A power tool is provided including a power supply interface receiving a medium-voltage-rated removable battery pack having a maximum rated voltage in the range of 40 to 80 volts, and a brushless direct current (BLDC) motor. The motor includes a rotor and a stator having at least three stator windings corresponding to at least three phases of the motor, the rotor being moveable by the stator when the stator windings are appropriately energized within the corresponding phases. A multi-phase inverter bridge circuit is disposed between the power supply interface and the motor, and a controller is configured to output drive signals to the inverter bridge circuit to control flow of current from the battery pack to the motor such that the motor produces a maximum power output of at least approximately 1750 watts at a torque of approximately 1.5 to 2 Newton-meters.

A soft starter includes a plurality of live phases, wherein a semiconductor switching element and an electromechanical switch parallel-connected thereto are arranged in each phase. In the soft starter, on a load-facing side of the semiconductor switching elements and of the electromechanical switches, the plurality of phases are connected in a circuit forming a star point. The star point circuit includes at least one passive component and is configured for detecting a reduced voltage drop in a defective state of a semiconductor switching element and/or of an electromechanical switch.

A power tool is provided including a housing, a brushless motor disposed within the housing, a power switch circuit that supplies power from a power source to the brushless motor, and a controller configured to receive at least one signal associated with a phase current of the motor, detect an angular position of the rotor based on the phase current of the motor, and apply a drive signal to the power switch circuit to control a commutation of the motor based on the detected angular position of the rotor. If the supply of power to the motor is turned OFF to cause the motor to slow down and is turned back ON while the rotor speed exceeds a speed threshold, the controller electronically brakes the motor for a time interval to measure the phase current of the motor and detects the angular position of the rotor based on the measured phase current.

An inverter protection device is disclosed. An inverter protection device, which determines whether or not a pulse-width modulation (PWM) control signal provided to an inverter unit of an inverter is blocked in accordance with a voltage signal received from first and second switches of a safety relay which are parallelly connected, comprises: a first power switch which is switched to an on-state by means of a first voltage signal applied from the first switch; a second power switch which is switched to an on-state by means of a second voltage signal applied from the second switch; and a buffer unit which is on-off controlled in accordance with an output current of the first and second power switches and provides the PWM control signal to the inverter unit.

The present invention pertains to a heatsink arrangement for a power converter, wherein the heatsink is grounded via a grounding capacitor. The invention also pertains to a power converter for driving an electric motor, including a corresponding heatsink, semiconductor switches mounted on the heatsink and a fluid cooling system.

Provided is a motor drive device comprising a motor control unit that controls a plurality of upper arm-side switching elements and a plurality of lower arm-side switching elements provided to an inverter for driving a motor; a current determination unit that determines whether a motor current flowing through at least one switching element of the plurality of upper arm-side switching elements and the plurality of lower arm-side switching elements is equal to or smaller than a threshold value; and a short-circuit control unit that performs switching between all-on of the plurality of upper arm-side switching elements and all-on of the plurality of lower arm-side switching elements, on condition that the motor current is equal to or smaller than the threshold value, in a short-circuiting operation of alternately switching all-on of the plurality of upper arm-side switching elements and all-on of the plurality of lower arm-side switching elements.

An electrical machine includes a with a parallel first and second phase windings. A first neutral bus is connected to the first phase winding and a second neutral bus is connected to the second phase winding. A first voltage sensor is coupled to the first neutral bus and a second voltage sensor coupled to the second phase winding for monitoring current imbalance between the first and second phase windings.

An energy conversion apparatus includes: a first switch module, a motor inverter having a first bus terminal connected with a first end of a battery and a second bus terminal connected with a second end of the battery through the first switch module, a motor winding having a first end connected with a midpoint end of the motor inverter, and a second switch module and a first capacitor connected in series. A first end of the serial-connected second switch module and the first capacitor is connected with a second end of the motor winding. A second end of the serial-connected second switch module and the first capacitor is connected with the second bus terminal.

An electrified vehicle includes a traction battery, an inverter coupled to the traction battery and operable to convert direct current (DC) power from the traction battery to three-phase alternating current (AC) power, a three-phase electric machine coupled to the inverter by associated cables, a sensor configured to generate a signal associated with rotational position of a rotor of the three-phase electric machine, a current sensor associated with each cable/phase of the three-phase electric machine, and a controller programmed to generate non-zero phase current at each of a plurality of predetermined regularly spaced rotational positions by either adjusting rotor angle or injecting q-axis current, command the inverter to inject a test current pulse to the electric machine, and generate a diagnostic signal in response to any one of the current sensor signals being less than an associated threshold to detect a cable or current sensor anomaly in a single phase.

An inverter device of an electric drive device may be configured to convert a direct voltage of an intermediate circuit of the electric drive device into a multi-phase alternating current to operate an electric motor of the electric drive device. A safety signal may be received by a control unit of the electric drive device, which instructs the control unit to operate the electric motor in a safe operating mode and to discharge the intermediate circuit at same time. If an active short circuit mode is preset, the inverter device is controlled to operate the electric motor in the active short circuit mode and to discharge the intermediate circuit in the discharge mode. If a freewheel mode is preset, the inverter device is controlled to operate the electric motor in the freewheel mode and, upon satisfaction of a current criterion, controlled to discharge the intermediate circuit in the discharge mode.