A power conversion device capable of shortening the time required for acceleration of a motor and a metal processing device including the power conversion device are provided. Then, a power conversion device 10 includes a converter 100 configured to convert an AC voltage from outside to a DC voltage Vo and a converter controller 107 configured to control the converter 100. The converter 100 includes a voltage doubler circuit 104 configured to boost the DC voltage Vo when activated, and outputs the DC voltage Vo having a voltage value different in accordance with the activation and stop of the voltage doubler circuit 104. The converter controller 107 activates the voltage doubler circuit 104 at a first time that is earlier by a predetermined period than a second time at which a speed command value ω* of the motor 130 rises from a predetermined value.

A power converter includes a converter circuit, an inverter circuit, a clamp circuit, a scrubber circuit, and an element including a resistive component. The converter circuit generates from an AC voltage source a DC voltage with AC components superimposed. The inverter circuit has an input connected with an output of the converter circuit. The inverter circuit is configured to convert the DC voltage into an AC voltage by switching, and output the AC voltage to an inductive load. The clamp circuit includes a first capacitor and a first diode connected in series. The clamp circuit is connected between a positive output and a negative output of the converter circuit. The snubber circuit includes a second capacitor and a second diode connected in series. The snubber circuit is connected between the positive output and the negative output of the converter circuit.

A power converter includes a converter circuit, an inverter circuit, a clamp circuit, a scrubber circuit, and an element including a resistive component. The converter circuit generates from an AC voltage source a DC voltage with AC components superimposed. The inverter circuit has an input connected with an output of the converter circuit. The inverter circuit is configured to convert the DC voltage into an AC voltage by switching, and output the AC voltage to an inductive load. The clamp circuit includes a first capacitor and a first diode connected in series. The clamp circuit is connected between a positive output and a negative output of the converter circuit. The snubber circuit includes a second capacitor and a second diode connected in series. The snubber circuit is connected between the positive output and the negative output of the converter circuit.

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.

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.

An electronic device utilizing a wireless charging system is provided. The electronic device includes a power source, a transmission coil, a full-bridge inverter electrically connected to the power source and the transmission coil, and a control circuit which communicates with an external device through the transmission coil, and controls the full-bridge inverter to transmit a power signal through the transmission coil. The control circuit may: receive, from the external device, a first control signal requesting that the power of the power signal be reduced to less than a specified power, in response to the first control signal, adjust the duty cycle of each of first to fourth gate signals for controlling the full-bridge inverter, and switch to a pulse width modulation (PWM) drive state in which an operation according to a first period and an operation according to a second period are alternately repeated.

An electronic device utilizing a wireless charging system is provided. The electronic device includes a power source, a transmission coil, a full-bridge inverter electrically connected to the power source and the transmission coil, and a control circuit which communicates with an external device through the transmission coil, and controls the full-bridge inverter to transmit a power signal through the transmission coil. The control circuit may: receive, from the external device, a first control signal requesting that the power of the power signal be reduced to less than a specified power, in response to the first control signal, adjust the duty cycle of each of first to fourth gate signals for controlling the full-bridge inverter, and switch to a pulse width modulation (PWM) drive state in which an operation according to a first period and an operation according to a second period are alternately repeated.

A resonant DC-DC converter may include an input for inputting a DC supply voltage, an output for providing a DC voltage to a load, an output rectifier to convert the converter voltage into a DC voltage, a resonant half-bridge inverter comprising two switches in series with a first serial resonant circuit to adjust the output current of the converter, and a second serial resonant circuit to block DC current in the converter and provide current continuity within the converter. The resonance of the first serial resonant circuit is measured after every start of the converter and each measurement defines the switching frequency of the half-bridge inverter. The switches of the half-bridge inverter wherein the driving of the half-bridge inverter includes a key gap during operation thereof. The resonance frequency of the second serial resonant circuit is at least slightly above the switching frequency of the half-bridge inverter.

A resonant DC-DC converter may include an input for inputting a DC supply voltage, an output for providing a DC voltage to a load, an output rectifier to convert the converter voltage into a DC voltage, a resonant half-bridge inverter comprising two switches in series with a first serial resonant circuit to adjust the output current of the converter, and a second serial resonant circuit to block DC current in the converter and provide current continuity within the converter. The resonance of the first serial resonant circuit is measured after every start of the converter and each measurement defines the switching frequency of the half-bridge inverter. The switches of the half-bridge inverter wherein the driving of the half-bridge inverter includes a key gap during operation thereof. The resonance frequency of the second serial resonant circuit is at least slightly above the switching frequency of the half-bridge inverter.

In accordance with at least one aspect of this disclosure, a method for pulse width modulation control includes resolving a reference vector for any number of active space vectors to determine a voltage offset for the reference vector, adding the voltage offset to each active vector to determine a modified modulated signal to be added to a carrier signal, and controlling, with a control module, a switching circuit based at least in part on the modified carrier signal.