The invention provides a series resonant LLC power converter unit to provide a plurality of power outputs. The power converter unit comprises a plurality of transformers arranged such that at least one primary winding of each transformer is connected in parallel and configured to provide a power output. An inductive element is positioned in parallel with at least one primary winding selected from said plurality of transformers, wherein the inductive element restricts variation in inductance for said plurality of transformers and power outputs in operation.

The present invention provides a multi-active bridge converter. The converter comprises n multi-active bridges, wherein each of the n multi-active bridges comprises a DC/AC bridge, a single-phase transformer and m AC/DC bridges, where n is greater than or equal to 3, and m is greater than or equal to 1; the single-phase transformer is provided with one primary winding and m secondary windings; the DC/AC bridge is configured to receive a DC input signal, and AC output terminals of the DC/AC bridge are connected to the primary winding of the single-phase transformer; one terminal of the i.sup.th secondary winding among the m secondary windings of the single-phase transformer is connected to an AC input terminal of the i.sup.th AC/DC bridge among the m AC/DC bridges, the other terminal of the i.sup.th secondary winding is connected to the other terminals of the i.sup.th secondary windings among m secondary windings of single-phase transformers in the remaining (n−1) multi-active bridges, where i is greater than or equal to 1 and less than or equal to m; and positive busbars DC+ and negative busbars DC− of the DC output terminals of all the AC/DC bridges among the n multi-active bridges are respectively connected with each other to serve as DC output terminals of the multi-active bridge converter.

Power isolators for providing electrical isolation between an input port and an output port that exhibit low electromagnetic interference (EMI) are described. The low EMI may be achieved by, for example, canceling out a common mode current across a transformer in the power isolator that may be converted into EMI. The power isolator may include at least one oscillator circuit that is configured to apply a first signal to a first transformer and a second, different signal to a second transformer. The first and second signals may be configured such that the common mode current generated in each of the first and second transformers has an opposite direction. Thus, the common mode currents in the first and second transformers may at least partially cancel out. As a result, the EMI exhibited by the power isolator may be reduced.

The present disclosure provides a circuits for harvesting energy from an energy source. The energy source may have a first and a second potential of an input voltage. The circuits may further comprise one or more of a charging capacitor, transformers, transistors, or diodes. The circuits may be used for harvesting energy from thermoelectric generators.

The present invention relates to a magnetic resonance charging system comprising a voltage source (1) and an inverter (2), said inverter (2) comprising a parallel LC inverter resonant circuit (3) and at least one charging plate (4), characterized in that said inverter resonant circuit (3) comprises a capacitor (32) connected in parallel to a primary winding (33) of said at least one charging plate (4) and in that said inverter (2) further comprises: a measuring means (5) for measuring the instantaneous voltage across said inverter resonant circuit (3), a phase shifter (6) connected to said measuring means (5) an excitation means (7) connected to the phase shifter (6), able to inject energy from said voltage source (1) into the inverter resonant circuit (3) during each cycle observed by the measuring means (5), with a phase shift indicated by the phase shifter (6).

The present invention also relates to a method of operating a charging system according to the invention.

A power converter is provided. The power converter includes power units and local controller. Input terminals of the power units are connected to each other in series. Output terminals of the plurality of power units are connected to each other in parallel. The local controllers are electrically connected to the power units respectively. Each local controller controls an operation of switching devices in the corresponding power unit. Each local controller receives an input capacitor voltage on an input capacitor of the corresponding power unit, an input reference voltage and an output voltage of the power converter. In each power unit and the corresponding local controller, when an input difference between the input reference voltage and the input capacitor voltage is smaller than a first set value, the local controller controls a switching frequency of the switching devices in the corresponding power unit to jump to a preset frequency.

A magnetic device includes a magnetic core assembly, a first secondary winding, a second secondary winding and a primary winding. The magnetic core assembly includes a first magnetic leg, a second magnetic leg and a third magnetic leg. The first to third magnetic legs are arranged in sequence. The second magnetic leg is disposed between the first magnetic leg and the third magnetic leg. The first secondary winding is disposed between the first magnetic leg and the second magnetic leg, and the second secondary winding is disposed between the second magnetic leg and the third magnetic leg. A first terminal of the primary winding is disposed between the first magnetic leg and the second magnetic leg, and a second terminal of the primary winding is disposed between the second magnetic leg and the third magnetic leg.

The system proposed in this invention allows the conversion of energy from an AC/DC source, located on a platform (surface) and transmitted through an umbilical to a robot that operates on flexible lines, converting the electrical voltage to levels suitable for supplying the robotic system, and can also be used for supplying other pieces of equipment that operate with low voltage and require power high-density and protection against voltage transients.

The system of the invention consists of a surface source (2), fed by the platform's three-phase grid (1), an umbilical cable (3), which connects the source to the robot, an overvoltage protection circuit (4), and a two-stage conversion modular system (5 and 6).

Disclosed are a transformer, and a power conversion apparatus or a photovoltaic module including the same. The transformer includes a first core including a base, a first protrusion member to protrude from the base, and a first external wall spaced apart from the first protrusion member and to surround the first protrusion member, a first winding wound in the first core, a second core including a second base, a second protrusion member to protrude from the second base, and a second external wall spaced apart from the second protrusion member and to surround the second protrusion member, a second winding wound in the second core, and a barrier rib configured to separate the first winding and the second winding from each other. Thus, ease of processing is achieved and radiation of electromagnetic noise is reduced.

The invention relates to a control device (100) for a DC-DC converter (110) having multiple parallel-connected DC-DC converter modules (120_1, . . . , 120_n). The control device measures individual target current values for the DC-DC converter modules so that these are operated with a common degree of utilisation.