A device for providing high DC voltage using a solid state normally open switch. The solid state switch is controlled to gradually rise the voltage of the DC output by applying ON/OFF modulation scheme. The modulation scheme opens the switch initially for a very short time duration around the zero crossing of the input AC voltage and gradually the duration of the ON state extends until the switch remains constantly open.

A power conversion device includes a converter, a first capacitor, and a second capacitor. The first capacitor is connected between a DC positive bus and a DC neutral point bus. The second capacitor is connected between the DC neutral point bus and a DC negative bus. The converter includes a diode rectifier connected between an AC power supply and each of the DC positive bus and the DC negative bus, and a first AC switch electrically connected between the AC power supply and the DC neutral point bus. The power conversion device further includes a first fuse electrically connected between the first AC switch and a connection point between the first and second capacitors.

A plurality of gate drive circuits each drive a gate of a corresponding one of a plurality of switching elements included in a converter and an inverter. Each gate drive circuit includes a gate driver and a power source circuit. The gate driver drives the gate potential of the switching element to a potential corresponding to H or L level, in accordance with the gate signal input from a controller to the gate electrode of the switching element. The power source circuit supplies power to the gate driver. When a first switch is ON and a second switch is OFF, the controller, upon detection of an abnormality of the power source circuit of the gate drive circuit, turns on the second switch and turns off the first switch. The gate drive circuit maintains the gate potential of the switching element during the period from when the abnormality of the power source circuit is detected to when the second switch is turned on.

A plurality of gate drive circuits each drive a gate of a corresponding one of a plurality of switching elements included in a converter and an inverter. Each gate drive circuit includes a gate driver and a power source circuit. The gate driver drives the gate potential of the switching element to a potential corresponding to H or L level, in accordance with the gate signal input from a controller to the gate electrode of the switching element. The power source circuit supplies power to the gate driver. When a first switch is ON and a second switch is OFF, the controller, upon detection of an abnormality of the power source circuit of the gate drive circuit, turns on the second switch and turns off the first switch. The gate drive circuit maintains the gate potential of the switching element during the period from when the abnormality of the power source circuit is detected to when the second switch is turned on.

A system includes a transformer having a primary winding and an auxiliary winding at a primary side of an AC-DC converter, the auxiliary winding reflecting an output voltage of a secondary winding of the transformer. A primary side controller includes an over-voltage protection (OVP) pin and an OVP circuit. A voltage divider includes a first resistor coupled between the auxiliary winding and the OVP pin and a second resistor coupled between the first resistor and a ground. The voltage divider provides, to OVP pin, a reduced voltage that is proportional to the output voltage. In absence of a pulse signal from a secondary side controller, the OVP circuit turns off a gate driver that drives a primary switch in response to the OVP voltage exceeding a reference OVP voltage. The primary switch is coupled between the primary winding of the transformer and the ground.

A system includes a transformer having a primary winding and an auxiliary winding at a primary side of an AC-DC converter, the auxiliary winding reflecting an output voltage of a secondary winding of the transformer. A primary side controller includes an over-voltage protection (OVP) pin and an OVP circuit. A voltage divider includes a first resistor coupled between the auxiliary winding and the OVP pin and a second resistor coupled between the first resistor and a ground. The voltage divider provides, to OVP pin, a reduced voltage that is proportional to the output voltage. In absence of a pulse signal from a secondary side controller, the OVP circuit turns off a gate driver that drives a primary switch in response to the OVP voltage exceeding a reference OVP voltage. The primary switch is coupled between the primary winding of the transformer and the ground.

The disclosure provides a single-stage isolated bidirectional converter and a control method thereof. The converter includes: a first full-bridge circuit unit, a half-bridge circuit unit, a second full-bridge circuit unit, a phase-shift inductor unit, a transformer and a filter capacitor. The transformer includes a first winding and a second winding, and the first winding is provided with a center tap. The center tap is connected to the first port, two ends thereof are connected to the midpoints of the two bridge arms of the first full-bridge circuit unit through the phase-shift inductor unit, and two ends of the second winding are connected to the midpoints of the two bridge arms of the second full-bridge circuit unit. Two ends of the first full-bridge circuit unit are connected to two ends of the half-bridge circuit unit; two ends of the half-bridge circuit unit are connected to two ends of the filter capacitor.

A switching power supply includes an input terminal and an output terminal, a voltage converter including a first switching circuit configured to serve as a trigger for inputting a voltage from the input terminal and a second switching circuit configured to serve as a trigger for outputting, after the input voltage is converted, the converted voltage from the output terminal O, a control circuit configured to output a control signal for selectively sequentially driving the first switching circuit and the second switching circuit, and a delay circuit configured to delay, based on the control signal for driving any one of the first switching circuit and the second switching circuit, a subsequent driving timing of the other switching circuit that is not driven to provide a dead time when both the first switching circuit and the second switching circuit are turned off.

A switching power supply includes an input terminal and an output terminal, a voltage converter including a first switching circuit configured to serve as a trigger for inputting a voltage from the input terminal and a second switching circuit configured to serve as a trigger for outputting, after the input voltage is converted, the converted voltage from the output terminal O, a control circuit configured to output a control signal for selectively sequentially driving the first switching circuit and the second switching circuit, and a delay circuit configured to delay, based on the control signal for driving any one of the first switching circuit and the second switching circuit, a subsequent driving timing of the other switching circuit that is not driven to provide a dead time when both the first switching circuit and the second switching circuit are turned off.

An isolated power converter and a hydrogen production system are provided. An electrical connection structure in the isolated power converter includes N secondary winding output bus bars, N rectifier circuit input bus bars, and a positive-negative bus bar, where N is greater than or equal to 1. A secondary winding may include M tapping points, and the secondary winding output bus bar and the rectifier circuit input bus bar that correspond to the secondary winding each include M copper bars that are insulated and stacked. The M tapping points of the secondary winding overlap the M copper bars of the secondary winding output bus bar at input ends of the M copper bars, respectively. The positive-negative bus bar includes two copper bars that are insulated and stacked.