An object of the present disclosure is to provide a trench gate type power semiconductor device that does not easily break even when stress is applied. A SiC-MOSFET includes a SiC substrate, a drift layer of a first conductive type, formed on the SiC substrate, a base region of a second conductivity type formed in a surface layer of the drift layer, a source region of the first conductivity type selectively formed in a surface layer of the base region, a trench extending through the base region and the source region and reaching the drift layer, a gate electrode embedded in the trench and having a V-shaped groove on an upper surface thereof, and an oxide film formed on an upper surface including the groove of the gate electrode, in which a bottom of the V-shape groove is deeper than the base region.

A method for operating an inverter includes applying, via a switching unit of the inverter, an AC voltage to a phase line in which a filter inductor is arranged, determining a coil current (i.sub.L) of the filter inductor and determining a coil voltage (u.sub.L) of the filter inductor, determining a first value (L(I.sub.X)) of the filter inductor for a first value determining an inductance profile of the filter inductor with respect to the coil current, using the determined first value of the filter inductance and optionally using the at least one determined further value of the filter inductance, and controlling the switching unit of the inverter, via a control unit, to generate an alternating current in the phase line. At least one parameter of the control process is continuously adapted to the momentary coil current according to the determined current-dependent inductance profile.

In this semiconductor device, an emitter electrode of a power semiconductor element includes a first sub-electrode provided in a region including a central portion of a front surface of a semiconductor substrate and a second sub-electrode provided in a region not including the central portion of the front surface of the semiconductor substrate. A first bonding wire connects the first sub-electrode and an emitter terminal. A second bonding wire connects the second sub-electrode and the emitter terminal. First and second voltage detectors detect voltages between the emitter terminal and the first and second sub-electrodes, respectively. It is possible to separately detect degradation of both the first bonding wire that degrades in an early period and the second bonding wire that degrades in a terminal period.

The present invention provides a control system for a three-phase inverter, which comprises an instantaneous value voltage controller and an equivalent effective value voltage controller, wherein the instantaneous value voltage controller is configured to feed back and control an instantaneous value of an inverter output voltage, the equivalent effective value voltage controller is configured to perform an orthogonal decomposition feedback control on an effective value of the inverter output voltage, and wherein the equivalent effective value voltage controller is configured to perform integral compensation respectively on a real-axis voltage and an imaginary-axis voltage of a two-phase rotating coordinate system of the three-phase inverter, and an output of the instantaneous value voltage controller and an output of the equivalent effective value voltage controller are used to obtain the inverter output voltage through a delay stage transfer function and a controlled object transfer function. The control system of the present invention has fast regulating speed and high stability.

Provided is a novel multi-level inverter with mixed device types and methods of controlling same. This novel multi-level inverter topology and control method allows the use of high frequency switching devices for controlled PWM switching, while also using lower frequency switching devices for directional switches. This combination of high frequency PWM switching devices with low frequency directional switching devices allows a cost reduction without a significant performance degradation.

A power switching circuit including a first DC/DC converter having a first input configured to receive a first input DC voltage, a second DC/DC converter having a first input configured to receive a second input DC voltage, a DC/AC inverter having a first input coupled to the output of the first DC/DC converter and a second input coupled to the output of the second DC/DC converter, the DC/AC inverter including n (n>2) switching legs, and at least one controller coupled to the first DC/DC converter, the second DC/DC converter, and the DC/AC inverter, the at least one controller configured to operate the DC/AC inverter to provide n AC signals to at least one load coupled to the DC/AC inverter by operating two of the n switching legs in a static state and n−2 of the n switching legs in a transition state.

A method is provided for limiting double-frequency internal power distortion in a power system. The method includes receiving an input voltage from a voltage source at a power converter from which an output power is provided to an electrical load, measuring the output power having a waveform with a steady-state component and a double-frequency transient component, executing computer-readable program code, via processing circuitry, to determine a compensating waveform equal in amplitude to the double-frequency transient component, and that is anti-phase to the double-frequency transient component, and causing the power converter to generate the compensating waveform such that the waveform and the compensating waveform superpose, and the double-frequency transient component of the waveform and the compensating waveform destructively interfere, leaving the steady-state component that is delivered to the electrical load.

An electrical system can include a rechargeable energy storage system (RESS) and a power inverter connected to the RESS. The power inverter can be configured to provide electrical power to a traction motor. The electrical system includes a plurality of machine windings connected between a plurality of first switches and the traction motor. Each switch of the plurality of first switches is configured to transition between a closed state to allow current flow between the power inverter and the traction motor. The electrical system includes a plurality of inductor windings connected between a plurality of second switches and an off-board power source. Each switch of the plurality of second switches is configured to transition between a closed state to allow current flow between the off-board power source and the power inverter to charge the RESS.

The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error Δθv representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ωr of a motor.

A method for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes providing a plurality of switching devices of the power converter in one of a neutral point clamped topology or an active neutral point clamped topology, the plurality of switching devices including a first group and a second group of switching devices. The method also includes providing a multi-state deadtime for the first and second groups of switching devices that changes based on different state transitions of the power converter. Further, the method includes operating the first and second groups of switching devices according to the multi-state deadtime to allow the first group to switch differently than the second group during the different state transitions, thereby decreasing voltage overshoots on the first group during one or more of the different state transitions and providing safe transition between commutation states of the power converter.