to the plurality of LED strings to execute a short-circuit protection. The control unit coupled to the short-circuit protection unit and the LED strings is configured to control the short-circuit protection unit according to at least one of a feedback voltage and a compensation voltage, so as to determine whether to trigger the short-circuit protection. The feedback voltage is generated from a cross voltage of one of the LED strings, and the compensation voltage is generated according to a comparison result between the feedback voltage and a reference voltage for controlling a power supply of the LED strings.

Abstract: An integrated circuit generating a driving signal to a load according to an input voltage and including an impedance switching unit, a first protection unit, a first detection unit and a control unit is disclosed. The impedance switching unit takes the input voltage as the driving signal according to a control signal. The first protection unit generates a first detection signal when a current passing through the impedance switching unit is higher than a predetermined current. The first detection unit detects a voltage of the impedance switching unit to generate a detection result. The control unit controls the control signal according to the first detection signal.

Abstract: An electromagnetic direct current (DC) power system includes a plurality of pulse forming networks (PFN) modules. Each pulse forming network (PFN) module includes a PFN circuit, a fault current limiting (FCL) circuit and a cooling system. The pulse PFN circuit is configured to generate a pulsed DC output power. The PFN circuit further includes at least one energy storage inductor with primary winding having a primary winding inductance that controls a primary impedance of the PFN circuit. The FCL circuit includes a secondary winding that electrically communicates with the primary winding. The FCL circuit is configured to receive fault energy existing in the PFN circuit during a fault event. The cooling system is configured to cool at least one of the primary winding and the secondary winding, and remove a portion of the fault energy.

Abstract: A system and method for providing isolated power to the gate driving circuits used in solid state switching devices is disclosed. Rather than using expensive isolated AC/DC power supplies, an isolation transformer is used to provide isolated AC voltage. In one embodiment, the primary winding of the isolation transformer is disposed across an independent AC source. In another embodiment, the primary winding of the isolation transformer is disposed across two phases of the AC power line. Isolated AC voltage is then generated across the secondary winding of the isolation transformer. This isolated AC voltage is then used by a non-isolated DC power supply, which generates the power for the gate driving circuit.

Abstract: A system and method for providing isolated power to the gate driving circuits used in solid state switching devices is disclosed. Rather than using expensive isolated AC/DC power supplies, an isolation transformer is used to provide isolated AC voltage. In one embodiment, the primary winding of the isolation transformer is disposed across an independent AC source. In another embodiment, the primary winding of the isolation transformer is disposed across two phases of the AC power line. Isolated AC voltage is then generated across the secondary winding of the isolation transformer. This isolated AC voltage is then used by a non-isolated DC power supply, which generates the power for the gate driving circuit.

Abstract: A surge protection device (SPD) includes a spark gap (SG) and in series to the spark gap (SG) a temperature-dependent resistance element (R) with positive temperature coefficient, wherein the spark gap (SG) has a certain holding current, wherein the resistance element (R) is sized such that when a switching temperature is reached, the current is limited such that the holding current of the spark gap is undercut and is switched off, and wherein the resistance element is sized such that in the case of a transient event, the switching temperature is not reached.

Abstract: A system/method for providing an optically triggered circuit breaker is provided. The system comprises a junction field-effect transistor (JFET) and gate drive coupled to the JFET's gate. The gate drive applies voltage bias (VG) to the gate and the gate drive is configured to bias VG so that the system allows current flow through the JFET in the Drain to Source or Source to Drain directions, or so that the system blocks voltages applied to the Drain and/or Source. The system also comprises a photodetector which detects light emitted by the JFET resulting from a fault condition. The photodetector transmits a signal to the gate drive to provide the selectively biased VG so that the system blocks voltages applied to the Drain and/or Source, in response to the light detection. A system/method for providing an optically triggered bidirectional circuit breaker comprising common source JFETs and two photodetectors is alternatively provided.

Abstract: A direct-current circuit breaker includes a switching unit inserted in the direct-current line; and a commutation circuit that includes a series circuit including a first current-limiting element and an interrupting unit that forms a current zero point by superimposing a resonance current on a direct current flowing in the direct-current line and interrupts the direct current at the current zero point, that is connected in parallel with the switching unit, and that becomes a flow path for the direct current after the switching unit is opened, wherein current interruption is performed by the interrupting unit after the switching unit is opened.

Abstract: A protection system for an IT electrical distribution system (EDS) has a floating reference conductor and two electrical conductors in the form of an active conductor and a neutral conductor. System includes two input terminals for electrically connecting to an MEN electrical power source that is upstream of system. Two output terminals are electrically connected to an electrical load in the form of an electrical motor for a compressor of an upright freezer display. Motor is downstream of the system. A protection device, in the form of an MCB, electrically connects terminals to allow a supply of electrical power from source to motor. MCB is responsive to a fault signal at a port for selectively electrically disconnecting at least one of terminals to prevent the supply of electrical power. A sentinel unit selectively generates the fault signal at port in response to the current in conductor being greater than a predetermined threshold.

Abstract: A novel system is offered for supplying power from an input node to a load coupled to an output node. The system may have multiple switches coupled between the input node and the output node. One or more limiting circuits may be configured for controlling the switches so as to limit outputs of the switches. For example, the limiting circuits may limit current through the respective switches. One or more timers may set a delay period for indicating a fault condition after the limiting is initiated.

Abstract: A bypass device of a refrigerator connected to an inrush current preventing device bypasses an input power when the input power is applied to the refrigerator, and a controller controls the input power input through the inrush current preventing device in response to a voltage measured by a voltage measuring device, recovers a function of the inrush current preventing device, and drives a compressor. Therefore, a standby time to re-drive the refrigerator is decreased and convenience is enhanced.

Abstract: Techniques are described for determining the amount of current flowing through an electrical conductor of an isolation device by measuring the voltage level across the electrical conductor. The isolation device also includes a sensor that provides a measure of the amount of current flowing through the electrical conductor. By using both the voltage level and the sensor to determine the amount of current flowing through the electrical conductor, the techniques provide for verifying the current measurements made by the isolation device. Also, the techniques provide for fast overcurrent protection.

Abstract: An inrush current protection circuit for charging a load to a target voltage, in which the inrush current protection circuit includes a first charging circuit and a second charging circuit. The first charging circuit charges a load to a first stage voltage, and there is a voltage difference existing between the target voltage and the first stage voltage. The second charging circuit charges the load form the first stage voltage to the target voltage, in which the first charge circuit charges slower than the second charging circuit.

Abstract: Apparatus disclosed herein implement a fast transient precision current limiter such as may be included in an electronic voltage regulator. The current limiter includes two current sense element/current clamp control loops. A fast response time control loop first engages and clamps a current spike. A precision control loop then engages to more accurately clamp the output current to a programmed set point. The precision clamping loop includes an inner loop to linearize the precision current sense element. The inner loop forces the drain-to-source voltage (VDS) of the precision sense element to track the VDS of the regulator pass element. A more precise clamping operation results. Overall speed is not sacrificed as the fast response time clamping loop operates in parallel to protect circuitry while the precision clamping loop engages.

Abstract: A fault current limiter system including a fault current limiter and a variable shunt current splitting device. The current splitting device includes first and second conductive windings, wherein the first conductive winding is connected in parallel with the fault current limiter and is configured to carry current in a first direction. The second conductive winding is electrically connected in series with the fault current limiter and is configured to carry current in a second direction opposite to the first direction so that the reactance of the first winding is negated by the reactance of the second winding during steady state operation of the fault current limiter system. Thus, a first portion of a steady state current is conveyed through the fault current limiter and a second portion of the current is conveyed through the current splitting device. The steady state current load on the fault current limiter is thereby reduced.

Abstract: A system that detects electrical disconnection of one connector from another connector includes a detection circuitry and a protection circuitry. The detection circuitry detects that a plug connector has been electrically disconnected from a corresponding receptacle connector. In response to the detection, the detection circuitry sends a signal to the protection circuitry. In response to the signal, the protection circuitry lowers or terminates power being supplied to a host device via one of the contacts of the plug connector. This helps to prevent shocks/shorts that may be caused by accidental disconnection of the plug connector.

Abstract: A vertical semiconductor power device includes a top surface and a bottom surface of a semiconductor substrate constituting a vertical current path for conducting a current there through. The semiconductor power device further includes an over current protection layer composed of a material having a resistance with a positive temperature coefficient (PTC) and the over current protection layer constituting as a part of the vertical current path connected to a source electrode and providing a feedback voltage a gate electrode of the vertical semiconductor power device for limiting a current passing there through for protecting the semiconductor power device at any voltage.

Abstract: An over-current protection circuit including, a current supply switch with a first terminal coupled to a supply current input and with a second terminal coupled to a supply current output. The current supply switch is switchable at least between an on-state, in which the current supply switch provides a conductive connection between the first terminal and the second terminal, and an off-state, in which the current supply switch interrupts the conductive connection between the first terminal and the second terminal. The over-current protection circuit receives a supply current via the supply current input and provides the supply current via the supply current output if the switch is in the on-state. The current supply switch includes High Electron Mobility Transistor.

Abstract: A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground.

Abstract: An exemplary aspect of the present invention is a current limiting circuit including: an output transistor that controls a current flowing to a load from a power supply; a current sense transistor through which a current dependent on a current flowing through the output transistor flows; a sense resistor connected in series with the current sense transistor; a potential difference detection unit that detects a potential difference generated between both ends of the sense resistor; a constant current generation unit that supplies a constant current to the potential difference detection unit; and a control unit that controls a conduction state of the output transistor based on a control voltage generated based on the potential difference and the constant current, in which the sense resistor is disposed so as to surround the potential difference detection unit.

Abstract: A new type of superconducting fault current limiter is disclosed, which can advantageously be used with high voltage transmission networks. The circuit is electrically connected to two terminals, which connect to the transmission network. The superconducting circuit is located within an enclosure or tank, which is electrically isolated from ground. Therefore, the voltage difference between the enclosure and the superconducting circuit, and between the enclosure and the terminals are significantly less than exist in current deployments. In some embodiments, the enclosure is electrically connected to one of the terminals, while in other embodiments, the enclosure is electrically isolated from the terminals. The circuit can be combined with other like circuits to address a wide range of current transmission network configurations.

Abstract: A current limiter (100, 200, 400, 500, 700) comprises a switch (110) and connection means (105, 125) to a load and to a DC-voltage source. A control component (115) measures the current from a load to a DC-voltage source to the switch and controls the switch (110) to an open position if the current is above a threshold. In the closed position, the switch (110) admits current from the load to the DC-voltage source. The current limiter also comprises a transmission line (120) with a first (121) and a second (122) end. The first end (121) is connected to the input port of the switch (110), and the second end (122) is left open or connected to make the transmission line (120) connected in series with the switch (110).

Abstract: An intrinsically safe energy limiting circuit for connection between an upstream DC power source and a downstream electrical load powered from the upstream DC power source, wherein the circuit comprises from upstream to downstream an input to be connected to the DC power source, an electronic current limiter configured to limit a current through the circuit to a maximum value if the current reaches this value, a fuse designed to open at a current value greater than the maximum value, a DC-to-DC converter configured to convert a DC input voltage to a lower nominal DC output voltage, a zener barrier having a zener voltage higher than the DC output voltage, and an output for connection to the electrical load.