A resonant converter includes a transformer, a resonant network, control circuit, primary and secondary circuits. One of the primary switches is turned on from a first switching moment until a second switching moment. The resonant network is coupled between the primary circuit and the primary winding. A current of the resonant network changes a direction at a first moment between the first and second switching moments. The secondary circuit is coupled to the secondary winding. One of the secondary switches is turned on during first and second preset time interval to increase the current in a direction by the secondary winding being clamped by a preset voltage, in which the output current is increased in an opposite direction or equal to zero.

The invention provides a series resonant LLC power converter unit to provide a plurality of power outputs. The power converter unit comprises a plurality of transformers arranged such that at least one primary winding of each transformer is connected in parallel and configured to provide a power output. An inductive element is positioned in parallel with at least one primary winding selected from said plurality of transformers, wherein the inductive element restricts variation in inductance for said plurality of transformers and power outputs in operation.

A resonant converter includes a transformer, a resonant network, control circuit, primary and secondary circuits. One of the primary switches is turned on from a first switching moment until a second switching moment. The resonant network is coupled between the primary circuit and the primary winding. A current of the resonant network changes a direction at a first moment between the first and second switching moments. The secondary circuit is coupled to the secondary winding. One of the secondary switches is turned on during first and second preset time interval to increase the current in a direction by the secondary winding being clamped by a preset voltage, in which the output current is increased in an opposite direction or equal to zero.

A resonant converter includes primary and secondary circuits, a transformer, a resonant network and a control circuit. The control circuit is coupled to the primary circuit and the secondary circuit, and configured to control primary switches of the primary circuit operating with a switching frequency. At least one of primary switches is configured to be turned on from a first switching moment until a second switching moment. The control circuit is configured to control secondary switches of the secondary circuit, such that at least one of secondary switches is turned on during a first time interval to increase a current of the resonant network in a first flowing direction and an output current in a second flowing direction or equal to zero.

A holdup energy arrangement can include a motor control module configured to connect to motor power electronics to operate an inverter to control a motor. The motor control module can operate at a lower voltage than the motor power electronics. The arrangement can include a power supply operatively connected to the motor control module and configured to provide power the motor control module and a converter operatively connected to the power supply and configured to be electrically connected to a DC link capacitor of the motor power electronics. The arrangement can also include a logic control module configured to control the converter to selectively allow energy to flow from the DC link capacitor, through the converter, and to the power supply to provide holdup energy to the power supply with energy from the DC link capacitor.

A front-end architecture system includes a system voltage input and a controller electrically connected to the system voltage input. The controller is configured and adapted to provide a voltage output to at least one controller output. The controller includes a single-ended primary-inductor converter (SEPIC) and a monitoring and switchover circuit. A method for controlling a voltage input to a low-voltage power supply (LVPS) includes receiving a system voltage input with a controller, wherein the controller includes a single-ended primary-inductor converter (SEPIC) and a monitoring and switchover circuit. The method includes providing a voltage output of the controller to at least one controller output. The method includes receiving the voltage output with a low-voltage power supply (LVPS) electrically connected to the at least one controller output.

A buck-boost converter includes a voltage input terminal, a voltage output terminal, a first switch, a second switch, an inductor, a third switch, and an auxiliary capacitor. The first switch includes a first terminal coupled to the voltage input terminal, and a second terminal. The second switch includes a first terminal coupled to the voltage output terminal, and a second terminal. The inductor is coupled between the second terminal of the first switch and the second terminal of the second switch. The third switch includes a first terminal coupled to the second terminal of the second switch, and a second terminal. The auxiliary capacitor is coupled to the second terminal of the third switch.

A power supply circuit having a first capacitor, a transformer including a primary coil having a voltage of the first capacitor applied thereto, a secondary coil and an auxiliary coil, a second capacitor having a voltage from the auxiliary coil applied thereto, a transistor controlling an inductor current flowing through the primary coil, a control circuit outputting a first control signal when supply of the input voltage is unstopped, or is stopped yet a voltage of the second capacitor reaches a first level, and outputting a second control signal thereafter when the voltage of the second capacitor further reaches a second level, a first drive circuit outputting a first drive signal for switching control of the transistor in response to the first control signal, and a second drive circuit outputting a second drive signal for controlling on-resistance of the transistor to discharge the first capacitor, in response to the second control signal.

A utility meter includes: a rectifier configured to rectify AC voltage from a power grid to generate a primary DC voltage supply; and a primary holdup circuitry, including: first capacitors coupled to a primary DC voltage rail and configured to store energy from the primary voltage supply; a switch coupled to the first capacitors; and a control circuit configured to control the primary holdup circuitry, wherein the control circuit is configured to: determine that a secondary DC voltage of a secondary voltage supply is approximately equal to a first specified threshold voltage; and generate a control signal to causes the switch to turn on and cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail.

The present disclosure provides a power supply system, including: a power source connected between a first node and a second node for applying an input voltage; a first circuit, connected between the first node and a second circuit; and configured to suppress oscillation caused by load variation of a load circuit that is connected between the first node and the second circuit, and to supply power to the load circuit when the power source is temporarily off; the second circuit, having a first port connected to the first circuit, a second port connected to the load circuit, and a third port connected to the second node; and configured to charge the first circuit and supply power to the load circuit; and a third circuit, connected between the first circuit and the load circuit; and configured to suppress a current flowing into the second circuit.