The present invention relates to a unit current transformer device and a magnetic induction power supplying device, and particularly to a magnetic induction power supply unit capable of linearly adjusting output power according to the number of unit current transformer devices configured to have a specific resonance frequency. To this end, the unit current transformer device includes a current transformer inducing secondary current from primary current flowing through a line in a magnetic induction manner and having a resonant frequency double or greater than that of the primary current, and a converting unit converting an output of the current transformer to DC power.

An AC power converter converts power from an AC power source to an AC load. A DC power holding source is coupled to an input half-bridge switch, a common half-bridge switch and an output half-bridge switch. A controller is coupled to at least two of the input half-bridge switch, the common half-bridge switch, and an output half-bridge switch. The controller switches the input half bridge at the first switching frequency in boost mode and at the line frequency in buck mode. The controller also switches the output half bridge switch at the first switching frequency in buck mode and at the line frequency in boost mode. Input and output low pass filters can eliminate switching frequency energy from entering the AC source and load. The converter maintains a DC power holding source voltage slightly above peak AC input voltage and significantly less than twice the peak AC input voltage.

We describe a power conditioning unit with maximum power point tracking (MPPT) for a dc power source, in particular a photovoltaic panel. A power injection control block has a sense input coupled to an energy storage capacitor on a dc link and controls a dc-to-ac converter to control the injected mains power. The power injection control block tracks the maximum power point by measuring a signal on the dc link which depends on the power drawn from the dc power source, and thus there is no need to measure the dc voltage and current from the dc source. In embodiments the signal is a ripple voltage level and the power injection control block controls an amplitude of an ac current output such that an amount of power transferred to the grid mains is dependent on an amplitude of a sinusoidal voltage component on the energy storage capacitor.

A power conditioner is provided that includes a heat dissipating member, multiple circuit boards, and a mounting auxiliary plate. A power conditioner circuit including an electric heat generating element is formed on each of the circuit boards. The circuit boards are mounted on a front surface of the heat dissipating member. Heat dissipating fins are arranged on a back surface of the heat dissipating member. Preferably, the heat dissipating member is formed from a material having high heat dissipation property. The mounting auxiliary plate is fixed to the back surface side of the heat dissipating member and provided with a through hole for mounting to a wall. The mounting auxiliary plate has higher rigidity than the heat dissipating member.

The invention relates to a differential mode and common mode choke comprising: a ferromagnetic core comprising three branches (1, 2, 3) extending between a bottom part (5) and a top part (4), a first coil (b1) wound around the first lateral branch (1), a second coil (b3) wound around the second lateral branch (3), the first lateral branch (1) being separated from the top part (4) by a first air gap (e1) and from the bottom part (5) by a second air gap (e10), the second lateral branch (3) being separated from the top part (4) by a first air gap (e3) and from the bottom part (5) by a second air gap (e30), the central branch (2) being separated from the top part (4) by a first air gap (e2) and from the bottom part (5) by a second air gap (e20).

A power conversion system includes one or more power conversion devices coupled to a grid connection. Each of the power conversion devices includes a power converter for converting a first multiphase current provided by the grid connection into a second current; a grid side filter coupled between the grid connection and an input of the power converter; a load side filter coupled to an output of the power converter; neutral points of the grid side filter and the load side filter connected together to form a first node; wherein the first node is not directly grounded.

A power conversion system includes one or more power conversion devices coupled to a grid connection. Each of the power conversion devices includes a power converter for converting a first multiphase current provided by the grid connection into a second current; a grid side filter coupled between the grid connection and an input of the power converter; a load side filter coupled to an output of the power converter; neutral points of the grid side filter and the load side filter connected together to form a first node; wherein the first node is not directly grounded.

A converter arrangement comprises first and second modular multilevel converters, Each of the modular multilevel converters comprises two converter branches. Each converter branch comprises a plurality of series-connected converter cells. Each converter cell comprises a cell capacitor and semiconductor switches for connecting and disconnecting the cell capacitor to the converter branch. At least two converter branches of the first modular multilevel converter are connected via first branch connection point and at least two converter branches of the second modular multilevel converter are connected via second branch connection point. The multilevel converters are connected in parallel via a phase connection point for connecting the converter arrangement to a load or a power source, wherein the phase connection point is connected via a first inductance with the first branch connection point and/or via a second inductance with the second branch connection point. At least one of the modular multilevel converters comprises a protection system.

Disclosed herein is a technique for substantially preventing, in a power converter including a boost power factor correction section, the power factor correction section from starting an intermittent operation even if the ripple voltage of its smoothing capacitor has increased. The converter includes: a power factor correction section including a booster circuit boosting an input voltage supplied from a rectifier section and a smoothing capacitor smoothing an output of the booster circuit; and a control section correcting a power factor by controlling the booster circuit. The control section makes correction to the amount of boost of the booster circuit such that an output voltage of the smoothing capacitor does not become lower than the input voltage.

A semiconductor switching string includes a plurality of series-connected semiconductor switching assemblies, each having a main semiconductor switching element that includes first and second connection terminals. The main semiconductor switching element also has an auxiliary semiconductor switching element electrically connected between the first and second connection terminals. Each semiconductor switching assembly also includes a control unit configured to switch on a respective auxiliary semiconductor switching element to selectively create an alternative current path between the first and second connection terminals whereby current is diverted to flow through the alternative current path to reduce the voltage across the corresponding main semiconductor switching element. The or each control unit is further configured to switch on the auxiliary semiconductor switching element when the voltage across the corresponding main semiconductor switching element differs from a voltage reference derived from the voltage across all of the main semiconductor switching elements.