A motor driving system includes motor driving circuitry configured to operate an electric motor. The system further includes a controller that is configured to send a signal to energize the electric motor and to measure a back electromotive force voltage of the electric motor. The controller is further configured to determine a temperature value based on the measured back electromotive force voltage using a back electromotive force voltage mapping that maps back electromotive force voltages to temperature values. The controller is further configured to determine an expected winding resistance value based on the determined temperature value using a resistance mapping that maps winding resistance values to temperature values. The controller is further configured to measure a winding resistance of the electric motor, to compare the measured winding resistance of the electric motor to the expected winding resistance value, and to output a match result indication based on the comparison.

A power tool with a direct current, DC, power source comprising a controller for controlling a driver circuit driving a brushless motor in a power tool, the driver circuit being coupled to a direct current, DC, power source and including a first switching element pair coupled to a first phase winding of the brushless motor and a second switching element pair coupled to a second phase winding of the brushless motor; and the controller being arranged to alternately switch a first switching element of the first switching element pair and a second switching element of the second switching element pair, wherein the first switching element and the second switching elements are coupled to a respective terminal of the DC power source. A power tool comprising such a controller, and a method of controlling a driver circuit driving a brushless motor in a power tool.

A motor control device according to an embodiment comprises a first signal generator, a second signal generator, a main controller, and a driver. The first signal generator is configured to generate, based on a clock signal indicating a stepping drive cycle of a motor, a first control signal. The second signal generator is configured to generate, based on a command phase indicating a target phase of a rotor of the motor, a second control signal. The main controller is configured to control the first signal generator and the second signal generator to output at least one of the first control signal and the second control signal. The driver is configured to drive the motor based on at least one of the first control signal and the second control signal.

A power supply system 1 includes: first power lines (21p, 21n) to which a first battery (B1) is connected; second power lines (31p, 31n) to which a second battery (B2) is connected; a voltage converter (5) which converts voltage; a power converter which converts electric power; a management ECU (71) and converter ECU (73) which operates the voltage converter (5); a smoothing capacitor connected to the first power lines (21p, 21n); and a motor ECU (72) which executes system interruption processing of determining the existence of failure of the contactors (22m, 22s, 32m, 32s) based on a change in voltage of the smoothing capacitor. The management ECU (71) and converter ECU (73) operate the voltage converter (5) so that a state in which the static voltage of the first battery (B1) is higher by at least the determination potential difference than the static voltage of the second battery (B2).

A system includes a starter generator configured to provide power to a first bus and a first inverter, a second inverter coupled to the first inverter, a first switch configured to selectively couple the second inverter to the first bus and to a second bus, a second switch configured to selectively couple a first motor to the first bus and to the second bus, and a controller. The controller sets the first switch to a second position and the second switch to a second position, causes the second inverter to convert the power from the first inverter to a starting power for starting the first motor, causes the second inverter to increase the starting power to match the power provided to the first bus from the starter generator, and switches the second switch to the first position, when the starting power matches the power from the starter generator.

An object of the present invention is to provide a power conversion device including a plurality of inverter circuits connected in parallel to a load, the power conversion device being capable of performing control with a smaller number of microcomputers, having high reliability, and being advantageous for miniaturization and cost reduction. Provided are: a plurality of inverter circuits connected in parallel to a load; a microcomputer which controls the plurality of inverter circuits; a plurality of signal selection units which select a drive signal of each of the plurality of inverter circuits; and a first transmission path and a second transmission path which are connected in parallel between the microcomputer and the plurality of signal selection units and transmit the drive signal of each of the plurality of inverter circuits from the microcomputer to each of the plurality of signal selection units. Each of the plurality of signal selection units selects any one of a first drive signal transmitted from the first transmission path and a second drive signal transmitted from the second transmission path.

An arrangement contains an asynchronous machine having a rotor and a stator. The arrangement is set up in a generator mode for feeding electrical energy into an AC voltage network. The arrangement is characterized in that the asynchronous machine can be doubly fed. The asynchronous machine can be connected in a matrix configuration to the AC voltage network by a modular multi-level converter, and the modular multi-level converter is set up in a motor mode of the arrangement for starting up the asynchronous machine while short-circuiting the rotor or the stator.

A propulsion system for an electric vehicle comprising a high voltage battery unit having a first high voltage battery connected in series with a second high voltage battery, which may also be referred to as a first and second battery bank, and one or more power inverters arranged to connect the battery banks to one or more electric machines. The one or more power inverters and the one or more electric machines are configured to form a first and a second three-phase system. The described architecture incorporating dual battery banks, and dual and/or multiphase inverters and electric machines can provide enhanced redundancy and limp home functionality in cases where a fault or error occurs in the inverter and/or in the electric machine so that a faulty three-phase system can be operated in a safe-state mode.

The drone according to the embodiment has a propeller, a first direct current motor, a power source, a second direct current motor, and a control unit. The first direct current motor drives the propellers. The power source supplies power to the first direct current motor. The second direct current motor has a rotating shaft that rotates in conjunction with the rotation of a rotating shaft of the first direct current motor. The control unit controls the first direct current motor. The second direct current motor charges the power source using the current output from the second direct current motor along with the rotation of a rotating shaft of the second direct current motor.

A power tool includes a motor and a power supply for supplying power to the motor. A driving circuit is connected to the motor. A voltage detection unit is used for detecting the voltage of the motor. A controller is configured to perform the following operations: if the motor voltage is greater than or equal to a preset voltage, the driving circuit will apply a voltage to the motor with a second slope, wherein the value range of the second slope is from 0 to 0.3. The disclosure also discloses a control method for starting under load of a power tool.