An apparatus includes a plurality of input nodes configured to receive a multiphase alternating current (AC) input signal. The apparatus further includes a plurality of inductors, a neutral terminal, a first plurality of output nodes, and a second plurality of output nodes. The plurality of inductors is coupled to the plurality of input nodes, and the neutral terminal is coupled to the plurality of inductors. The first plurality of output nodes is coupled to the plurality of inductors and is configured to output a first multiphase AC output signal. The second plurality of output nodes is coupled to the plurality of inductors and is configured to output a second multiphase AC output signal.

A system includes a first inverter connected between a dc power source and an input terminal of a first leg of a coupled inductor, a second inverter connected between the dc power source and an input terminal of a second leg of the coupled inductor, a third inverter connected between the dc power source and an input terminal of a third leg of the coupled inductor, and an output filter connected between the coupled inductor and an ac power source, wherein output terminals of the first leg, the second leg and the third leg of the coupled inductor are connected together and further connected to the output filter.

A converter is configured for connecting between a solar cell and an inverter configured to convert direct-current power output from the solar cell into alternating current power, and the converter is configured to increase the potential-to-ground at the negative terminal of the solar cell to greater than the potential-to-ground at the negative terminal of the inverter when outputting the direct-current power generated by the solar cell to the inverter side.

A disclosed intermediate circuit arrangement includes first and second partial circuit boards of identical design having a series circuit of at least two capacitor banks. The partial circuit boards each have a terminal strip having a positive intermediate circuit connection, a negative intermediate circuit connection, and a central connection. The circuit arrangement also includes a connecting circuit board for electrically connecting the respective connections of the terminal strips of the two partial circuit boards to one another. The connecting circuit board is a multi-layer circuit board with two outer metal layers and at least two inner metal layers arranged between the outer metal layers. The outer metal layers have an electric connection between corresponding connections of the terminal strips of the two partial circuit boards, and at least one first metal layer of the inner metal layers has only an electrical connection of the positive intermediate circuit connections of the two partial circuit boards and at least one second metal layer of the inner metal layers has only an electrical connection of the negative intermediate circuits of the two partial circuit boards. The intermediate circuit arrangement can be part of an inverter.

A disclosed intermediate circuit arrangement includes first and second partial circuit boards of identical design having a series circuit of at least two capacitor banks. The partial circuit boards each have a terminal strip having a positive intermediate circuit connection, a negative intermediate circuit connection, and a central connection. The circuit arrangement also includes a connecting circuit board for electrically connecting the respective connections of the terminal strips of the two partial circuit boards to one another. The connecting circuit board is a multi-layer circuit board with two outer metal layers and at least two inner metal layers arranged between the outer metal layers. The outer metal layers have an electric connection between corresponding connections of the terminal strips of the two partial circuit boards, and at least one first metal layer of the inner metal layers has only an electrical connection of the positive intermediate circuit connections of the two partial circuit boards and at least one second metal layer of the inner metal layers has only an electrical connection of the negative intermediate circuits of the two partial circuit boards. The intermediate circuit arrangement can be part of an inverter.

A high-frequency power supply circuit includes an amplifier circuit. In the amplifier circuit, one end of an inductor is connected to a direct-current power supply. One end of a switching element is connected to the other end of the inductor. A parallel capacitor is connected in parallel to the switching element. One end of an LC series circuit is connected to the one end of the switching element. A circuit capacitor is connected between the other end of the LC series circuit and the other end of the switching element. The amplifier circuit amplifies a signal having a unique frequency input to a control terminal of the switching element. The amplifier circuit outputs, to a load, a current having the frequency from a connection point between the other end of the LC series circuit and the circuit capacitor.

In a converter system having an AC/DC converter, and a method for operating a converter system, in which the terminal of the AC/DC converter on the direct-voltage side feeds a series circuit, which has a braking resistor and a controllable switch, the terminal of a DC/AC converter, in particular an inverter, on the direct-voltage side being connected in parallel to the series circuit. The output signal of a voltage-acquisition device is supplied to an evaluation unit, which generates a control signal for the controllable switch. The evaluation unit includes a device for determining the electric power supplied to the braking resistor, in particular from the intermediate circuit, which is determined by the device from the output signal of the voltage-acquisition device, in particular. The output signal of the device is supplied to a controller, in particular a linear controller, and the controller controls its set value toward the output signal of the device. The controller in particular has a linear controller element, in particular a PI controller element or integration element, whose set value, i.e. whose output signal, is forwarded to a difference generator for determining the difference between the set value and the value of the electric power, the set value being supplied, directly or via a limiter, to a parameterizable filter, whose output signal is supplied to a switching element, which in particular generates an output signal for opening or closing the controllable switch as a function of the exceeding or undershooting of a threshold value.

In a converter system having an AC/DC converter, and a method for operating a converter system, in which the terminal of the AC/DC converter on the direct-voltage side feeds a series circuit, which has a braking resistor and a controllable switch, the terminal of a DC/AC converter, in particular an inverter, on the direct-voltage side being connected in parallel to the series circuit. The output signal of a voltage-acquisition device is supplied to an evaluation unit, which generates a control signal for the controllable switch. The evaluation unit includes a device for determining the electric power supplied to the braking resistor, in particular from the intermediate circuit, which is determined by the device from the output signal of the voltage-acquisition device, in particular. The output signal of the device is supplied to a controller, in particular a linear controller, and the controller controls its set value toward the output signal of the device. The controller in particular has a linear controller element, in particular a PI controller element or integration element, whose set value, i.e. whose output signal, is forwarded to a difference generator for determining the difference between the set value and the value of the electric power, the set value being supplied, directly or via a limiter, to a parameterizable filter, whose output signal is supplied to a switching element, which in particular generates an output signal for opening or closing the controllable switch as a function of the exceeding or undershooting of a threshold value.

An inverting apparatus comprises: a DC port; an AC port; five switches; a first capacitor coupled between the first terminal of the second switch and the second terminal of the fourth switch; and a free-wheeling element coupled between the second terminal of the third switch and the second terminal of the fifth switch; wherein the five switches are controlled so that the device can switch among a plurality of operating modes and transmit active or reactive power to a power grid.

The alternating-current power supply device 1 has: an alternating-current generation bridge 10 for obtaining an alternating-current output; PWM control bridges 20, 30, each including two switch components; and a coupling reactor 40 connected to the PWM control bridges 20, 30. The coupling reactor 40 includes: a core 43; and windings 41, 42 which are connected at one end to respective output ends of the PWM control bridges 20, 30 while being coupled with each other via the core 43. The windings 41, 42 are respectively wound in such directions that magnetic fluxes generated in the core 43 cancel each other out.