A voltage conversion unit includes a positive voltage conversion apparatus and a negative voltage conversion apparatus. The inverter unit includes a positive inverter and a negative inverter. A negative output end of the positive voltage conversion apparatus and a positive output end of the negative voltage conversion apparatus are connected to a first end of a neutral wire, and a negative input end of the positive inverter and a positive input end of the negative inverter are connected to a second end of the neutral wire. When the neutral wire current does not meet the preset current range, the controller control the positive voltage conversion apparatus and the negative voltage conversion apparatus to change output voltages when output power remains unchanged, so that the neutral wire current meets the preset current range.

A voltage conversion unit includes a positive voltage conversion apparatus and a negative voltage conversion apparatus. The inverter unit includes a positive inverter and a negative inverter. A negative output end of the positive voltage conversion apparatus and a positive output end of the negative voltage conversion apparatus are connected to a first end of a neutral wire, and a negative input end of the positive inverter and a positive input end of the negative inverter are connected to a second end of the neutral wire. When the neutral wire current does not meet the preset current range, the controller control the positive voltage conversion apparatus and the negative voltage conversion apparatus to change output voltages when output power remains unchanged, so that the neutral wire current meets the preset current range.

Described herein are power conversion systems and related techniques which utilize a coupled split path (CSP) circuit architecture. The CSP structure combines switches, capacitors and magnetic elements in such a way that power is processed in multiple coupled split paths in a variety of voltage domains. These techniques are well suited for power conversion applications that have one or more input/output ports that have a wide voltage range, or if the application is interfacing with the ac line voltage and requires power-factor correction.

Described herein are power conversion systems and related techniques which utilize a coupled split path (CSP) circuit architecture. The CSP structure combines switches, capacitors and magnetic elements in such a way that power is processed in multiple coupled split paths in a variety of voltage domains. These techniques are well suited for power conversion applications that have one or more input/output ports that have a wide voltage range, or if the application is interfacing with the ac line voltage and requires power-factor correction.

A power control apparatus for a distributed power supply interconnected with a power system includes: a conversion circuit that performs reverse conversion of converting power supplied from the distributed power supply from direct current to alternating current and outputting the converted power; and a control device that controls the conversion circuit. The control device changes a target value of received power at a power reception point of the power system on the basis of a predicted value of a power generation amount of the distributed power supply and a predicted value of power consumption of a demand facility, and controls an output of the conversion circuit such that the received power at the power reception point becomes a target value.

A power control apparatus for a distributed power supply interconnected with a power system includes: a conversion circuit that performs reverse conversion of converting power supplied from the distributed power supply from direct current to alternating current and outputting the converted power; and a control device that controls the conversion circuit. The control device changes a target value of received power at a power reception point of the power system on the basis of a predicted value of a power generation amount of the distributed power supply and a predicted value of power consumption of a demand facility, and controls an output of the conversion circuit such that the received power at the power reception point becomes a target value.

Disclosed is a novel and innovative class of buck-boost bidirectional inverters achieve ultra high efficiency in applications requiring converting of one or more low and variable DC voltages of one or more power sources (which may include a battery, a low-voltage DC source, or a set of PV solar panels) to an AC voltage (e.g., connected to a grid) through a single-stage power conversion with step modulation.

Disclosed is a novel and innovative class of buck-boost bidirectional inverters achieve ultra high efficiency in applications requiring converting of one or more low and variable DC voltages of one or more power sources (which may include a battery, a low-voltage DC source, or a set of PV solar panels) to an AC voltage (e.g., connected to a grid) through a single-stage power conversion with step modulation.

A voltage source converter (VSC) system of a high-voltage direct current (HVDC) system is disclosed. The system includes a number of line-commutated converter (LCC) transformers. Each LCC transformer is operable to transform alternate current (AC) voltage. A number of VSC converter units are connected in series and coupled to the plurality of LCC transformers. Each VSC converter unit is operable to convert between the AC voltage and direct current (DC) voltage. A bypass breaker is connected in parallel with at least one of the VSC converter units and operable to be closed to bypass the at least one VSC converter unit.

A charging device according to an exemplary embodiment of the present invention may include: a battery adapted and configured to store a DC voltage, first and second motors adapted and configured to operate as a motor or a generator, first and second inverters adapted and configured to operate the first and second motors, a voltage transformer adapted and configured to boost the DC voltage of the battery to supply it to the first and second inverters and boosts the DC voltage of the inverter to supply it to the battery, and a charging controller adapted and configured to operate the first and second inverters as a booster or operate the voltage transformer as a buck booster according to a voltage that is input through a neutral point of the first and second motors and the voltage of the battery.