Abstract: In one aspect, a system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine.

Abstract: A pair of direct d-q-axis voltage commands is associated with a monotonically varying test sequence of test rotor angular positions to determine a correct rotational direction of a rotor of the motor in response to application of the pair of direct d-q-axis voltage commands to the motor. The rotor of the motor rotates (e.g., self spins in a diagnostic mode) in response to the applied direct d-q-axis voltage commands and applied monotonically varying test sequence of test rotor angular positions. The primary positioning module or data processor determines that conductor connections between the inverter (e.g., motor controller) and the motor are correct if the calculated shaft speed sign is positive with respect to an applied monotonically varying test sequence of rotor angular positions that monotonically increases.

Abstract: Disclosed is an assembly encompassing a three-phase machine and a frequency converter. Said assembly has the following characteristics: the three-phase machine comprises a stator and a rotor; at least the three circuits of the stator and/or the rotor can be operated in an insulated manner relative to each other for the three phases of the rotary current while being connectable to one separate terminal point of the frequency converter, respectively, so as to be insulated relative to each other; and the frequency converter is embodied with a D.C. link having a grounded neutral in such a way that a voltage or current which is symmetric regarding the potential to ground can be output at any moment between the two associated terminal points of each circuit.

Abstract: A system for controlling a trapezoidally (square wave) driven DC motor includes a unipolar commutation circuit coupled between a DC power supply and a brushless DC motor. The motor has three phases formed by respective stator windings coupled at respective proximal ends to a common node and having respective opposite ends remote from the common node. The commutation circuit drives the motor according to a commutation cycle including three primary steps. During each primary step, one of the phases is driven while the other two phases are not driven. Voltages at the remote ends of the undriven phases are sensed, and timing signals are generated at points where the voltages coincide. The timing signals are used to determine motor position and speed, and to synchronize the commutation cycle with motor position and speed. In one embodiment, the commutation cycle includes transitional steps between the primary steps for smoother operation.

Abstract: A field weakening vector controller is disclosed which calculates a d-axis current command value for a power converter to drive a permanent magnet synchronous motor. The field weakening vector controller includes a stabilization calculator, a d-axis current command calculator, a q-axis current command calculator, and a phase calculator. The d-axis current command calculator corrects the d-axis current command value, while the stabilization calculator calculates a product of the phase error and the d-axis command value. The q-axis current command calculator corrects the q-axis current command value using this product.

Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.

Abstract: In a synchronous motor control device that corrects a deviation in rotational position which is related to a rotational position detector for a synchronous motor on which vector-control is performed, the synchronous motor control device includes: a current instruction generator that disables a torque instruction to set d-axis and q-axis current instructions as zero when a phase correction instruction is inputted; a current controller that outputs d-axis and q-axis voltage instructions based on the d-axis and q-axis current instructions; a phase correction quantity detector for determining the amount of offset in which the d-axis voltage instruction becomes zero when the phase correction instruction is inputted and the d-axis voltage instruction is not zero; an adder for adding a rotor positional angle and the amount of offset; and a voltage converter for determining three-phase voltage instructions based on the additional value, the d-axis and q-axis voltage instructions.

Abstract: A motor control apparatus comprises a fundamental current control device that controls a fundamental current in a 3-phase AC motor in an orthogonal coordinate system constituted of a d-axis and a q-axis rotating in synchronization with the rotation of the 3-phase AC motor, a higher harmonic current control device that controls a higher harmonic current in the motor in an orthogonal coordinate system constituted of a dh-axis and a qh-axis rotating at a frequency that is an integral multiple of the frequency of the fundamental component of the current flowing to the motor, an estimating device that estimates the level of the harmonic speed electromotive force in the motor in the dhqh-axis coordinate system and a compensating device that compensates the harmonic speed electromotive force estimated by the estimating device.

Abstract: A method of controlling a synchronous motor comprises the steps of: preparing a rotor of magnetic anisotropy and a stator having a coil used in common for a field coil and an armature coil; and controlling absolute value and phase of coil current supplied to the common coil on the basis of a resultant vector of a current vector for generating a field and an armature current vector. The control method can be realized by a sample control apparatus incorporated in the synchronous motor.

Abstract: A disc record/reproduce apparatus with a brushless dc motor having no separate dedicated position sensor, controls rotation of the dc synchronous motor by back-electromotive force signals developed in windings of the brushless dc motor using a/d converter included in one-chip microprocessor in the first mode, and controls by position and index signals recorded on the disc in the second mode. During start-up, a start-up oscillator is used. The control with a back-electromotive force signal is provided to enable the microprocessor to write a position signal on a disc and provided for inspecting the brushless dc motor independently. In the second mode, functions for executing the back-electromotive force control in the microprocessor is disabled during recording and reproducing of data to prevent overload on the microprocessor which is busy because of communication with an external computer and control of head position.

Abstract: A synchronous motor comprising a permanent-magnet rotor and a stator which, at startup, uses rectifiers for supplying the stator coil with rectified current and a commutator consisting of sliders and brushes both rotary in union with the rotor in order to supply only the rectified component, effective to energize the rotor's rotation, from the AC power-supply, and which is provided with a mechanical conversion device designed such that, when the rotor's rotation has reached nearly the speed of synchronous rotation, the slider is allowed to move in the direction along the rotary shaft to become released from contact with the brush, for removal of contact load and at the same time to supply the stator directly with the power-supply AC.