The present invention relates to a 4-phase switched reluctance motor which is configured as a 4-phase motor by coaxially arranging two 2-phase motor units, is capable of effectively driving forward and backward by calculating a switching angle at a time point earlier than the starting point of an inductance increasing period in forward and backward rotations, maximizes the initial driving torque, and minimizes vibration noise by not generating the biased force on a shaft.

The invention relates to a method for operating an electric machine (2). The electric machine (2) is driven using field-oriented regulation, and a current relative position (i) of a rotating field is detected by means of at least one sensor (5). At least one electric voltage (Us, Us) is generated which causes an electric rotor flux corresponding to the position (i) detected by the sensor, the electric machine (2) is monitored for a torque generated by the voltage (Us, Us) and an absolute position of the rotating field is determined depending on the generated torque.

A motor control apparatus which is applied to an actuator provided with a motor and an encoder, and drives the motor is provided. The motor control apparatus comprises: a controller that learns an initial position of a rotor, and also decides an energized phase; and a drive circuit that performs switching operation to energize an energized phase. The controller learns that, in learning the initial position, the initial position of the rotor is a two-phase facing position in which two adjacent salient poles of the rotor face salient poles of two energized phases of a stator, and the initial position of the rotor is a one-phase facing position in which one salient pole of the rotor faces a salient pole of one non-energized phase of the stator.

The invention relates to a method for operating an electric machine (2). The electric machine (2) is driven using field-oriented regulation, and a current relative position (i) of a rotating field is detected by means of at least one sensor (5). At least one electric voltage (Us, Us) is generated which causes an electric rotor flux corresponding to the position (i) detected by the sensor, the electric machine (2) is monitored for a torque generated by the voltage (Us, Us) and an absolute position of the rotating field is determined depending on the generated torque.

A motor control apparatus which is applied to an actuator provided with a motor and an encoder, and drives the motor is provided. The motor control apparatus comprises: a controller that learns an initial position of a rotor, and also decides an energized phase; and a drive circuit that performs switching operation to energize an energized phase. The controller learns that, in learning the initial position, the initial position of the rotor is a two-phase facing position in which two adjacent salient poles of the rotor face salient poles of two energized phases of a stator, and the initial position of the rotor is a one-phase facing position in which one salient pole of the rotor faces a salient pole of one non-energized phase of the stator.

A controller for a switched reluctance machine is operated to close a switch which would otherwise be open so as to connect a phase winding to the DC link to which the winding is connected during other parts of the electrical cycle. This produces a condition which allows the insulation of the system to be monitored by applying a voltage between the DC link and ground.

Electric machines may be attained by a variety of systems, processes, and techniques. In particular implementations, an electric machine may include a stator core composed of a variety of circumferential segments and a rotor core. In certain implementations, the stator core may include a number of individually-formed poles, each including a radially extending portion and a base portion. The base portions may be coupled together to form the stator core, and the radially extending portions may defined an inner cavity. The rotor core may include a number of radially extending poles, with the rotor sized to rotate inside the inner cavity of the stator.

An example converter for a switched reluctance (SR) generator includes one or more gate driver circuits that are not only used to synchronously control switches, such as insulated gate bipolar transistors (IGBTs) of the converter, but also used to provide priming function during start-up of the generator. Since, an SR generator does not have to ability to self provide magnetic flux, priming current is provided to coils of the SR generator to initiate a magnetic flux. By using the gate drive circuit to provide the priming current, an additional priming circuit is not required. As a result, the converter design is more streamlined, with reduced complexity, cost, and size. When a bus voltage of the converter is below a threshold level, the one or more gate drive circuits can provide the priming current on the bus to initiate the SR generator.

A controller for a switched reluctance machine is operated to close a switch which would otherwise be open so as to connect a phase winding to the DC link to which the winding is connected during other parts of the electrical cycle. This produces a condition which allows the insulation of the system to be monitored by applying a voltage between the DC link and ground.