The electronic apparatus including a power factor correction (PFC) circuit and a control circuit configured to control an operation of the PFC circuit is provided. The PFC circuit includes a first inductor part connected to one end of an AC voltage part and a first switch connected to a first inductor in series; a second inductor part connected to another end of the AC voltage part and a second switch connected to a second inductor in series; an output part connected to the first inductor part and the second inductor part; and a switching part, and the control circuit identically applies a switch on/off signal to the first switch and the second switch, and selectively applies a switch on/off signal to the third switch or the fourth switch based on a magnitude of an input voltage input through the AC voltage part.

An apparatus and method for use in electrical conversion are described. The apparatus includes a bridge rectifier having an input side and an output side, and a switched capacitor line connected across the output side of the rectifier, wherein the switched capacitor line includes a capacitor, a charging leg and a switched discharge leg, and wherein the charging leg incorporates a transistor controlled so as to maintain a substantially constant charging current when the transistor is conductive.

In a switching power supply, a rectifying circuit outputs a first voltage. A switching circuit switches the first voltage into a switching voltage. An output circuit generates a second voltage based on the switching voltage. A feedback circuit generates the feedback signal based on the first and second voltages, and includes a carrier wave generation circuit that generates a carrier wave. The carrier wave has a non-linear shape at its rising edge and/or falling edge. A PWM circuit generates a PWM signal based on a comparison between the first voltage and a voltage of the carrier wave. Due to the non-linear shape, as the first voltage is higher, a pulse width of the PWM signal is changeable more greatly based on a change in the first voltage. A low-pass filter generates the feedback signal based on the PWM signal.

An electrical system including a three phase AC input supply and three or more H-bridge converter cells. Each H-bridge converter cell has: an active front end rectifier for receiving the three phase AC input supply and transforming it into a DC supply, thereby providing a rectifier current i.sub.i; a capacitor suitable to receive a capacitor current i.sub.C, the capacitor smoothing the DC supply; and an inverter suitable to receive an inverter current i.sub.o, wherein i.sub.o=i.sub.i−i.sub.C, said inverter transforming the received inverter current i.sub.o into a single phase AC supply. The system also including a control subsystem, which provides a signal to each active front end rectifier to vary its respective rectifier current i.sub.i such that the difference between the rectifier current i.sub.i, provided by the active front end rectifier, and the inverter current i.sub.o, received by the inverter, is substantially zero.

A power converting apparatus includes a rectifier converting alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit short-circuiting the alternating-current power supply via a reactor; and a controlling unit controlling the short-circuit unit in a half cycle of the alternating-current power supply. A correction amount using inductance of the reactor is set in the controlling unit, and the controlling unit changes, using at least a detection value of a power supply current and the correction amount, an ON time and an OFF time of a plurality of switching pulses, and controls, using changed switching pulses, an ON/OFF operation of the short-circuit unit.

According to one embodiment, there is provided a power converter including a totem-pole power factor correction circuit that can achieve reduction in recovery loss with a simple structure. A power converter according to an embodiment includes a totem-pole power factor correction circuit, a series connection of a first current detector and a second current detector, and a control circuit.

AC power supply device 1 includes input capacitors 11 and 12 connected at a neutral point X of a three-phase output, transistor bridges 20* (where * denotes U, V, and/or W) each consisting of PWM control badges 20*1 and 20*2 each including two switch elements, transformers T* connected to output terminals of the transistor bridges 20*, reactors Ls* connected to the transformers T*, smoothing capacitors 40* connected to the reactors Ls*. The transformers T* are autotransformers including a core 33* and windings 31* and 32* coupled with each other via the core 33*. One ends of the windings are connected to output terminals of the PWM control bridges 20*1 and 20*2, respectively, while the other terminals are connected to the reactors Ls*. The windings 31* and 32* are wound in such directions that magnetic fluxes generated in the core 33* are cancelled with each other.

A power conversion system includes a first rectifier and a second rectifier. The first rectifier is configured to operate at a first operating frequency. The first rectifier is configured to be connected with a three-phase power source. A first amount of power flows through the first rectifier from the three-phase power source. The second rectifier is configured to operate at a second operating frequency. The second rectifier is configured to be connected in parallel with the first rectifier, and a second amount of power flows through the second rectifier from the three-phase power source. The second operating frequency is higher than the first operating frequency, and the second amount of power is a fraction of the first amount of power.

A boost rectifier that operates with a single-phase input voltage includes (i) an input stage receiving the single-phase input voltage and including first and second input filter capacitors, (ii) a switching converter stage coupled to the input stage and including a rectification circuit and an inductor circuit, series-connected first and second switches providing a common terminal therebetween, and a phase output capacitor, (iii) an output stage that transfers energy stored in the phase output capacitor to an output load, (iv) a decoupling stage that provides high-impedance decoupling between the switching converter stage and the output stage, and (v) a control circuit configured to operate the first and second switches according to an output signal of a non-linear compensation circuit that combines a feedforward signal derived from both the input and output voltages of the boost rectifier with an output voltage feedback control signal.

A converter for converting a three-phase AC input into a DC output may include three phase input terminals and two output terminals, a phase selector for connecting the three-phase AC input to an upper intermediate node, a lower intermediate node, and a middle intermediate node. The phase selector includes semiconductor switches for selectively connecting the middle intermediate node to the three phase input terminals, and a controller. The electrical converter includes a boost circuit and a buck-boost circuit. The boost circuit includes an upper boost circuit, a lower boost circuit, and a common node. The buck-boost circuit has an output connected to the two output terminals in parallel with an output of the boost circuit, and includes at least two semiconductor switches that are actively switchable and connected in series across the output terminals. The middle intermediate node is connected to a common node of the two second semiconductor switches.