A method for sensorless control of an electric motor implemented in a variable speed drive including: determining a control voltage to be applied to the motor; injecting a high frequency signal to the control voltage to obtain an excitation voltage, wherein one or more frequencies of the high frequency signal varies with time; applying the excitation voltage to the motor; measuring a current signal induced in the motor by the excitation voltage, wherein the current signal comprises a fundamental current, induced by the control voltage, and a disturbance current, induced by the high frequency signal; and demodulating the current signal.

Disclosed are various embodiments for a control system for motor/generator comprising: a controller configured to receive sensor input related to rotation of a plurality of coils relative to a throat of a partial toroidal magnetic cylinder, and energize the coils based on the sensor input.

A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.

Disclosed is a motor control apparatus, a motor control system, and a motor control method that estimate a stator resistance and a rotor position for sensorless control of a motor.

Disclosed is a motor control apparatus and a motor control method to estimate a stator resistance of a motor for sensorless control of the motor.

In sensorless control for a rotary machine, when variations in inductances for U, V, W phases due to manufacturing error are great, imbalance occurs among detected currents for the respective phases. Thus, estimation error of a magnetic pole position of a rotor increases, so that positioning accuracy is reduced. Correction filters for imparting gains in accordance with rotary machine constants for the respective phases are provided to control means or magnetic pole position calculation means, thereby correcting the imbalance occurring among the detected currents for the respective phases.

To provide a controller for rotary electric machine which can suppress the increase in the switching frequency by the voltage for estimation while reducing the estimation delay of the magnetic pole position (the rotational angle). A controller for rotary electric machine turns on and off switching devices which the inverter has and applies voltage to the winding, based on a comparison result between the voltage command and the carrier wave; generates the voltage command for estimation of a preliminarily set one period on a stationary coordinate system fixed to the winding; generates the carrier wave of the same one period as the one period of the voltage command for estimation; extracts the frequency component of the one period of the voltage command for estimation from the current detection value; and estimates a rotational angle based on the frequency component.

A method for identifying the magnetic anisotropy of an electric rotary field machine comprising a rotor and a stator is described, the method comprising the steps of setting injection pulses of equal absolute values during an injection interval, detecting a respective current response in form of current difference vectors, and determining the anisotropy from the voltage vectors and current difference vectors. Such a method should allow identifying of magnetic anisotropy in a simple way. To this end, injection pulses in the three-phase domain are used.

According to an aspect, there is provided an apparatus for performing angular position error estimation. The apparatus operates (601) a synchronous motor (111) according to a pre-defined pulsating torque signal using a sensorless vector control method with high-frequency voltage injection. The pre-defined pulsating torque signal has a zero mean and corresponds to a torque operating point. The apparatus measures (602) a first value of an estimated angular position at a first time instance corresponding substantially to an end point of the pre-defined pulsating torque signal and second values of the estimated angular position and an estimated angular speed at a second time instance occurring after the first time instance. Based on the measured values, the apparatus estimates (603) an error in the estimated angular position and stores (604) the error to a lookup table. After performing said steps for one or more pre-defined pulsating torque signals, the apparatus operates (607) the synchronous motor (111) using the lookup table for angular position error correction.

A pole direction detection device for detecting a pole direction of a synchronous motor having saliency comprises a high-frequency voltage application unit that applies a high-frequency voltage to the motor; an excitation phase change unit that changes an excitation phase of the motor to an arbitrary phase; a driving current detection unit that detects a driving current value of the motor; a pole direction estimation unit that detects a pole direction based on the excitation phase and the driving current value; a measurement unit that measures an inductance value of the motor; and a control unit that changes a frequency of the high-frequency voltage to be applied by the high-frequency voltage application unit based on the inductance value measured by the measurement unit.