Aspects are described for hybrid modular multilevel converters that include half-bridge submodules. In some embodiments, a hybrid modular multilevel converter can include a direct current (DC) bus and an alternating current (AC) node. A first arm of the hybrid modular multilevel converter includes a first submodule chain link and a first arm inductor and a second arm includes a second submodule chain link and a second arm inductor. A capacitor connects between a first side of the first arm and a first side of the second arm.

A method for sequentially driving an electrical load includes (a) controlling N switching cells, where each of the N switching cells is electrically coupled to a respective one of N energy elements, such that the N energy elements are electrically coupled in a first topology to drive the electrical load with a first voltage, N being an integer greater than one, and (b) controlling the N switching cells such that N energy elements are electrically coupled in a second topology that is different from the first topology, to drive the electrical load with a second voltage that is different from the first voltage.

A system and method for compensating a faulty switch in a multi-level flying capacitor converter includes a converter capacitor arranged in parallel to an input, a first and second converter switches arranged respectively between first and second ends of the converter capacitor, first and second bypass switches respectively arranged in parallel to the first and second converter switches, wherein operation includes detecting a faulty converter level that includes at least one of the first and second converter switches, discharging all capacitors arranged in parallel to the input of the multi-level converter, wherein all capacitors comprise the converter capacitors and an input capacitor; closing the first and second bypass switches of the faulty converter level; adapting a modulation of the converter switches of the other converter levels; and restarting the multi-level converter.

A converter apparatus includes a string of electrically interconnected modules that includes a first group of modules comprising a first module and a second group of modules comprising a second module. A first screen is connected to a first defined electric potential and is located adjacent the first group of modules and a second screen is connected to a second defined electric potential and is located adjacent the second group of modules. During operation of the converter apparatus a resonance loop is created from the first module via the first and second screens and the second module back to the first module. A damping unit is located in the resonance loop and is set to dampen electromagnetic noise.

There is provided an electrical assembly comprising a converter (20) for connection to an electrical network (40), the converter (20) comprising at least one module (44) including at least one switching element (46) and at least one energy storage device (48), the or each switching element (46) and the or each energy storage device (48) in the or each module (44) arranged to be combinable to selectively provide a voltage source, the electrical assembly including a controller (54) configured to selectively control the switching of the or each switching element (46) in the or each module (44), wherein the electrical assembly includes a sensor (56a) configured for measuring a current of the electrical network (40), wherein the controller (54) and sensor (56a) are configured to operate in coordination to carry out a characterisation of an electrical parameter of the electrical network (40) so that, in use: the controller (54) selectively controls the switching of the or each switching element (46) in the or each module (44) to modify an electrical parameter of the converter (20) so as to modify the current of the electrical network (40); the sensor (56a) measures a resultant modified current of the electrical network (40); and the controller (54) processes the measured resultant modified current of the electrical network (40) so as to characterise the electrical parameter of the electrical network (40).

A power converter arrangement with a modular multi-level converter which includes a series circuit of switch modules which each have a plurality of semiconductor switches and an energy source. Some of the switch modules are of a first type and others of the switch modules are of a second type. During operation, a positive switch module voltage, a negative voltage module voltage, or a null voltage is generated at connection terminals of the switch modules of the first type, and a positive switch module voltage or a null voltage can be generated at connection terminals of the switch modules of the second type. The power converter arrangement further contains a support structure having a number of levels, which each have receptacles in which the switch modules are arranged, with both switch modules of the first and second type being arranged in each level of the support structure.

A power converter arrangement with a modular multi-level converter which includes a series circuit of switch modules which each have a plurality of semiconductor switches and an energy source. Some of the switch modules are of a first type and others of the switch modules are of a second type. During operation, a positive switch module voltage, a negative voltage module voltage, or a null voltage is generated at connection terminals of the switch modules of the first type, and a positive switch module voltage or a null voltage can be generated at connection terminals of the switch modules of the second type. The power converter arrangement further contains a support structure having a number of levels, which each have receptacles in which the switch modules are arranged, with both switch modules of the first and second type being arranged in each level of the support structure.

Embodiments of this application disclose an inverter apparatus and an inverter apparatus control method. The inverter apparatus includes an inverter circuit and a control unit, and the control unit detects a driving mode of the inverter circuit based on a running state of the inverter circuit. When the inverter circuit outputs reactive power and an output current amplitude is greater than a current threshold, the control unit controls the inverter circuit in a full-bridge two-level bipolar control mode; and in other cases, the control unit controls the inverter circuit in a three-level control mode. This reduces a risk of breaking down horizontal bridge semiconductor switching devices by a voltage spike in an active turn-off process.

Embodiments of this application disclose an inverter apparatus and an inverter apparatus control method. The inverter apparatus includes an inverter circuit and a control unit, and the control unit detects a driving mode of the inverter circuit based on a running state of the inverter circuit. When the inverter circuit outputs reactive power and an output current amplitude is greater than a current threshold, the control unit controls the inverter circuit in a full-bridge two-level bipolar control mode; and in other cases, the control unit controls the inverter circuit in a three-level control mode. This reduces a risk of breaking down horizontal bridge semiconductor switching devices by a voltage spike in an active turn-off process.

A power device may have at least two capacitors in series with each other and in parallel with a DC power source. The power device may have at least a first converter that has at least a controller configured to balance a voltage of the at least two capacitors. The power device may have at least a second converter connected to the at least two capacitors. The second converter may have at least three input conductors, each connected to a terminal of the at least two capacitors. The second converter may have at least two output conductors. The second converter may have at least a switching circuit between the at least three input conductors and at least two output conductors. The second converter may have at least a controller configured to operate the switching circuit. The second converter may passively preserve the voltage balance between the at least two capacitors.