A transformer system includes: a main transformer including a primary winding coupled to AC mains and a secondary winding; a load circuit including a load switch configured to be coupled to a load, the load circuit being coupled to the secondary winding of the main transformer; an auxiliary power supply coupled to AC mains; a controller coupled to an output of the auxiliary power supply; an electronic switch between the AC mains and the primary winding of the main transformer and configured to be controlled by the controller; and a load detector coupled to the load circuit and configured to detect whether the load is connected to the main transformer and to output a load signal to the controller in accordance with whether or not the load is connected to the main transformer, wherein the controller is configured to control the electronic switch in accordance with the load signal.

A transformer unit and a power converter circuit are provided. The transformer unit includes: a first secondary wiring layer including a first secondary winding; a second secondary wiring layer adjacent to the first secondary wiring layer and including a second secondary winding, a first end of the second secondary winding being connected to a first end of the first secondary winding via at least one first via hole; and a plurality of primary wiring layers including a primary winding, the first secondary wiring layer and the second secondary wiring layer being disposed between the plurality of primary wiring layers, wherein at least one of the first via hole is disposed within a projection of the primary winding in the plurality of primary wiring layers.

A transformer unit and a power converter circuit are provided. The transformer unit includes: a first secondary wiring layer including a first secondary winding; a second secondary wiring layer adjacent to the first secondary wiring layer and including a second secondary winding, a first end of the second secondary winding being connected to a first end of the first secondary winding via at least one first via hole; and a plurality of primary wiring layers including a primary winding, the first secondary wiring layer and the second secondary wiring layer being disposed between the plurality of primary wiring layers, wherein at least one of the first via hole is disposed within a projection of the primary winding in the plurality of primary wiring layers.

A motor drive of an embodiment of the present invention includes a PWM converter for converting AC power inputted from a low voltage AC power source into DC power by PWM control, an inverter for converting the received DC power to AC power to drive a motor, and a capacitor connected between the PWM converter and the inverter. The PWM converter is operated so as to limit input and output currents or input and output power to predetermined values, and supplied from the low voltage AC power source with a lower voltage than a voltage required to drive the motor. The PWM converter boosts a DC link voltage being an output voltage to the voltage able to drive the motor, and thereby serves to increase the potential difference of the capacitor between charged and discharged states to reduce the capacitance of the capacitor.

The disclosure relates to a balancing system for a network. The system includes a network input for detecting balancing requirements, and a transformer that includes a first winding connected to the output of the network input. The system also includes an inverter connected to a second winding of the transformer, a set of batteries connected to the inverter, and a supervision unit configured to activate the inverter and to charge or discharge the batteries when an imbalance is measured on said network. The system further includes an additional inverter connected to a third winding of the transformer, the output of which is used to supply power to at least one charging socket of an electric vehicle. The supervision unit is configured to activate the additional inverter when a charging requirement is detected at the charging socket and the requirements for injection into the network are less than a threshold value.

The disclosure relates to a balancing system for a network. The system includes a network input for detecting balancing requirements, and a transformer that includes a first winding connected to the output of the network input. The system also includes an inverter connected to a second winding of the transformer, a set of batteries connected to the inverter, and a supervision unit configured to activate the inverter and to charge or discharge the batteries when an imbalance is measured on said network. The system further includes an additional inverter connected to a third winding of the transformer, the output of which is used to supply power to at least one charging socket of an electric vehicle. The supervision unit is configured to activate the additional inverter when a charging requirement is detected at the charging socket and the requirements for injection into the network are less than a threshold value.

A power converter includes an arm in which a plurality of converter cells are connected in series, each of the converter cells including at least two switching elements, a power storage element and a pair of output terminals. A control device controls the power converter. The converter cell includes a switch to have the converter cell bypassed. When the control device senses failure of the converter cell, it has the failed converter cell bypassed, estimates an output voltage lost by bypassing the failed converter cell, and has a normal converter cell supply the estimated output voltage of the failed converter cell.

Systems and methods for efficient power conversion in a power supply in a power distribution system are disclosed. In particular, a low frequency transformer having high conversion efficiency is coupled to an input from a power grid. An output from the transformer is rectified and then converted by a power factor correction (PFC) converter before passing the power to the distributed elements of the power distribution system. By placing the transformer in front of the PFC converter, overall efficiency may be improved by operating at lower frequencies while preserving a desired power factor and providing a desired voltage level. The size and cost of the cabinet containing the power conversion circuitry is minimized, and operating expenses are also reduced as less waste energy is generated.

A transformer for adjusting the voltage supplied to a load, the transformer comprising a primary winding connectable to a primary AC electrical supply and a secondary winding connectable in series between a live supply and a load. The primary winding comprises a switching means operable to change the number of turns of the primary winding connectable to the primary AC electrical supply where the number of turns of the primary winding connectable to the primary AC electrical supply is greater than a number of turns in the secondary winding. The switching means comprises one or more solid state switches.

A transformer for adjusting the voltage supplied to a load, the transformer comprising a primary winding connectable to a primary AC electrical supply and a secondary winding connectable in series between a live supply and a load. The primary winding comprises a switching means operable to change the number of turns of the primary winding connectable to the primary AC electrical supply where the number of turns of the primary winding connectable to the primary AC electrical supply is greater than a number of turns in the secondary winding. The switching means comprises one or more solid state switches.