A cascaded multilevel converter is disclosed. The converter comprises a plurality of modules coupled to form a branch, each of the modules comprising a switching circuit and a DC link for supplying DC voltage to the switching circuit. The converter further comprises a controller for controlling the switching circuit of each module to generate an AC voltage in the branch, wherein the controller is configured to: determine for each module a voltage across a capacitor of the DC link of the module, determine for each module a reference power value for charging the capacitor of the DC link of the module to a reference voltage value for the module, determine, from the reference power values of the modules, a common reference AC current value for AC current in the branch, determine, from the common reference AC current value, a common reference AC voltage value for AC voltage in the branch.

Embodiments of the present disclosure provide a buck and rectifier circuit, a wireless charging receiver chip, and a wireless charging receiver. The buck and rectifier circuit includes a rectifier module, a charge pump module, a filter unit, and a control unit. The rectifier module includes a first bridge arm unit and a second bridge arm unit, wherein the first bridge arm unit is connected to a non-inverting output terminal of an alternating current signal, and the second bridge arm unit is connected to an inverting output terminal of the alternating current signal. The charge pump module includes a first voltage converter unit and a second voltage converter unit, wherein the first voltage converter unit is connected in parallel to the second voltage converter unit. The control unit is configured to output a first pulse width modulation signal to control on or off of a switch transistor in the rectifier module, and output a second pulse width modulation signal to control on or off of a switch transistor in the charge pump module, such that an operating frequency of the charge pump module is a positive integer multiple of the frequency of the alternating current signal. According to the above method, power conversion efficiency during wireless charging may be improved.

Multi-port power adapters. At least one example is a method including: supplying a first bus voltage to a first device by way of a DC-DC converter coupled to a link voltage; supplying a second bus voltage to a second device by way of a second DC-DC converter coupled to the link voltage; converting an AC voltage to the link voltage by way of an AC-DC converter; selecting, by a shunt regulator, a setpoint for the link voltage based on the first bus voltage and the second bus voltage; and regulating the link voltage to the setpoint by the AC-DC converter.

A power supply device includes a transformer, a first rectifier, a voltage conversion module, and a control unit. The first rectifier is connected to a primary winding of the transformer, converts a received alternating-current voltage to a first direct-current voltage. The transformer is configured to convert the first direct-current voltage to a second direct-current voltage. The voltage conversion module is connected to the secondary winding of the transformer and configured to convert the second direct-current voltage to output a third direct-current voltage. The control unit, connected to the voltage conversion module, controls the voltage conversion module to adjust an output voltage or an output current of the power supply device.

Provided are a power supply conversion device and a charging control method. The device includes: a transformer; a first rectifier circuit connected to a primary winding of the transformer used for converting a received alternating current into a first direct current, a voltage value of the first direct current being a first direct-current voltage, and the transformer used for converting the first direct-current voltage into a second direct-current voltage; a voltage converter connected to a secondary winding of the transformer and used for converting the second direct-current voltage to output a constant direct-current voltage or a pulsating direct-current voltage; and a controller connected to the first rectifier circuit and the voltage converter and used for controlling the voltage converter to selectably output the constant direct-current voltage or the pulsating direct-current voltage according to a desired charging mode of a device to be charged connected to the power supply conversion device.

A power supply device includes a transformer, a first rectifier, a first voltage conversion module, a second voltage conversion module, and a control unit. The first rectifier, connected to a primary winding of the transformer, converts a received alternating-current voltage to a first direct-current voltage. The first voltage conversion module is connected to the first secondary winding of the transformer. The second voltage conversion module is connected to the second secondary winding of the transformer. The control unit, connected to the first voltage conversion module and second voltage conversion module, controls the first voltage conversion module or second voltage conversion module to adjust an output voltage or an output current of the power supply device.

Provided are a power supply conversion circuit and a power supply conversion method. The power supply conversion circuit includes a first direct-current conversion circuit connected to an electric load, a secondary transformer coil connected to the first direct-current conversion circuit, and a primary transformer coil coupled to the secondary transformer coil. The primary transformer coil is configured to generate, based on an initial voltage inputted to the primary transformer coil, an electromagnetic field and couple the electromagnetic field to the secondary transformer coil. The secondary transformer coil is configured to generate an induced current by virtue of the electromagnetic field, generate a secondary output voltage based on the induced current, and transmit the secondary output voltage to the first direct-current conversion circuit. The first direct-current conversion circuit is configured to adjust, based on a predetermined demand voltage of the electric load, the secondary output voltage to obtain a target voltage.

A power supply conversion circuit and a charging device are provided. The power supply conversion circuit includes: a first voltage conversion circuit that converts a voltage when the voltage exceeds a preset voltage range and outputs the converted voltage; a post-stage voltage conversion circuit that receives the converted voltage and converts the converted voltage into a target voltage for outputting; and a signal feedback circuit that feeds back a signal to the first voltage conversion circuit according to the target voltage, so that the first voltage conversion circuit is synchronized with the post-stage voltage conversion circuit.

A power supply circuit includes a rectifier circuit, configured to convert an alternating current inputted to the rectifier circuit into a direct current; a primary power supply conversion circuit having an input end connected with an output end of the rectifier circuit, configured to convert an input voltage of the primary power supply conversion circuit which is out of a preset voltage range into an output voltage of the primary power supply conversion circuit within the preset voltage range; and a secondary power supply conversion circuit having an input end connected with an output end of the primary power supply conversion circuit, configured to convert a direct current voltage outputted by the primary power supply conversion circuit into a target direct current voltage. A lower limit of the preset voltage range is greater than a minimum working voltage of the secondary power supply conversion circuit.

Disclosed in the embodiments of the present application is a power conversion circuit, comprising a direct current conversion circuit, a pulse width control circuit, and a transformer. The transformer comprises a primary transformer coil and a secondary transformer coil. The direct current conversion circuit is connected to the primary transformer coil, and is used for adjusting an initial voltage inputted to the direct current conversion circuit to a target voltage. The pulse width control circuit is connected to the primary transformer coil, and is used for generating a pulse square wave on the basis of the target voltage. The primary transformer coil is coupled with the secondary transformer coil. The primary transformer coil is used for generating an electromagnetic filed according to the pulse square wave, and coupling the electromagnetic field to the secondary transformer coil so that the secondary transformer coil generates an output voltage.