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.

A method of powering a controller using an intermediate device with power from an environmental system may include receiving current from a power wire from the environmental system; passing the current from the power wire to a second command wire from the controller; monitoring the current flowing between the power wire and the second command wire while the current is below a threshold indicative of an amount of current used to power the controller from the environmental system; detecting when the current flowing between the power wire and the second command wire exceeds the threshold indicating that the controller is sending a command to the environmental system to perform the function; and sending a command to environmental system using a first command wire from the environmental system after detecting that the current exceeds the threshold.

A three-phase converter and a control method thereof are provided. The three-phase converter includes an AC terminal, three filter circuits, three bridge arm circuits, a capacitor module and a DC terminal connected in sequence and a controller. The midpoints of the filter circuits are connected to the midpoint of the capacitor module. The controller controls each bridge arm circuit to work in the first and second modes at different time in one line voltage cycle of the AC source. In the first mode, the bridge arm circuit works in a clamping state. In the second mode, the bridge arm circuit selectively works in a DCM mode or a TCM mode. A switching frequency is limited to be lower than a preset frequency. When the three-phase converter works with over 80% of a rated load, a time length of working in the second mode is ⅓˜⅔ of the line voltage cycle.

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.

A stacked half bridge converter may be configured to provide an AC output voltage from either a DC or an AC input voltage. The switching devices of the converter may be operated according to a plurality of switching sequences, each switching sequence including one or more switching patterns, each switching pattern including one or more switching states of the switching devices. The switching sequences, patterns, and states may be selected to improve operation of the converter, by regulating the voltage at a neutral point of the converter to reduce ripple, increase switching efficiency, protect the switching devices from overvoltages, and the like.

A power conversion device includes a single-phase full-wave rectifying unit, an electrolytic capacitor, a plurality of chopper circuits that are arranged between the single-phase full-wave rectifying unit and the electrolytic capacitor, each of the chopper circuits including a reactor, a first MOSFET connected in parallel with the single-phase full-wave rectifying unit, and a second MOSFET connected to a positive terminal of the electrolytic capacitor at one end and to the reactor and the first MOSFET at the other end, a first current detecting unit to bidirectionally detect a current flowing through the reactor, and a control unit to control an operation of the first MOSFET by using the detection result from the first current detecting unit.

A power conversion device capable of suppressing current backflow while also improving current responsiveness and power conversion efficiency is achieved. A snubber capacitor capable of absorbing switching surge is connected to a low-voltage side switching circuit that includes switching elements. Until a predetermined time elapses from when a request to start switching is received, a controller determines that the snubber capacitor has not reached full charge or near-full charge, and asynchronously controls the low-voltage side switching circuit and a high-voltage side switching circuit that includes switching elements. After the predetermined time elapses, the controller synchronously controls the low-voltage side switching circuit and the high-voltage side switching circuit, and also controls a duty ratio of the low-voltage side switching circuit and the high-voltage side switching circuit such that current does not flow back from the low-voltage side switching circuit to the high-voltage side switching circuit.

An integrated circuit for a power supply circuit that includes a transformer and a transistor controlling an inductor current flowing through a primary winding of the transformer. The integrated circuit includes a terminal configured to receive a voltage corresponding to the voltage of a secondary winding of the transformer when the transistor is in an off-state, a first detection circuit configured to detect that the inductor current is smaller than a first current value, and a determination circuit configured to determine whether an AC voltage applied to the primary winding of the transformer is a first or second AC voltage, both based on the received voltage in the off-state of the transistor. The integrated circuit is configured to drive the transistor in response to a detection result of the first detection circuit, a determination result of the determination circuit, and an output voltage of the power supply circuit generated from the AC voltage.

An integrated circuit for a power supply circuit that includes a transformer and a transistor controlling an inductor current flowing through a primary winding of the transformer. The integrated circuit includes a terminal configured to receive a voltage corresponding to the voltage of a secondary winding of the transformer when the transistor is in an off-state, a first detection circuit configured to detect that the inductor current is smaller than a first current value, and a determination circuit configured to determine whether an AC voltage applied to the primary winding of the transformer is a first or second AC voltage, both based on the received voltage in the off-state of the transistor. The integrated circuit is configured to drive the transistor in response to a detection result of the first detection circuit, a determination result of the determination circuit, and an output voltage of the power supply circuit generated from the AC voltage.