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.

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.

Provided is a motor system adapted for modern society, which does not use a rare-earth magnet, improves a torque weight ratio by approximately one digit in comparison with the conventional motor, and has transfer efficiency of 90% between electric energy and rotational energy. A stator (1) has a dual-ring tooth-groove iron core, which has magnetic pole surface on both side surfaces and receives coils of basically two-phase structure divided to be multiplexed, with divided coils being interconnected. A rotor (2) is formed to be capable of rotating while holding eight sets of attraction poles having magnetic pole surfaces on both ends, with each set of attraction poles forming four air-gap-facing surfaces by positioning the dual-ring tooth-groove iron core between the attraction poles so that both side surfaces of the dual-ring tooth-groove iron core face the attraction poles via an air gap (6). Magnetic energy accompanying coil switching can be reduced to one part per dozens through the dual effect of reduction owing to coil division and dispersion owing to interconnection. The torque weight ratio can be improved approximately by one digit through synergistic effect of torque increase owing to integration of magnetomotive forces by interconnection, torque increase owing to composite structure of the attraction poles, and weight reduction of the iron core.

Provided is a motor system adapted for modern society, which does not use a rare-earth magnet, improves a torque weight ratio by approximately one digit in comparison with the conventional motor, and has transfer efficiency of 90% between electric energy and rotational energy. A stator (1) has a dual-ring tooth-groove iron core, which has magnetic pole surface on both side surfaces and receives coils of basically two-phase structure divided to be multiplexed, with divided coils being interconnected. A rotor (2) is formed to be capable of rotating while holding eight sets of attraction poles having magnetic pole surfaces on both ends, with each set of attraction poles forming four air-gap-facing surfaces by positioning the dual-ring tooth-groove iron core between the attraction poles so that both side surfaces of the dual-ring tooth-groove iron core face the attraction poles via an air gap (6). Magnetic energy accompanying coil switching can be reduced to one part per dozens through the dual effect of reduction owing to coil division and dispersion owing to interconnection. The torque weight ratio can be improved approximately by one digit through synergistic effect of torque increase owing to integration of magnetomotive forces by interconnection, torque increase owing to composite structure of the attraction poles, and weight reduction of the iron core.

A linear electromotive machine, for example a motor, generator and/or eddy-current brake is disclosed. The machine comprises a stator and a rotor, the rotor comprising a Halbach magnet array mounted on a fibre-reinforced polymer rotor frame. Also disclosed is a transportation system including such a machine and a method of manufacturing such a machine.

A linear electromotive machine, for example a motor, generator and/or eddy-current brake is disclosed. The machine comprises a stator and a rotor, the rotor comprising a Halbach magnet array mounted on a fibre-reinforced polymer rotor frame. Also disclosed is a transportation system including such a machine and a method of manufacturing such a machine.

An electric drive system includes an energy storage system (ESS), a power conversion system, and an alternating current (AC) traction system. The ESS provides or receives electric power. The ESS includes a first energy storage unit and a second energy storage unit. The power conversion system is electrically coupled to the ESS for converting an input power to an output power. The AC traction system is electrically coupled to the power conversion system for converting the output power of the power conversion system to mechanical torques. The AC traction system includes a first AC drive device and a second AC drive device. An energy management system (EMS) is in electrical communication with the ESS, the AC traction system, and the power conversion system for providing control signals.

An electric drive system includes an energy storage system (ESS), a power conversion system, and an alternating current (AC) traction system. The ESS provides or receives electric power. The ESS includes a first energy storage unit and a second energy storage unit. The power conversion system is electrically coupled to the ESS for converting an input power to an output power. The AC traction system is electrically coupled to the power conversion system for converting the output power of the power conversion system to mechanical torques. The AC traction system includes a first AC drive device and a second AC drive device. An energy management system (EMS) is in electrical communication with the ESS, the AC traction system, and the power conversion system for providing control signals.