A sensor unit includes a bus bar and a magneto-electric conversion device. The bus bar connects a plurality of switch elements constituting a part of a power conversion circuit and a motor. The magneto-electric conversion device is disposed to face a middle portion of the bus bar across a clearance in a predetermined direction to detect a magnetic field caused by an electric current flowing through the bus bar, to thereby detects the electric current. The bus bar includes a first end and a second end. The first end of the bus bar is connected to one of a switch terminal extending from the switch elements and a motor terminal extending from the motor, and the second end of the bus bas is connected to the other of the switch terminal and the motor terminal.

A method for operating a system having at least two mechanically coupled asynchronous motors, a computer program implementing the method and a system operating in accordance with the method are disclosed. One asynchronous motor is selected as master, with the other asynchronous motor(s) selected as slave(s). An effective (master) flux angle is measured in the motor selected as master and used as a basis for a setpoint value for controlling the flux angle of every other motor (slave) in the system. The flux angle of every slave motor is adjusted to the setpoint value as part of the control operation.

A textile machine includes a main driven system driven by a plurality of main motors, a plurality of slave driven systems each driven by at least one slave motor, and an energy supply/control arrangement for supplying energy to the main motors and the slave motors and for controlling the flow of energy between a power supply system and the main motors and the slave motors. The energy supply/control arrangement includes a first energy exchange unit, a first main motor unit, a second energy exchange unit, a second main motor unit, and a controller. The slave motors include at least one first slave motor connected to a first DC voltage bus system by an associated first slave motor unit and at least one second slave motor connected to a second DC voltage bus system by an associated second slave motor unit.

A textile machine includes a main driven system driven by a plurality of main motors, a plurality of slave driven systems each driven by at least one slave motor, and an energy supply/control arrangement for supplying energy to the main motors and the slave motors and for controlling the flow of energy between a power supply system and the main motors and the slave motors. The energy supply/control arrangement includes a first energy exchange unit, a first main motor unit, a second energy exchange unit, a second main motor unit, and a controller. The slave motors include at least one first slave motor connected to a first DC voltage bus system by an associated first slave motor unit and at least one second slave motor connected to a second DC voltage bus system by an associated second slave motor unit.

An electric motor system includes a drive shaft, a first electric motor, a second electric motor, a first inverter, a second inverter and a control unit. The drive shaft is rotatable around an axis. The first electric motor and the second electric motor rotate the drive shaft. The first inverter supplies power in order to generate a torque to the first electric motor. The second inverter supplies power in order to generate a torque to the second electric motor. The control unit controls the first inverter and the second inverter. The controller is configured to be able to change a ratio between an output torque of the first electric motor and an output torque of the second electric motor.

A vehicle driving device includes a case that accommodates therein a first rotary electric machine and a second rotary electric machine arranged with rotation axes thereof parallel to each other and radially adjacent to each other, and a power control device that controls electric power supplied to the first rotary electric machine and the second rotary electric machine. In the power control device, a control board, a power card and a cooler, a reactor and a capacitor, and a water jacket are disposed in order from top in a height direction.

A drive device includes a first motor, a second motor, and circuitry. The first motor includes a first rotation detector and is configured to rotate a driven shaft to apply a driving torque to the driven shaft. The second motor includes a second rotation detector and is configured to rotate the driven shaft to reduce backlash between the first motor and the driven shaft. The circuitry is configured to control the first motor and the second motor, based on a detection signal of the second rotation detector.

A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

There is provided herein an electrical motor and associated motor drive. The motor comprises an output shaft, and a speed sensor configured to measure the speed of the output shaft. The motor drive comprises a controller configured to output a current demand for the motor based on a speed error between a desired speed of the output shaft and the measured speed of the output shaft, and a feedback signal of the output current demand scaled by a first gain.