The power conversion device includes a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor and a resonance assist circuit based on a closed-loop circuit including a first series circuit having a secondary winding of the coupled inductor, a first rectifying element, and an auxiliary switch element, a second series circuit having a tertiary winding of the coupled inductor and a second rectifying element, and an auxiliary capacitor to which the first series circuit and the second series circuit are connected. The secondary winding and the tertiary winding are separate bodies and the first series circuit and the second series circuit are connected in parallel to the auxiliary capacitor, or the tertiary winding is integrated with the secondary winding.

An AC input AC/DC Switching Mode Power Supply (SMPS) with Power Factor Correction (PFC) comprises a boost follower circuit (BFC), a hybrid bulk capacitance circuit (HBCC) and driver and control circuitry. The BFC senses the peak AC input voltage and adjusts a PFC output voltage Vdc dependent on the AC input voltage, to improve low line efficiency and reduce losses. The BFC may provide a stepless or step regulation mode to follow the AC input line voltage. The driver and control circuitry coordinates operation of the BFC and HBCC. The driver and control circuitry comprises comparator circuitry, which enables selective connection of bulk capacitors of different voltage ratings, responsive to a sense voltage from the BFC, to meet requirements for ripple voltage and hold-up times for different Vdc. This solution provides a reduction in capacitor height and volume, with associated improvement in the power density of an isolated AC/DC power supply.

An AC/DC Switching Mode Power Supply (SMPS) comprises a PFC stage, an isolated LLC DC/DC converter stage, and a control circuit that provides feedback/control signals to PFC and LLC controllers, to enable a plurality of operating modes, dependent on a sensed peak AC input voltage and required output voltage Vo. The PFC provides a first DC bus voltage Vdc (e.g. 200V) for low line AC input and a second DC bus voltage (e.g. 400V) for high line or universal AC input. A multi-mode LLC converter is operable in a half-bridge mode or a full-bridge mode. For low line AC input, output voltage Vo, and PFC output Vdc, the LLC operates in full-bridge mode; for high line input, output voltage Vo and PFC output 2×Vdc, the LLC operates in half-bridge mode; for universal AC input, output voltage 2×Vo, and PFC output 2×Vdc, the LLC operates in full-bridge mode.

A power factor correction “PFC” circuit for use in AC-DC conversion comprises first and second pairs of switches connected across input and output rails in a full bridge configuration, and a controller configured to control the operation of the switches such that one pair of switches is switched on and off at an AC input frequency and the other pair of switches is switched on and off at high frequency; and the switching frequency is alternated between the pairs of switches every n cycles of the AC input/output frequency. The circuit may include inductors on both input rails and may be used in a bidirectional power supply.

A charging device may include a Power Factor Correction (PFC) circuit including first to third inductors connected to each of first to third input terminals, and first to third switch legs connected to each of the first to third inductors; and a relay network including a plurality of relays. When the first input terminal, the second input terminal and the third input terminal are connected to each phase of three-phase powers, the relay network connects each phase of the three-phase powers to the corresponding one among the first switch leg, the second switch leg, and the third switch leg, and the PFC circuit is operated as a three-phase boost PFC, when a single-phase power is connected to one among the first input terminal, the second input terminal and the third input terminal, the relay network connects the single-phase power to the first and second switch leg, connects the third switch leg to the neutral point, and the PFC circuit is operated as an interleaved single-phase full-bridge PFC of single inductor type.

A charging circuit of an on-board charger, where a second end of a first power conversion circuit of the charging circuit is coupled to a first end of a second power conversion circuit, a high-voltage output end of the second power conversion circuit charges a power battery pack of an electric vehicle, and a first low-voltage output end of the second power conversion circuit supplies power to a low-voltage system of the electric vehicle. The first power conversion circuit is configured to, when the electric vehicle is in a charging mode, convert an alternating current input from a first end of the first power conversion circuit into a direct current and transmit the direct current to the first end of the second power conversion circuit.

A multi-phase interleaved PFC converter includes at least six switches coupled in a multi-phase interleaved circuit arrangement, and a control circuit. The control circuit is configured to turn on and turn off a first one of the switches according to a PWM signal to operate the first switch as an active switch having an off-time as a function of a duty cycle of the PWM signal, while turning on and turning off a second one of the switches as a synchronous switch. The control circuit is also configured to receive signal(s) indicative of currents in each phase of the interleaved circuit arrangement, set an on-time of the second switch equal to the off-time of the first switch when the signal(s) indicate continuous mode operation, and set the on-time of the second switch to a duration less than the off-time of the first switch when the signal(s) indicate discontinuous mode operation.

An embodiment charging device includes a power factor correction (PFC) circuit including first, second and third inductors and first, second and third switch legs connected to the first, second and third inductors, respectively, a relay network configured to control connection between the first, second and third inductors and first, second and third input terminals according to a phase of a power grid connected to the first, second and third input terminals, wherein the relay network includes a first relay connected between a neutral point and the third inductor, and a capacitor having a first end connected to the neutral point with respect to the first, second and third input terminals and a second end connected to ground, wherein the first end of the capacitor is positioned closer to the neutral point than the first relay.

A power factor correction converter includes a power stage circuit, a current sensing circuit and a zero current prediction circuit. The power stage circuit converts a rectified power to an output power. The power stage circuit operates in a boundary conduction mode to correct a power factor of the rectified power. The current sensing circuit senses an inductor current to generate a sensing signal. The zero current prediction circuit controls at least one switch by: generating a second period according to a first period, wherein the first period is between when the sensing signal passes a first threshold and when the sensing signal passes a second threshold; and switching a state of the at least one switch at an end time point of the second period, wherein the end time point corresponds to a zero current time point at which the inductor current reaches zero.

A vehicle power conversion system includes an input power supply including an AC power input, a battery, a power factor correction circuit connected to the input power supply, a power transmission unit including an inverter connected in parallel to the battery, a three-phase motor connected to the inverter, and at least one relay connected to the three-phase motor and configured to transfer power between the input power supply and the battery, and a buck converter including a first switching element and a second switching element, connected in parallel to the power factor correction circuit, wherein an end of the second switching element is connected in parallel to the power transmission unit, and wherein the buck converter is configured to step down an output voltage of the power factor correction circuit and transfer the stepped down output voltage.