A basic unit for a power converter, a power converter, and a universal power interface are disclosed. The basic unit includes an inductor, a power half-bridge, a first terminal, a second terminal, a third terminal, and a fourth terminal, where an end of the inductor is connected to a midpoint of the power half-bridge, and the other end of the inductor is connected to the first terminal; a source terminal of a lower bridge arm of the power half-bridge is connected to the second terminal and the fourth terminal; and a drain terminal of an upper bridge arm of the power half-bridge is connected to the third terminal. The manufacturing costs of a microgrid system and the difficulty of later maintenance can be reduced.

The invention relates to a converter assembly comprising at least two converters (7, 7ʹ) and a control unit (1) connected to the converters (7, 7ʹ), wherein the control unit (1) is designed, continuously or at discrete time intervals, to transmit to the converters (7, 7ʹ) their permissible electrical power range, in particular their minimum power value P.sub.min and/or their maximum power value P.sub.max, to determine the current power balance of the individual converters (7, 7ʹ) or to receive it from same, and to adjust the permissible electrical power range of the converters (7, 7ʹ) in such a way that the power balance of the entire converter assembly does not leave a predefined range. The invention also relates to a method for operating a converter assembly of this type.

A resonant inverter includes first and second switches, first and second capacitive elements, a first coil, a second coil, a third coil, and a third capacitive element. The first and second switches are alternately turned on and off. The first and second capacitive elements are connected in parallel to the first switch and the second switch, respectively. The first coil is disposed between the first switch and an input voltage terminal. The second coil is disposed between the second switch and the input voltage terminal. The third coil and a third capacitive element are connected in series to each other and connected in parallel to a series circuit of the first and second coils. The first and second capacitive elements and the first and second coils constitute a plurality of first resonant circuits. The third coil and the third capacitive element constitute a single second resonant circuit.

A resonant inverter includes first and second switches, first and second capacitive elements, a first coil, a second coil, a third coil, and a third capacitive element. The first and second switches are alternately turned on and off. The first and second capacitive elements are connected in parallel to the first switch and the second switch, respectively. The first coil is disposed between the first switch and an input voltage terminal. The second coil is disposed between the second switch and the input voltage terminal. The third coil and a third capacitive element are connected in series to each other and connected in parallel to a series circuit of the first and second coils. The first and second capacitive elements and the first and second coils constitute a plurality of first resonant circuits. The third coil and the third capacitive element constitute a single second resonant circuit.

Positive electrode-side input terminal is connected to first positive electrode-side battery terminal, negative electrode-side input terminal is connected to second negative electrode-side battery terminal, a switch is connected between first negative electrode-side battery terminal and second positive electrode-side battery terminal, between second positive electrode-side battery terminal and first connection point between positive electrode-side input terminal and first positive electrode-side battery terminal, and between first negative electrode-side battery terminal and second connection point between negative electrode-side input terminal and second negative electrode-side battery terminal, positive electrode-side output terminal is connected to positive electrode-side converter output terminal, negative electrode-side output terminal is connected to negative electrode-side converter output terminal, positive electrode-side converter input terminal is connected to a line connecting positive electrode-side input terminal and first positive electrode-side battery terminal, and negative electrode-side converter input terminal is connected to a line connecting negative electrode-side input terminal and second negative electrode-side battery terminal.

Positive electrode-side input terminal is connected to first positive electrode-side battery terminal, negative electrode-side input terminal is connected to second negative electrode-side battery terminal, a switch is connected between first negative electrode-side battery terminal and second positive electrode-side battery terminal, between second positive electrode-side battery terminal and first connection point between positive electrode-side input terminal and first positive electrode-side battery terminal, and between first negative electrode-side battery terminal and second connection point between negative electrode-side input terminal and second negative electrode-side battery terminal, positive electrode-side output terminal is connected to positive electrode-side converter output terminal, negative electrode-side output terminal is connected to negative electrode-side converter output terminal, positive electrode-side converter input terminal is connected to a line connecting positive electrode-side input terminal and first positive electrode-side battery terminal, and negative electrode-side converter input terminal is connected to a line connecting negative electrode-side input terminal and second negative electrode-side battery terminal.

A gate drive circuit includes first and second transistors for turning on and off semiconductor switching devices. The circuit includes a DC power supply for driving the first and second transistors. The gate drive circuit further includes a third transistor, a fourth transistor, and a DC power supply being a power supply for the third and fourth transistors with a voltage value lower than the voltage value of the DC power supply, thereby making lower the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the third transistor than the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the first transistor.

A gate drive circuit includes first and second transistors for turning on and off semiconductor switching devices. The circuit includes a DC power supply for driving the first and second transistors. The gate drive circuit further includes a third transistor, a fourth transistor, and a DC power supply being a power supply for the third and fourth transistors with a voltage value lower than the voltage value of the DC power supply, thereby making lower the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the third transistor than the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the first transistor.

Aspects of interface converter common mode (CM) voltage control are described. In one embodiment, a bi-directional alternating current (AC) to direct current (DC) interface converter system includes an AC-DC converter between an AC power system and an interface link and a DC-DC converter between a DC power system and the interface link. The AC-DC converter can include a bridge converter having power switches, such as field-insulated gate bipolar transistors (IGBTs) or another power semiconductor device. The system also includes a control loop that generates control signals for switching the power switches of the AC-DC converter, and a CM control loop that injects a CM control signal into the control loop. By injecting the CM control signal into the control loop, low-frequency ripple and asymmetry between positive and negative output voltages of the DC power system can be reduced.

A gate drive circuit includes first and second transistors for turning on and off semiconductor switching devices. The circuit includes a DC power supply for driving the first and second transistors. The gate drive circuit further includes a third transistor, a fourth transistor, and a DC power supply being a power supply for the third and fourth transistors with a voltage value lower than the voltage value of the DC power supply, thereby making lower the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the third transistor than the impedance of the path of a current flowing from the DC power supply to the gates of the switching devices through the first transistor.