A motor and a control method for making the generating and regeneration efficiency higher than before are provided. A motor including a rotor, a storage battery and a capacitor (a source) is provided to charge a produced electrical energy, a SR motor portion rotates the rotor by magnetic force produced with a current supplied by the source and generates by converting rotational energy of the rotor into electrical energy, current sensors measure the currents supplied to excitation coils, and a semiconductor switching control circuit for driving and generation to maintain the rotation by increasing the current with supply of electrical energy from the source to the excitation coils if the currents measured by the current sensors fall below a predetermined lower limit for making the rotor rotate due to the charging.

A device for processing a workpiece includes at least one plunger pump, which is drivable by means an electric motor and which generates a highly pressurized volume flow, which volume flow can be interrupted in controlled fashion and emerges from at least one connected consumer. The volume flow is conveyed at substantially constant high pressure via a pressure line to the consumer. The electric motor is a reluctance motor, which is controllable by a connected frequency converter. A pressure sensor is connected to the pressure line, which pressure sensor is connected to a controller.

In a control device for a switched reluctance motor, a voltage drop control is executed in which a voltage dropped to be lower than a voltage applied in a case where the switched reluctance motor is driven in a high-load region is applied to the switched reluctance motor, in a case where the switched reluctance motor is driven in a low-load region. The low-load region is a lower load region than the high-load region.

To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced. A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is T.sub.c1 K, and the Curie temperature of another is T.sub.c2 K, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at T.sub.s K that is (T.sub.c1100) K or higher and lower than T.sub.c2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature T.sub.s K or T.sub.c1 K, whichever is lower.

To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced.

A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is T.sub.c1 K, and the Curie temperature of another is T.sub.c2 K, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at T.sub.s K that is (T.sub.c1100) K or higher and lower than T.sub.c2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature T.sub.s K or T.sub.c1 K, whichever is lower.

A motor and control method for making the generating and regeneration efficiency higher than before are provided. A motor including a rotor, a storage battery and a capacitor (a source) is provided to charge a produced electrical energy, a SR motor portion rotates the rotor by magnetic force produced with a current supplied by the source and generates by converting rotational energy of the rotor into electrical energy, current sensors measure the currents supplied to excitation coils, and a semiconductor switching control circuit for driving and generation to maintain the rotation by increasing the current with supply of electrical energy from the source to the excitation coils if the currents measured by the current sensors fall below a predetermined lower limit for making the rotor rotate due to the charging.

In a control device for a switched reluctance motor, a voltage drop control is executed in which a voltage dropped to be lower than a voltage applied in a case where the switched reluctance motor is driven in a high-load region is applied to the switched reluctance motor, in a case where the switched reluctance motor is driven in a low-load region. The low-load region is a lower load region than the high-load region.