A high-power motor controlled by parallelly connected windings is provided. The motor comprises multi-phase windings. Each phase includes n winding branches and 2n power devices, wherein the n winding branches are connected in parallel with each other, and each winding branch is independently controlled by a power device.

A method provides current limitation in the event of transient voltage variations at an AC output of a multilevel inverter that includes a bridge circuit with a first DC input, a second DC input, a neutral terminal and a bridge output, as well as a line filter with a choke connected between the bridge output and the AC output, and a capacitor connected between the AC output and the neutral terminal. In the method, depending on the voltage at the capacitor, when a first current threshold is exceeded by the choke current, a regular operating mode is interrupted and measures for current limitation are initiated. A multilevel inverter is further disclosed including a control circuit that is configured to carry out such a method.

An apparatus for controlling a power converter includes a controller configured to detect an error in an output voltage of the power converter at a zero-crossing of a cyclically varying input signal and a compensator coupled to the controller and the power converter and configured to regulate the output voltage of the power converter in response to the error.

A multilevel power converter and method for transforming DC power from a DC source into AC power for an AC load are provided. The converter is composed of a half-bridge inverter, a switching cell, and a controller configured for controlling operation of the half-bridge inverter and the switching cell. The half-bridge inverter and the switching cell are connectable to the DC source and the AC load. The switching cell is composed of first and second pairs of switches forming first and second branches in parallel, first and second capacitors connected in series in a capacitor branch connected between the first and second branches, and a pair of back-to-back connected switches in a third branch, the third branch connected to the capacitor branch and connectable to the AC load.

A power conversion device includes: a first control unit and a second control unit that output a first control signal and a second control signal, respectively; a gate circuit that causes a control signal selected from the first control signal and the second control signal to pass through the gate circuit; and a drive circuit that drives a main circuit based on the control signal that passes through the gate circuit. When the second control signal is selected in the state where the first control signal passes through the gate circuit, the gate circuit interrupts the first control signal and causes the second control signal to pass through the gate circuit as an absolute value of an instantaneous value of an AC current decreases below a threshold current.

A power conversion device includes: a first control unit and a second control unit that output a first control signal and a second control signal, respectively; a gate circuit that causes a control signal selected from the first control signal and the second control signal to pass through the gate circuit; and a drive circuit that drives a main circuit based on the control signal that passes through the gate circuit. When the second control signal is selected in the state where the first control signal passes through the gate circuit, the gate circuit interrupts the first control signal and causes the second control signal to pass through the gate circuit as an absolute value of an instantaneous value of an AC current decreases below a threshold current.

This application relates to a cell (1200) or sub-module for a voltage source converter (1201). The cell includes an energy storage apparatus (101; 101a, 101b) and a plurality of dual-switch semiconductor packages (201), each having first and second semiconductor switches (202, 203) connected in series. The cell is operable in an active state in which an energy storage apparatus (101; 101a, 101b) is electrically connected in series between cell terminals (102a, 102b) and a bypass state in the cell terminals (102a, 102b) are electrically connected via a path that bypasses the first energy storage apparatus. The plurality of dual-switch semiconductor switch packages are configured to provide a first set of semiconductor switches (301; 401) connected between nodes of the cell that are electrically connected in the first active state and electrically disconnected in the first bypass state; and a second set of semiconductor switches (302a, 302b; 402a, 402b) is connected between nodes of the cell that are electrically disconnected in the first active state and electrically connected in the bypass state. The second set of switches comprises a greater number of switches in parallel than the first set of switches.

This application relates to a cell (1200) or sub-module for a voltage source converter (1201). The cell includes an energy storage apparatus (101; 101a, 101b) and a plurality of dual-switch semiconductor packages (201), each having first and second semiconductor switches (202, 203) connected in series. The cell is operable in an active state in which an energy storage apparatus (101; 101a, 101b) is electrically connected in series between cell terminals (102a, 102b) and a bypass state in the cell terminals (102a, 102b) are electrically connected via a path that bypasses the first energy storage apparatus. The plurality of dual-switch semiconductor switch packages are configured to provide a first set of semiconductor switches (301; 401) connected between nodes of the cell that are electrically connected in the first active state and electrically disconnected in the first bypass state; and a second set of semiconductor switches (302a, 302b; 402a, 402b) is connected between nodes of the cell that are electrically disconnected in the first active state and electrically connected in the bypass state. The second set of switches comprises a greater number of switches in parallel than the first set of switches.

The grid interconnection system is provided with a switching unit configured to switch a connection destination of an interconnection terminal of a first power conditioner and a load, between a power grid and a self-standing terminal of a second power conditioner, and a connection controller configured to execute, on the switching unit, first control for connecting the power grid to the interconnection terminal of the first power conditioner and the load in a non-power outage of the power grid, and second control for connecting the self-standing terminal of the second power conditioner to the interconnection terminal of the first power conditioner and the load in a power outage of the power grid.

The present disclosure discloses a hybrid five-level bidirectional DC/DC converter and a voltage match modulation method thereof. The converter includes a first input filter capacitor C.sub.inp and a second input filter capacitor C.sub.inn, an output filter capacitor C.sub.o, a DC voltage source, a primary-side hybrid five-level unit, a primary-side two-level half bridge, a secondary-side single-phase full bridge H2, a high-frequency isolation transformer M.sub.1, a high-frequency inductor L.sub.s, and a controller. A positive pole of a DC bus of the primary-side hybrid five-level unit is coupled to a positive pole of the corresponding DC voltage source and to a positive pole of the input filter capacitor C.sub.inp respectively. A negative pole of the DC bus of the primary-side hybrid five-level unit is coupled to a negative pole of the corresponding DC voltage source and to a negative pole of the input filter capacitor C.sub.inn respectively. A terminal of the primary-side hybrid five-level unit is coupled to a midpoint between the first input filter capacitor C.sub.inp and the second input filter capacitor C.sub.inn connected in series. The primary-side hybrid five-level unit is coupled to a primary side of the high-frequency isolation transformer M.sub.1 through the high-frequency inductor L.sub.s, and a midpoint of the primary-side two-level half bridge is coupled to another terminal of the primary side of the high-frequency transformer.