The invention relates to a control circuit (1) of an electric motor (4), the control circuit (1) comprising a filtering device (13) in order to filter the high frequencies likely to produce perturbing electromagnetic radiation when the electric motor (4) is driven. To this end, the filtering device (13) comprises a first filtering device (131) branched off from a power bridge (12) driving the electric motor (4), each filtering branch forming the first filtering device (131) being located near the power bridge (12) and/or one of the corresponding power branches (A, B, C) of said power bridge (12) so that a length of an electrical conductor (1313) connecting said filtering branch to said power branch is less than 20 mm. The invention also relates to a motorized-fan unit (8) for motor vehicles comprising such a control circuit (1).

Electrical power conversion systems and methods suited for driving electric motors, and related systems such as propulsion systems, and vehicles employing same, are disclosed herein. In an example embodiment, the electrical power conversion system includes a plurality of series coupled inverters, each including respective first and second DC input terminals and also including respective AC output ports by which the inverters can respectively be coupled at least indirectly to motor winding sets. Additionally, the system includes a controller coupled to the inverters and configured to generate control signals that are respectively provided to the inverters. The control signals tend to cause respective AC output powers output from the respective AC output ports to be equal or substantially equal in a manner that tends to result in respective DC link voltage portions applied between the respective DC input terminals of the respective inverters being or becoming equal or substantially equal.

The present invention discloses a modular intelligent combined wind power converter and a control method thereof. The modular intelligent combined wind power converter comprises separate bridge arm power units, wherein a plurality of the bridge arm power units are connected in parallel to form a high-capacity bridge arm power module, three bridge arm power modules form a three-phase full-controlled bridge power module, and the three-phase full-controlled bridge power module comprises an electric reactor, a capacitor, a fuse and a circuit breaker to form a basic converter module, and the basic converter module forms a high-capacity wind power converter through a modular intelligent combination method.

An inverter includes an N-channel IGBT, with a freewheeling diode, coupled to a phase of an electric machine, and has a MOSFET coupling a local voltage with a gate of the IGBT and configured to transition from saturation to linear operation as a current flow direction through the diode switches from positive to negative while the IGBT initiates a current through the electric machine.

Generalized circuit topology of voltage level multiplier modules (VLMMs) for use with multilevel inverters (MLIs) and power converter circuits comprising at least one VLMM and a MLI are described herein. The VLMM is configured to receive a first output voltage from the MLI having a first number of voltage levels and to generate a second output voltage having a second number of voltage levels. If the first number of voltage levels is M, and the VLMM is N-fold voltage level multiplier, then second number of voltage levels is M×N+1. Switching pattern generators for use with the VLMM and modulation methods for controlling switching elements of the VLMM are also described herein.

The present disclosure provides an inverter control device which estimates back electromotive force of an induction motor, and which uses a torque current and a flux current so as to calculate a slip frequency and compensate for same, thereby enabling the motor to operate at a constant speed. To this end, the present invention may comprise: a command voltage generating unit for outputting, to an inverter, a three phase PWM voltage with respect to a command frequency on the basis of a voltage/frequency operation; and a slip frequency determining unit for determining a slip frequency on the basis of a phase current and a phase voltage of a motor driven by the inverter.

The present invention disclose a method and apparatus for pulse-width modulation (PWM) of a variable-frequency drive (VFD), the method comprising: for each sector of a space vector graph for PWM of the VFD, identifying at least two possible clamping phases in switching between the vectors in the sector; comparing currents in multiple phases in at least one PWM cycle; in the sector of the space vector graph corresponding to the PWM cycle, determining the possible clamping phase with the maximum current in the at least two possible clamping phases; and clamping the determined possible clamping phase with the maximum current.

A converter system and inverter system are disclosed with individual real and reactive power control for each phase of a poly-phase system. The converter system includes a controller, bidirectional single-phase inverters with AC sides coupled to an AC line filter and DC sides connected in parallel to a link capacitor coupled to DC/DC converters. Each inverter handles a separate AC phase. The controller controls the inverters and DC/DC converters so the current amplitude of each AC phase is independent, and the phase difference of each AC phase is independent. The inverters can be galvanically isolated between the DC and AC sides. The inverters can be non-isolated inverters having line and neutral connectors coupled to an isolated transformer winding, and the output windings of the transformer can be wired in a Wye configuration. The inverters can have local controllers.

An inverter controller is configured to control inverters connected in parallel. The inverter controller is configured to closes switch of a first inverter and turn on a first switching element provided at the first inverter to charge capacitors of the inverters at the time of starting the inverters, and to close the other switches after the capacitors are charged.

A power inverter includes a multi-phase inverter circuit electrically connected to positive and negative conductors of the high-voltage bus. A bi-stable switch is electrically connected in series with a discharge resistor between the positive and negative conductors of the high-voltage bus, and a capacitor is electrically connected between the positive and negative conductors of the high-voltage bus. First and second trigger circuits are in communication with a gate of the bi-stable switch, and first and second contactors are controllable to electrically connect a respective one of the positive and negative conductors of the high-voltage bus to the high-voltage DC power source. The bi-stable switch is controllable to provide a low-impedance electric current flow path through the discharge resistor between the positive and negative conductors of the high-voltage bus in response to an activation signal from one of the first and second high-voltage DC contactor circuits.