According to one embodiment, when an effective value of an input current flowing into a booster circuit rises to a value greater than or equal to a second set value, boosting of the booster circuit is started and, after the start, when the effective value lowers to a value lower than a first set value lower than the second set value, boosting of the booster circuit is stopped. Then, if the three-phase AC source is in an unbalanced state, the first set value is set to a value lower than usual.

This disclosure relates to an equivalent transistor and a three-level inverter, and pertains to the field of power electronics technologies. The equivalent transistor includes a first transistor, a second transistor, and a diode. A source electrode of the first transistor is electrically connected to a source electrode of the second transistor; a gate electrode of the first transistor is electrically connected to a gate electrode of the second transistor; and one end of the diode is electrically connected to a drain electrode of the first transistor, and the other end of the diode is electrically connected to a drain electrode of the second transistor. According to this disclosure, a reverse recovery time can be reduced, and a switching speed of the equivalent transistor can increase.

A power supply is disclosed. The power supply an output diode, a main switch coupled to the input filter and an output inductor coupled to the output diode and the main switch. The power supply also includes a bypass switch coupled to the main switch and configured to bypass the output inductor. A switch driver is included and the switch driver is configured to turn on the bypass switch and upon detecting the output diode in a blocking mode, turn on the main switch and turn off the bypass switch.

A switching mode power converter circuit is disclosed, comprising a first high-side switch and a first low-side switch coupled in series between an input voltage level and a reference voltage level, a second high-side switch and a second low-side switch coupled in series between the input voltage level and the reference voltage level, and a control circuit for controlling switching operation of the first and second high-side switches and the first and second low-side switches. The first high-side switch has a larger on-state resistance than the second high-side switch and the first low-side switch has a larger on-state resistance than the second low-side switch. The control circuit is configured to, during an on-state of the first and second low-side switches, control the second low-side switch to switch to the off-state and control the first high-side switch to switch to the on-state, so that the first high-side switch and the first low-side switch are both in the on-state. The application further relates to a method of operating such switching mode power converter circuit.

A switching element driving device for driving first and second switching elements of a half bridge circuit, the first and second switching elements being respectively formed in upper and lower arm units of the half bridge, and having respectively first and second freewheeling diodes connected thereto in antiparallel. The switching element driving device includes upper and lower arm driving circuits respectively configured to output first and second driving signals for driving the first and second switching elements, and a drive capability decision circuit configured to, responsive to turning on of the first switching element, set drive capability of the first driving signal to a first level and to change the drive capability of the first driving signal to a second level upon detecting a reverse recovery current of the second freewheeling diode of the second switching element, the first level being higher than the second level.

A control unit executes a first control and a second control. The first control is to control transmission power to target power by adjusting a duty of an output voltage of an inverter. The second control is to control a turn-on current by adjusting the drive frequency, the turn-on current indicating an output current of the inverter at a rising of the output voltage. When the transmission power exceeds a limit value larger than the target power during adjustment of the drive frequency by the second control, the control unit decreases the target power in the first control.

A power conversion apparatus includes a first semiconductor element pair that includes a MOSFET made of wide bandgap semiconductor material and a wide bandgap diode made of wide bandgap semiconductor material which is reverse parallel-connected to the MOSFET, a second semiconductor element pair that includes an IGBT made of silicon semiconductor material and a silicon diode made of silicon semiconductor material which is reverse parallel-connected to the IGBT, and a control circuit section for controlling switching operation of the MOSFET and the IGBT. The first and second semiconductor element pairs are connected in series to each other.

In a switching converter having an inductive load, a current may flow through the body diode of a transistor even though the gate of the transistor is being controlled to keep the transistor off. Then when the other transistor of the switch leg is turned on, a reverse recovery current flows in the reverse direction through the body diode. To reduce switching losses associated with such current flows, a gate driver integrated circuit detects when current flow through the body diode rises above a threshold current. The gate driver integrated circuit then controls the transistor to turn on. Then when the other transistor of the switch leg is made to turn on, the gate driver first turns the transistor off. When the gate-to-source voltage of the turning off transistor drops below a threshold voltage, then the gate driver integrated circuit allows and controls the other transistor to turn on.

A driving circuit for a switching element that drives a switching element of a current-driven type. The driving circuit includes a controller including a first terminal and a second terminal and that outputs a control signal to a gate terminal of the switching element. A first resistor, which regulates a current serving as the control signal, is connected to the first terminal, and a first capacitor is connected in parallel to the first resistor. A second resistor and a second capacitor are connected in parallel, and a current path extends from the first resistor and the first capacitor to the gate terminal and from a source terminal of the switching element to the second terminal of the controller. The second resistor and the second capacitor are in the current path.

A power supply apparatus includes a transformer including a primary coil, a secondary coil, and an auxiliary coil; a switching element connected in series to the primary coil; a first rectifying/smoothing circuit including a first diode and a first capacitor and configured to rectify and smooth a voltage induced in the auxiliary coil; a second rectifying/smoothing circuit including a second diode and a second capacitor, connected in parallel with the first rectifying/smoothing circuit, and configured to rectify and smooth the voltage induced in the auxiliary coil; and a controller configured to control the switching element. The controller is configured to detect the voltage induced in the auxiliary coil based on an output voltage of the first rectifying/smoothing circuit. A responsiveness of the second diode is better than a responsiveness of the first diode.