A low-voltage circuit in a bidirectional DC-DC converter converts output AC power from a high-voltage circuit to DC power to charge a smoothing reactor and discharge the smoothing reactor, and includes an active snubber circuit including switching elements and each having a backward diode and a snubber capacitor. The snubber capacitor of the active snubber circuit has its one end connected to a drain end of the switching elements, and has its other end connected to a node between a center tap of a high-frequency transformer and a smoothing reactor.

Provided are a control unit having a first control state in which a first switching element and a second switching element of one series circuit are turned on and a second control state to which the first control state shifts and in which a first switching element of another series circuit and the second switching element of the one series circuit are turned on, and executing control so as to apply predetermined voltage to the other side of a transformer during a predetermined time period during the first control state before shifting to the second control state.

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a hybrid DC link system operatively connected between a high side and a low side of the DC bus. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The hybrid DC link system includes a ripple current control branch in parallel with an energy buffering branch.

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a hybrid DC link system operatively connected between a high side and a low side of the DC bus. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The hybrid DC link system includes a ripple current control branch in parallel with an energy buffering branch.

A primary circuit and a secondary circuit each have a switching element, each operate as a power conversion circuit while the switching element is activated, and each operate as a rectifier circuit while the switching element is deactivated. While a generator provided at the primary side of a first power conversion device is stopped, a controller activates the switching element of the secondary circuit and deactivates the switching element of the primary circuit. Accordingly, the first power conversion device converts electric power input from the secondary side and supplies electric power for causing the generator to operate. While the generator is operated, the controller activates the switching element of the primary circuit and deactivates the switching element of the secondary circuit such that the first power conversion device converts electric power supplied from the generator and outputs the converted electric power to the secondary side.

In accordance with an embodiment, a method, includes operating a power converter that comprises an electronic switch connected in series with an inductor in one of a first operation mode and a second operation mode. Operating the power converter in each of the first operation mode and the second operation mode includes driving the electronic switch in a plurality of successive drive cycles based on drive parameter. Each of the plurality of drive cycles includes an on-time in which the electronic switch is switched on and an off-time in which the electronic switch is switched off.

Provided is a power converter device that can be properly configured. The power converter device is provided with: a plurality of power conversion units each comprising a pair of AC terminals, a pair of DC terminals, and a power conversion circuit for performing power conversion in one direction or in both directions between the AC terminals and the DC terminals and arranged along a first direction and a second direction different from the first direction; AC wiring for connecting the AC terminals of the plurality of power conversion units in series along the second direction with respect to each phase of three-phase AC; and DC wiring for connecting the DC terminals of the plurality of power conversion units in parallel along the first direction.

Provided is a power converter device that can be properly configured. The power converter device is provided with: a plurality of power conversion units each comprising a pair of AC terminals, a pair of DC terminals, and a power conversion circuit for performing power conversion in one direction or in both directions between the AC terminals and the DC terminals and arranged along a first direction and a second direction different from the first direction; AC wiring for connecting the AC terminals of the plurality of power conversion units in series along the second direction with respect to each phase of three-phase AC; and DC wiring for connecting the DC terminals of the plurality of power conversion units in parallel along the first direction.

We describe a photovoltaic (PV) panel system comprising a PV panel with multiple sub-strings of connected solar cells in combination with a power conditioning unit (microinverter). The power conditioning unit comprises a set of input power converters, one connected to each sub-string, and a common output power conversion stage, to provide power to an ac mains power supply output. Integration of the micro-inverter into the solar PV module in this way provides many advantages, including greater efficiency and reliability. Additionally, embodiments of the invention avoid the need for bypass diodes, a component with a high failure rate in PV panels, providing lower power loss and higher reliability.

An object of the invention is to improve precision of current detection in a switching system having plural switching circuits. A first PWM timing generation circuit generates an edge timing of a PWM signal by using a comparison value and a count value and drives a first switching circuit. A second PWM timing generation circuit generates an edge timing of a PWM signal of plural phases by using a comparison value and a count value and drives a second switching circuit. One of the switching circuits is an inverter circuit of a common shunt type in which a shunt resistor is provided commonly for plural phases. One of the PWM timing generation circuits shifts the generated edge timing so that an interval between an edge timing of one of the circuits and an AD conversion timing of the other becomes equal to or larger than a predetermined reference value.