A drive control device includes: a driver including a circuit and configured to drive a motor; and a controller configured to control the driver. The controller is configured to: in a period other than a stop period during driving of the motor, control the driver by a PWM control of a synchronous rectification type, the stop period lasting for a specified time or longer during the driving of the motor; and in the stop period during the driving of the motor, suspend the PWM control of the synchronous rectification type and control the driver such that the motor is set to a short-circuit brake state or a disconnected state.

A method of setting up an electrical motor speed control in a fluidic system including a turbomachine, an electric motor having a number p of pole pairs rotating the turbomachine, a variable speed drive controlling the speed of the electric motor, a sensor measuring a parameter H, Q of the turbomachine, and a system controller receiving the sensor's measurements and controlling the operation of the fluidic system. The method includes driving the electric motor at a predetermined electrical frequency, Fe, such that the turbomachine rotates with a controlled rotational speed N, determining the point of intersection of the system curve of the fluidic system and of the performance curve of the turbomachine to obtain the turbomachine's nominal operating point, and thus the nominal value, Hn, Qn, of the turbomachine parameter, measuring, with the sensor, the current value, H, Q of the turbomachine parameter, calculating the controlled rotational speed N by inputting, into the Affinity Laws, the determined nominal value, Hn, Qn, the measured current value, H, Q, and the known nominal rotational speed, Nn, of the turbomachine, determining the number p of pole pairs of the electric motor based on the ratio of the electrical frequency Fe and the calculated controlled rotational speed N, and adapting the setup of the variable speed drive to match the determined number p of pole pairs.

A method is described for controlling an electric motor having a rotor. The method is carried out after a shutdown of the motor has been initiated. The method includes starting a timer in a motor controller, performing regenerative braking to recapture kinetic energy from the rotor as electrical energy, and using the recaptured electrical energy from the regenerative braking to power the motor controller. If the timer in the motor controller exceeds a predetermined timer value, a flag is set in memory in the motor controller to indicate that the motor has stopped.

A method is described for controlling an electric motor having a rotor. The method is carried out after a shutdown of the motor has been initiated. The method includes starting a timer in a motor controller, performing regenerative braking to recapture kinetic energy from the rotor as electrical energy, and using the recaptured electrical energy from the regenerative braking to power the motor controller. If the timer in the motor controller exceeds a predetermined timer value, a flag is set in memory in the motor controller to indicate that the motor has stopped.

A method includes monitoring electrical output in an open control loop from a variable speed drive to a remote permanent magnet motor, the variable speed drive electrically connected to the permanent magnet motor via a power transmission line. The method includes, in response to detecting a variation in the electrical output at the variable speed drive, synchronizing a frequency of a rotor shaft of the permanent magnet motor with a constant electromagnetic field frequency of a stator of the permanent magnet motor for a predetermined period of time. After the predetermined period of time, the method includes increasing the electromagnetic field frequency of the stator to an operational frequency threshold to accelerate the frequency of the rotor shaft of the permanent magnet motor. In response to reaching the operational frequency threshold, the method includes determining an internal position of the rotor based on the variable electromagnetic field frequency.

A rotary electric machine control device for controlling driving of a rotary electric machine including a plurality of winding sets, includes: a plurality of drive circuits; and a plurality of control units, each of which includes: an individual current limit value calculation unit; a current limit value calculation unit; and a control signal calculation unit. The current limit value calculation unit switches between a current limit value sharing mode and a current limit value non-sharing mode. An electric power steering device includes: the rotary electric machine control device; the rotary electric machine that outputs an assist torque for assisting a steering operation of a steering wheel by a driver; and a power transmission unit that transmits a driving force of the rotary electric machine to a drive target.

A drive control device include a processor and a memory including instructions that, when executed by the processor, cause the processor to perform operations. The operations include: comparing a rotation speed of a motor driven by a PWM control of a synchronous rectification type and a target value of the rotation speed and calculating an error speed; calculating a torque required in the motor based on the calculated error speed; calculating a drive voltage of the motor in the synchronous rectification type based on the calculated torque, the rotation speed of the motor, and an electrical specification of the motor; and setting a duty ratio of a PWM signal in the synchronous rectification type based on the calculated drive voltage.

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.

A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.