A plurality of gate drive circuits each drive a gate of a corresponding one of a plurality of switching elements included in a converter and an inverter. Each gate drive circuit includes a gate driver and a power source circuit. The gate driver drives the gate potential of the switching element to a potential corresponding to H or L level, in accordance with the gate signal input from a controller to the gate electrode of the switching element. The power source circuit supplies power to the gate driver. When a first switch is ON and a second switch is OFF, the controller, upon detection of an abnormality of the power source circuit of the gate drive circuit, turns on the second switch and turns off the first switch. The gate drive circuit maintains the gate potential of the switching element during the period from when the abnormality of the power source circuit is detected to when the second switch is turned on.

A washing machine including a rotating tub and a motor applying a driving force to the rotating tub. The washing machine configured to generate a starting current to be applied to the motor when it is a start time of the motor, accelerate the speed of the motor stepwise while the starting current is applied to the motor, check a current of a torque component when it is determined as a deceleration time or a stop time, and apply a current of a magnetic flux component greater than the magnitude of the current of the checked torque component to the motor.

When an inverter and a converter are merely operated with their carrier waves synchronized with each other, current ripple of a smoothing capacitor connected therebetween might be increased. Accordingly, bipolar modulation PWM control is performed on the inverter, PWM control is performed on the converter, and the phase of the carrier wave for the inverter or the converter is shifted on the basis of AC output, whereby timings of currents flowing into the smoothing capacitor are made different from each other.

The present disclosure relates to a power converter device including a power factor correction circuit, a resonance converter circuit, and a zero voltage switching circuit. The power factor correction circuit is coupled to the primary side rectifier circuit, and includes a first switching circuit, a first control circuit and a first output circuit. The resonance converter circuit includes a second switching circuit and a second control circuit. The second switching circuit is coupled to the first output circuit, and the second control circuit is coupled to the secondary side rectifier circuit. The zero voltage switching circuit is coupled between the first control circuit and the second control circuit. The zero voltage switching circuit is configured to obtain a switching voltage of a switch element in the second switching circuit, and output an adjustment signal to the first control circuit according to the switching voltage.

Electric power conversion devices carry out feedback control, so that a difference between a duty ratio and a duty ratio target value may approach zero, while a duty ratio, which becomes the origin of a drive signal of a semiconductor switching element, is limited by a prescribed upper limit.

The control part issues a first operation result, which is limited by a first upper limit, with respect to an operation value which is on an operation process for controlling an output electric power, and further a second operation result which is limited by a second upper limit, which is set as a value higher than the first upper limit, with respect to an operation value. In addition, the control part is configured to carry out the proportional plus integral control, by a difference between the second operation result and a target value of the second operation result.

When an inverter and a converter are merely operated with their carrier waves synchronized with each other, current ripple of a smoothing capacitor connected therebetween might be increased. Accordingly, bipolar modulation PWM control is performed on the inverter, PWM control is performed on the converter, and the phase of the carrier wave for the inverter or the converter is shifted on the basis of AC output, whereby timings of currents flowing into the smoothing capacitor are made different from each other.

According to one embodiment, a power supply circuit includes a smoothing capacitor that is charged with a charge current from an output transistor and outputs a voltage as an output voltage; a control loop that controls a conduction state of the output transistor depending on a difference value between the output voltage and a reference voltage; and a gain adjustment circuit that adjusts a gain of the control loop depending on magnitude of the charge current after the charge starts.

A negative injection circuit is coupled to a power factor correction (PFC) controller of a power supply system and includes a downshifter configured to downshift a ground signal to generate a negative voltage signal, a variable impedance coupled between the downshifter and the PFC controller, and configured to inject a negative injection voltage into a voltage sampling input of the PFC controller, the variable impedance including a first current limiting resistor and a second current limiting resistor coupled in series with one another and between the downshifter and the voltage sampling input of the PFC controller, and a bypass switch configured to selectively short across the second current limiting resistor in response a range selection signal.

Electric power conversion devices carry out feedback control, so that a difference between a duty ratio and a duty ratio target value may approach zero, while a duty ratio, which becomes the origin of a drive signal of a semiconductor switching element, is limited by a prescribed upper limit. The control part issues a first operation result, which is limited by a first upper limit, with respect to an operation value which is on an operation process for controlling an output electric power, and further a second operation result which is limited by a second upper limit, which is set as a value higher than the first upper limit, with respect to an operation value. In addition, the control part is configured to carry out the proportional plus integral control, by a difference between the second operation result and a target value of the second operation result.

A converter for conversion between three-phase AC and a DC signal may include three phase terminals, a first and second DC terminal, conversion circuitry for conversion between three phase voltages of the three-phase AC signal and a first and second intermediate voltage at first and second intermediate nodes, and first and second buck circuits. The buck circuits each have three devices that are actively switchable for connecting switch-node terminals to any one of the three phase terminals. The first buck circuit includes a second switching device connected between the first intermediate node and the first switch-node terminal, and a first filter inductor connected between the first switch-node terminal and the first DC terminal. The second buck circuit has another second switching device connected between the second intermediate node and the second switch-node terminal, and a second filter inductor connected between the second switch-node terminal and the second DC terminal.