An on-board charger is provided with a bulk capacitor adapted to couple to a vehicle traction battery and a relay for receiving electrical power from an external power supply and to pre-charge the bulk capacitor. A power factor correction (PFC) circuit is connected between the bulk capacitor and the relay. The PFC circuit includes a switch that is adjustable between an on-position and an off-position. The switch enables current flow from the relay to the bulk capacitor in the off-position. A snubber circuit is coupled to the switch to damp a transient voltage present at the switch during a transition from the on-position to the off-position. A processor is programmed to control the switch.

An AC-DC conversion circuit provides a three-phase power source. The AC-DC conversion circuit includes a first inductor, a second inductor, a third inductor, a switch bridge arm assembly, and a control unit. The switch bridge arm assembly includes three switch bridge arms, and each switch bridge arm includes an upper switch and a lower switch. A plurality of common-connected nodes between the upper switches and the lower switches are coupled to the three-phase power source through the first inductor, the second inductor, and the third inductor. The control unit turns on the upper switch and the lower switch to provide a current detection loop. The control unit acquires a magnitude of a first current flowing through the first inductor and a magnitude of a third current flowing through the third inductor, and determines whether a current detection mechanism of the first current and the third current is normal.

In a described example, a circuit includes a sensor, a controller and an amplifier. The sensor has a sensor input and a sensor output. The sensor input is adapted to be coupled to a chassis of a switch-mode power supply (SMPS). The controller has an input, a timing output and a level output. The input of the control circuit is coupled to the sensor output. The amplifier has a timing control input, a level control input and an amplifier output. The level control input is coupled to the level output of the controller. The timing control input is coupled to the timing output, and the amplifier output is coupled to the sensor input. The amplifier is configured to provide compensation pulses at the amplifier output having magnitude and timing to reduce common-mode noise on the chassis.

The present invention discloses a power factor correction circuit. The power factor correction circuit includes: a first bridge arm having a first switch and a second switch; a second bridge arm having a third switch and a fourth switch; a first inductor and a second inductor; a first capacitor and/or a second capacitor connected with a common point between the second inductor and the first inductor; and a third capacitor and/or a fourth capacitor, the third capacitor connected in parallel to the third switch based on an arrangement of the second capacitor and having a capacitance value same as that of the second capacitor, the fourth capacitor connected in parallel to the fourth switch based on an arrangement of the first capacitor and having a capacitance value same as that of the first capacitor.

The present invention discloses a charging power supply circuit and a control method thereof, the charging power supply circuit includes a PFC circuit, a driver module, and a high-voltage output circuit and a low-voltage output circuit both connected to said PFC circuit, wherein the PFC circuit is connected to AC mains, and the drive module is used to set the operation range of said PFC circuit to the range near the zero point of AC input voltage. Using the technical solution of the present invention can achieve keeping the topology on the demand for isolation and reduce the volume and cost of PFC circuits.

A power conversion apparatus includes: a reactor; a rectifier circuit that includes a first leg including switching elements connected in series and a second leg connected in parallel with the first leg, including switching elements connected in series; and a smoothing capacitor that smooths an output voltage of the rectifier circuit. The power conversion apparatus also includes an inverter that converts a direct-current voltage smoothed by the smoothing capacitor into a drive voltage for a motor and applies the drive voltage to the motor; a voltage detection unit that detects the direct-current voltage; and a control unit that controls operation of the rectifier circuit and the inverter. The control unit controls operations of the switching elements on the basis of an induced voltage induced in the motor and a detected value of the direct-current voltage.

A bridgeless PFC circuit includes: a control module that collects a current flowing through a current sampling element; and when the current flowing through the current sampling element is greater than a first threshold, the control module controls a switch element to be turned on. Based on the current flowing through the current sampling element, the switch element can be controlled to be turned on, thereby implementing zero-voltage turn-on of the switch element. Because the collected current does not change abruptly, a delay requirement on a sampling control circuit included in the control module is lowered, and a signal anti-interference capability of the control module is strong.

A voltage doubling phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminals are connectable to a single-phase AC power source and connect directly to two output terminals of the converter. The phase converter has a storage capacitor, three active half-bridge modules connected to the storage capacitor, and a controller. Two modules connect to the input terminals and charge the storage capacitor. The other module connects to a third output terminal. The controller switches the module connected to the third output terminal and one of the other modules to generate and shape a second and a resultant third phase.

A circuit technique substantially reduces the switching losses in an AC-DC power conversion system caused by turn-on characteristics of a main switch and the reverse-recovery characteristic of a rectifier. The losses are reduced by using an active soft-switching cell having a series inductor, a series capacitor, a main switch, a rectifier switch, and an auxiliary switch. The reverse-recovery related losses are reduced by the series inductor connected between the main and rectifier switches to control the rate of current change in the body diode of the rectifier switch during its turn-off. The main switch, the rectifier switch, and the auxiliary switch operate under zero-voltage switching (ZVS) conditions.

The control system includes a PFC circuit and a sampling control circuit, and the PFC circuit includes an inductor, a first power supply drive circuit, and a first bridge arm and a second bridge arm that are connected in parallel, and a first bridge arm midpoint is a serial connection point between a first upper bridge arm and a first lower bridge arm of the first bridge arm. The sampling control circuit is configured to control, based on voltages of two ends of an alternating current power supply, the first lower bridge arm to be turned on, so that the first power supply drive circuit starts charging. The sampling control circuit is further configured to: when charging duration of the first power supply drive circuit reaches first target duration, control the first lower bridge arm to be turned off, so that the first power supply drive circuit completes charging.