Embodiments of the present application disclose a multi-level inverter clamping modulation method and apparatus, and an inverter. Switching elements of an inverter are controlled when an output voltage of the inverter crosses zero, and switching elements in each inverter bridge arm of an active clamp multi-level inverter include an internal tube, an external tube, and a clamping tube. The internal tube and the external tube are connected in series between a positive bus and a negative bus, the clamping tube is connected between a common terminal of the internal tube and the external tube and a bus, the internal tube is a low-frequency switching element, and the external tube and the clamping tube are high-frequency switching elements.

Embodiments of the present application disclose a multi-level inverter clamping modulation method and apparatus, and an inverter. Switching elements of an inverter are controlled when an output voltage of the inverter crosses zero, and switching elements in each inverter bridge arm of an active clamp multi-level inverter include an internal tube, an external tube, and a clamping tube. The internal tube and the external tube are connected in series between a positive bus and a negative bus, the clamping tube is connected between a common terminal of the internal tube and the external tube and a bus, the internal tube is a low-frequency switching element, and the external tube and the clamping tube are high-frequency switching elements.

The resin material 336 is arranged in a first region 421 surrounded by the fin base 440, the inclined portion 343 of the cover member 340, and the outermost peripheral heat dissipation fins 334 arranged on the outermost peripheral side. Then, the resin material 336 is caused to protrude to the first region 421. That is, the resin material 336 is arranged in the first region 421. In a cross section perpendicular to the refrigerant flow direction (Y direction), a cross-sectional area of the first region 421 is larger than an average cross-sectional area 423 of the adjacent heat dissipation fins 331. Then, a cross-sectional area of a second region 422 formed between the resin material 336 arranged in the first region 421 and the outermost peripheral heat dissipation fin 334 arranged on the outermost peripheral side is smaller than the average cross-sectional area 423 of the heat dissipation fins.

A power converter for transforming electrical power between direct current power and alternating current power is provided, as well as related methods and systems. The power converter comprises: a half-bridge inverter, a switching cell, and a connection branch connecting the half-bridge inverter to the switching cell. The half-bridge inverter comprises: first and second switches connected in parallel, and a first capacitor connected between the first and second switches. The switching cell comprises: a first pair of switches forming a first branch, a second pair of switches and a second capacitor forming a second branch; and a third capacitor connected between the first and second branches. The connection branch is coupled to the half-bridge inverter at a first point intermediate the first capacitor and the second switch, and coupled to the switching cell at a second point intermediate the first branch and the second capacitor.

A power converter for transforming electrical power between direct current power and alternating current power is provided, as well as related methods and systems. The power converter comprises: a half-bridge inverter, a switching cell, and a connection branch connecting the half-bridge inverter to the switching cell. The half-bridge inverter comprises: first and second switches connected in parallel, and a first capacitor connected between the first and second switches. The switching cell comprises: a first pair of switches forming a first branch, a second pair of switches and a second capacitor forming a second branch; and a third capacitor connected between the first and second branches. The connection branch is coupled to the half-bridge inverter at a first point intermediate the first capacitor and the second switch, and coupled to the switching cell at a second point intermediate the first branch and the second capacitor.

A semiconductor module includes a first power semiconductor device, a conductive wire, and a resin film. The conductive wire is joined to a surface of a first front electrode of the first power semiconductor device. The resin film is formed to be continuous on at least one of an end portion or an end portion of a first joint between the first front electrode and the conductive wire in a longitudinal direction of the conductive wire, a surface of the first front electrode, and a surface of the conductive wire. The resin film has an elastic elongation rate of 4.5% to 10.0%.

A semiconductor module includes a first power semiconductor device, a conductive wire, and a resin film. The conductive wire is joined to a surface of a first front electrode of the first power semiconductor device. The resin film is formed to be continuous on at least one of an end portion or an end portion of a first joint between the first front electrode and the conductive wire in a longitudinal direction of the conductive wire, a surface of the first front electrode, and a surface of the conductive wire. The resin film has an elastic elongation rate of 4.5% to 10.0%.

Each cell of a cell assembly for a converter may include: first and second terminals, switching elements, and a capacitor. The cells are connected in series such that, for each pair of neighbouring cells, the first terminal of a first cell is connected to the second terminal of a second cell. Each cell includes a bypass connected to the first and second terminals that bypasses switching elements in a short circuit configuration and does not bypass the switching elements in an open circuit configuration. Each cell has a cell controller providing control signals to the sw itching elements to connect the capacitor to the first and second terminals or to bypass the capacitor. The cell controller provides a control signal to the bypass unit of neighbouring cells to change its configuration between the short circuit and open circuit configurations.

A motor drive system includes a direct current (DC) bus that provides a DC link voltage across a DC link capacitor, and a split DC link mid-point circuit connected in parallel with the DC link capacitor. The split DC link mid-point circuit establishes a mid-point reference based on the DC link voltage. A power inverter is in signal communication with the DC bus. The power inverter includes one or more gate driver units configured to drive one or more corresponding switches. Each gate driver unit includes a mid-point ground connection that is connected to the mid-point reference. The split DC link mid-point circuit can define a voltage divide that establishes the mid-point reference and can be used to monitor the DC link voltage.

A semiconductor device includes first and second electrodes, a semiconductor part therebetween, and a control electrode between the semiconductor part and the first electrode. The semiconductor part includes first, third and fifth layers of a first conductivity type and second and fourth layers of a second conductivity type. The second layer is provided between the first layer and the first electrode. The third layer is provided between the second layer and the first electrode. The fourth layer and the fifth layer are selectively provided between the first layer and the second electrode. In a method for controlling the semiconductor device, first to third voltages are applied in order to the control electrode while a p-n junction between the first and second layers is biased in a forward direction. The second and third voltages are greater than the first voltage, and the third voltage is less than the second voltage.