Semyon Royak

Rotor Position Estimation for Synchronous Machines Based on Equivalent EMF

This paper provides and analyzes a simple, robust, and universal model for rotor position estimation for synchronous machines. The rotor position is estimated using an equivalent electromotive force (EMF) model of a synchronous machine or, alternately, using a sliding-mode observer (SMO) based on the equivalent EMF model. The SMO provides fast convergence and low sensitivity to parameter variations. Experimental results with a 3.7-kW interior-permanent-magnet machine have validated the effectiveness of the proposed equivalent EMF scheme.

An on-line position error compensation method for sensorless IPM motor drives using high frequency injection

This paper addresses the position error issue existing in sensorless IPM motor drives using the high frequency injection (HFI) method. A simple-to-design on-line compensation method is proposed based upon filter group delay theory, which substantially minimizes the error between the estimated position and the actual position caused by filters in a conventional HFI system. The method determines the position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. Experimental results with a 10-hp interior permanent magnet motor are presented showing improved sensorless performance using the proposed method.

Implementation Issues in Voltage Zero Sequence-Based Encoderless Techniques

Recent articles demonstrate that sensorless drives for induction motors can operate at zero-electrical and mechanical frequencies with the aid of high-frequency signal injection techniques and processing the zero-sequence voltage signals. The paper presents some practical implementation issues affecting the performance of such a technique and shows how to improve the quality of the estimated angle. All the assessments are experimentally proved and have a general value that can be extended to other sensorless techniques injecting high-frequency signal.

Phase modulation-based technique for saliency position estimation of IPMSMs

The paper presents a new implementation technique able to extract the position of the saliencies in IPMSMs. The approach exploits the information contained in the phase modulation of the high frequency currents. Compared to other high frequency signal injection sensorless techniques, the proposed approach is easy to be implemented and suitable to be associated to unwanted multiple saliencies and their elimination techniques. Simulations and experimental results confirm the consistency of the proposed approach.

Generalized stability control for open loop operation of motor drives

This paper proposes a general approach to designing a stability control for open-loop operation that can be used for either induction motor, permanent magnet synchronous motor, or any other motor drives. A speed or frequency set point is adjusted by a frequency compensation value to provide the stability control to mitigate hunting or motor stoppage. The proposed method can be utilized in either conventional motor drives or motor drives with an output filter and a transformer used for oil pump applications.

Equivalent EMF based position observers for sensorless synchronous machines

This paper provides a simple, robust, and universal position observer for position sensorless control of synchronous machines. The observer is designed using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model. The sliding mode observer provides fast convergence and low sensitivity to parameter variations. Experimental results with a 5-hp Interior Permanent Magnet (IPM) machine have validated the effectiveness of the proposed equivalent EMF theory.

Design and implementation of position sensorless starting control in industrial drives with output filter and transformer for oil/pump applications

This paper proposes a position sensorless control scheme for an induction and permanent magnetic motor drive with output filter and transformer. The proposed method provides sufficient starting torque with controlled drive/motor current. In addition, transformer saturation is addressed. The sensorless starting scheme presented in this paper has been implemented in a commercial drive for deep well applications.

Generalized Stability Control for Open-Loop Operation of Motor Drives

This paper proposes a general approach to designing a stability control for open-loop operation that can be used for either induction motor, permanent magnet synchronous motor, or any other motor drives. A speed or frequency set point is adjusted by a frequency compensation value to provide the stability control to mitigate hunting or motor stoppage. The proposed method can be utilized in either conventional motor drives or motor drives with an output filter and a transformer used for oil pump applications.