An LLC resonant converter includes a square wave generator having a first switch and a second switch, a resonant tank, a transformer, a synchronous rectifying (SR) unit having a first SR switch and a second SR switch, and a control unit. The control unit provides a first control signal controls the first switch, a second control signal controls the second switch, a first rectifying control signal controls the first SR switch, a second rectifying control signal controls the second SR switch. When a frequency control command is lower than a phase-shift frequency, the first control signal and the first rectifying control signal are frequency-variable and phase-shifted, and the second control signal and the second rectifying control signal are frequency-variable and phase-shifted.

A power supply control circuit that is able to reliably discharge to the internal power supply, even when the external power supply is cut off instantaneously. The power supply control circuit includes a voltage detection unit, an internal power supply generation unit, and a control unit. The voltage detection unit detects the voltage of the external power supply. The internal power supply generation unit generates the internal power supply, according to the external power supply. The control unit controls the discharging to the internal power supply according to at least the second control signal among the first control signal and the second control signal, when the detected voltage of the external power supply drops below the predetermined value.

A power supply for an information handling system includes a rectifier circuit that is coupled to a power factor correction circuit. The power factor correction circuit includes a bulk capacitor. An extended hold-up capacitor is coupled in parallel to the bulk capacitor, via an electronic switch. The electronic switch has a first terminal coupled to the bulk capacitor and a second terminal coupled to the extended hold-up capacitor. A control circuit is coupled to a third terminal of the electronic switch and controls the operation of the electronic switch. An extended hold-up circuit is coupled to the extended hold-up capacitor and an output terminal of the power factor correction circuit. A digital signal controller is coupled to the extended hold-up circuit. The digital signal controller controls the operation of the extended hold-up circuit, and a DC to DC converter is coupled to the extended hold-up circuit.

An electrical ride-through (ERT) unit is configured to apply a voltage to a drive circuit during disruptions of line voltage to the drive circuit. The ERT unit includes a capacitor on an ERT circuit that is prevented from applying the voltage to the drive circuit during normal operation of the drive circuit, and applies the voltage to the drive circuit during a voltage drop on the drive circuit.

The present invention relates to a method for simultaneous operation of a plurality of chopper circuits of a wind turbine power converter, the method comprising the steps of operating a controllable switching member of a first chopper circuit in accordance with a first switching pattern, and operating a controllable switching member of a second chopper circuit in accordance with a second switching pattern, wherein the first switching pattern is different from the second switching pattern during a first time period. In order to reduce switching losses the first switching pattern may involve that the controllable switching member of the first chopper circuit is clamped during the first time period. Additional chopper circuits may be provided in parallel to the first and second chopper circuits. The present invention further relates to a power dissipation chopper being operated in accordance with the before mentioned method.

A power converter comprises a buck converter portion, an energy storage portion, and a controller. A first inductor is connected between the cathode of a first diode at an input node, and a capacitor at an output node. The input node is connected to an input voltage via a first switch. A second inductor in the energy storage portion is magnetically coupled to the first inductor and is connected to a second diode. The cathode of the second diode is connected to a first terminal of the energy storage element, and a second terminal of the energy storage element is connected to a second terminal of the second inductor. The first terminal of the energy storage element is connected to the input node via a second switch. When the input voltage is not less than a threshold, the second switch is opened.

The disclosure concerns a switched-mode power supply comprising a module for charging and discharging an energy store including an electrical transformer. The device provides high configuration flexibility.

A power management circuit operable with low battery is provided. The power management circuit is configured to generate a time-variant average power tracking (APT) voltage based on a battery voltage supplied by a voltage source (e.g., battery). In examples disclosed herein, the power management circuit can be configured to remain operable when the battery voltage drops below a low battery threshold. Specifically, the power management circuit maintains the time-variant APT voltage at a constant level in response to the battery voltage dropping below the low battery threshold to thereby avoid drawing a rush current from the voltage source. As a result, a wireless device employing the power management circuit can remain operable with low battery to continue to support critical applications.

A holdup circuit includes a high-voltage generation circuit that outputs a high voltage and a holdup capacitor charging/discharging circuit that includes a holdup capacitor that is charged by the high voltage output by the high-voltage generation circuit. An inrush control circuit includes a constant-current source that includes a first transistor and a second transistor. During start-up, input current flows through the second transistor, and after start-up and during normal operation, the input current flows through the first transistor.

According to one aspect, embodiments herein provide an AC-DC converter comprising a rectifier, a capacitor, a DC bus coupled to the capacitor, a plurality of first switches coupled to the DC bus, a plurality of second switches coupled between the rectifier and the first switches, a transformer having a primary winding and a secondary winding, the primary winding coupled to the plurality of first switches, the plurality of second switches, and the rectifier, and the secondary winding coupled to an output, and a controller configured, in response to a determination that the input AC power is acceptable, to operate the plurality of second switches and the plurality of first switches such that output DC voltage is maintained at a desired output DC voltage level, and operate the plurality of first switches such that a DC bus voltage on the DC bus is maintained at a desired DC bus voltage level.