The image forming apparatus of the present invention includes: a power source unit having a PFC (Power Factor Correction) circuit; a semiconductor integrated circuit including at least one module for performing image processing; and a first power source control unit configured to control whether to turn on or to turn off a power of the PFC circuit, and to control a power control signal input into the semiconductor integrated circuit so that the power of the PFC circuit is on while the power of the module in the semiconductor integrated circuit is on.

Systems, methods, and apparatus for a circuit with power factor correction (PFC) are disclosed. In one or more embodiments, the disclosed method comprises providing, by a single-stage power converter, a delay in phase between a peak current command and a rectified input voltage such that a phase of a transformer current intentionally lags behind a phase of the rectified input voltage to maintain a power factor (PF) level and a total harmonic distortion (THD) level for the single-stage power converter. In one or more analog embodiments, a resistor and a capacitor are implemented into a conventional single-stage power converter to provide the delay in phase between the peak current command and the rectified input voltage. In one or more digital embodiments, a controller within a conventional single-stage power converter exclusively provides the delay in phase between the peak current command and the rectified input voltage.

A three-phase alternating current system port is configured to receive or output a three-phase alternating current. M direct current system ports are configured to separately receive or output a direct current, where M is an integer, and M2. Three power conversion modules are configured to separately receive or output one phase alternating current in the three-phase alternating current. Each power conversion module includes at least one power unit. Each power unit is configured to implement conversion and galvanic isolation between a single-phase alternating current and a direct current. Each power unit includes one alternating current port and M direct current ports. The alternating current ports of the at least one power unit are connected in series and then connected to the three-phase alternating current system port. The M direct current ports of each power unit are separately connected to the M direct current system ports.

A battery charging apparatus includes a bi-directional charger including a first switching circuit connected to an AC terminal, a second switching circuit connected to a battery, and a transformer connected between the first switching circuit and the second switching circuit. The battery charging apparatus also includes a controller configured to switch a leg included in the first switching circuit based on a first carrier wave and a first duty command, configured to switch a leg included in the second switching circuit based on a second carrier wave and a second duty command, configured to adjust a phase of the second carrier wave compared to a phase of the first carrier wave by a phase shift angle according to an active power command, and configured to adjust a phase of the second duty command according to the reactive power command.

The present invention relates to an AC-DC power converter which includes a resonant DC-DC converter and a charge pump circuit. The charge pump circuit is configured to perform power factor correction of the AC-DC power converter by drawing current pulses at a switching frequency of the converter from an AC line voltage such that electrical charges of the current pulses vary substantially proportionally with instantaneous amplitude of the AC line voltage.

A power conversion system including power factor correction circuitry and power inversion circuitry. The power factor correction circuitry has a split-rail configuration and includes a bidirectional switch used to produce intermediate direct current power. The power inversion circuitry selectively operates switches to produce sinusoidal alternating current output power. The output power and the intermediate power are regulated together.

The present invention relates to an AC-DC power converter which comprises a resonant DC-DC converter and a charge pump circuit. The charge pump circuit is configured to perform power factor correction of the AC-DC power converter by drawing current pulses at a switching frequency of the converter from an AC line voltage such that electrical charges of the current pulses vary substantially proportionally with instantaneous amplitude of the AC line voltage.

A method of commutation in a matrix rectifier from an active vector to a zero vector includes two steps. A method of commutation in a matrix rectifier from a zero vector to an active vector includes three steps.

Two versions of an isolated single stage converter AC/DC Power Factor Corrected (PFC) converter topology have been invented. One is with a full bridge rectifier at its input and the other is a True Bridgeless version. The two versions of the topology feature new configurations and circuitry including a simplified damper circuit and a clamp capacitor flipping circuit and control methods that allow them to realize improved single stage isolated power factor converters which are suitable for high power operation, features Zero Voltage Switching to maximize conversion efficiency and to minimize Electro-Magnetic Interference generation, does not need an additional circuit to limit the inrush current, achieves reasonably low input current Total Harmonic Distortion (THD), and is easy to control. The second version provides a true bridgeless single stage isolated power factor converter with even higher efficiency and lower input current THD.

A current sensorless control system and a control method thereof for single stage isolated PFC converters based on DAB. By coordinating three control variables of the DAB converter, that is, the inside phase-shifting ratio of the primary side full-bridge, the inside phase-shifting ratio of the secondary side full-bridge, and the phase-shifting ratio between the primary and the secondary sides, the present invention does not need to design additional current controller for the control of the input current, and may make the input current sinusoidal by directly coordinating the output voltage controller, the input voltage and the current modulation step, thereby reducing system cost and the difficulty of controller design, enhancing the stability of the control system, and improving the dynamic performance.