Peyman Niazi

A Low-Cost and Efficient Permanent-Magnet-Assisted Synchronous Reluctance Motor Drive

In this paper, various key points in the rotor design of a low cost permanent magnet assisted synchronous reluctance motor (PMa-SynRM) are introduced and their effects are studied. Finite element approach has been utilized to show the effects of these parameters on the developed average electromagnetic torque and total d-q inductances. One of the features considered in the design of this motor is the magnetization of the permanent magnets mounted in the rotor core using the stator windings. This feature will cause a reduction in cost and ease of manufacturing. Effectiveness of the design procedure is validated by presenting simulation and experimental results of a 1.5 kW prototype PMa-SynRM

Robust Maximum Torque per Ampere (MTPA) Control of PM-Assisted SynRM for Traction Applications

Recently, permanent-magnet-assisted (PMa) synchronous reluctance motors (SynRMs) have been introduced as a possible traction motor in hybrid electric vehicle applications. In order to achieve maximum torque per ampere (MTPA), knowledge of the motor parameters is necessary. Due to the high ambient temperature inside the engine cavity as well as the saturation effect, variation of motor parameters such as inductances and permanent magnet (PM) flux density is not avoidable. Offline models for estimating the motor parameters are known as a computationally intensive method, particularly, when the effect of cross saturation and PM flux deterioration are included. In this paper, a practical MTPA control scheme, along with a simple parameter estimator for the PMa SynRM, is introduced. This method is capable of maintaining the MTPA condition and stays robust against motor parameter variations. To verify the validity and feasibility of the proposed controller, several simulations and experiments results on a low-power laboratory prototype PMa SynRM have been presented.

A sensorless integrated doubly-fed electric alternator/active filter (IDEA) for variable speed wind energy system

In response to energy concerns and power quality issues, a viable, simple and low cost sensorless integrated doubly-fed electric alternator/active filter (IDEA) for variable wind energy conversion system (WECS) is proposed. The proposed IDEA is capable of simultaneous generation of optimized green power and improving power quality, which are achieved by canceling the most significant and troublesome harmonics of the utility lines. Power factor correction and reactive power control are the other two significant features of the proposed technology. A sensorless field oriented method to control the IDEA with higher power density is also part of this development. Analysis and simulation as well as experimental results are presented to demonstrate the effectiveness of the proposed IDEA. The overall algorithm has been implemented using the TI DSP controller, TMS320LF2407.

Online Parameter Estimation of Permanent-Magnet Assisted Synchronous Reluctance Motor

In comparison with the conventional synchronous reluctance machines, permanent-magnet assisted synchronous reluctance motor drives (PMa-SynRMs) have offered better torque capabilities and power factors. In order to achieve maximum efficiency, knowledge of the motor parameters is necessary to implement advanced control algorithms. Variation of motor parameters due to temperature and airgap flux has been reported in literature. Using offline models to estimate the motor parameters is known as a computationally intensive method, especially when the effect of cross saturation is included in the models. Therefore, in practical applications, online parameter estimation is favored to achieve a high-performance control system. In this paper, a simple practical method for parameter estimation of PMa-SynRM is introduced. This method is capable of identifying d- and q-axes inductances and the permanent-magnet back electromotive force

A low-cost and efficient permanent magnet assisted synchronous reluctance motor drive

In this paper, various key points in the rotor design of a low cost permanent magnet assisted synchronous reluctance motor (PMa-SynRM) are introduced and their effects are studied. Finite element approach has been utilized to show the effects of these parameters on the developed average electromagnetic torque and total d-q inductances. One of the features considered in the design of this motor is the magnetization of the permanent magnets mounted in the rotor core using the stator windings. This feature will cause a reduction in cost and ease of manufacturing. Effectiveness of the design procedure is validated by presenting simulation and experimental results of a 1.5 kW prototype PMa-SynRM

Robust maximum torque per amp (MTPA) control of PM-assisted SynRM for tractions applications

Recently, permanent magnet assisted (PMa)-synchronous reluctance motors (SynRM) have been introduced as a possible tractions motors in hybrid electric vehicle applications. In order to achieve maximum torque per ampere (MTPA), knowledge of the motor parameters is necessary. Due to the high ambient temperature inside the engine cavity and also saturation effect, variation of the motor parameters such as inductances and permanent magnets flux density is not avoidable. Off-line models for estimating the motor parameters are known as a computationally intensive method, especially when the effect of cross saturation and permanent magnet flux deterioration are included. In this paper, a practical maximum torque per ampere control scheme along with a simple parameter estimator for PMa-SynRM is introduced. This method is capable of maintaining the MTPA condition and stays robust against the motor parameters variations. To verify the validity and feasibility of the proposed controller, several simulations and experiments results on a low power laboratory prototype PMa-SynRM have been presented.

Design of Permanent Magnet-Assisted Synchronous Reluctance Motors Made Easy

Electric motor design is a multi-variable problem which involves geometric dimensions of the stator and rotor. Presenting a unique solution for a family of optimization criteria has always been a challenge for motor designers. Several numerical tools such as finite element methods (FEM) have been developed to perform a precise analysis and predict the outcome of the design. However, limits in parametric analysis as well as mathematical and computational burden on numerical tools usually prohibit the designer in obtaining a unique solution for the design problem. These limits and demands in optimized solutions motivate the designer to use analytical models in order to perform a comprehensive parametric design. An accurate analytical model is crucial for this purpose. In this paper, an analytical model for permanent magnet assisted synchronous reluctance motor (PMa- SynRM) with four flux barriers and one cutout per pole is developed. Flux densities are found in the air gap, in the cutouts, and in the flux barriers; thus, the back-EMF developed by the permanent magnets is derived. Equations for the d-axis and the q-axis inductances are also obtained. Electromagnetic torque is finally derived using the co-energy method. The developed analytical model highlights the contribution of the reluctance variation and permanent magnets on the developed torque. Simulation results are obtained using both Matlab and Ansoft/Maxwell packages. These outcomes are supported by the experimental results obtained from a laboratory test bed.

On-line parameter estimation of permanent magnet assisted synchronous reluctance motor drives

In comparison with the conventional synchronous reluctance machines, permanent magnet assisted synchronous reluctance motor drives (PMa-SynRM) have offered better torque capabilities and power factors. In order to achieve maximum efficiency knowledge of the motor parameters is necessary to implement advanced control algorithms. Variation of motor parameters due to temperature and airgap flux has been reported in the literatures. Using off-line models for estimating the motor parameters is known as a computationally intensive method, especially when the effect of cross saturation is included in the models. Therefore in practical applications, on-line parameter estimation is favored to achieve a high performance control system. In this paper, a simple practical method for parameter estimation of PMa-SynRM is introduced. This method is capable of identifying the d- and q-axes inductances and the permanent magnet back-EMF

Design of a low-cost concentric winding permanent magnet assisted synchronous reluctance motor drive

In this paper, various key points in the rotor design of a low cost permanent magnet assisted synchronous reluctance motor (PMa-SynRM) are introduced and their effects are studied. Finite element approach has been utilized to show the effects of these parameters on the developed average electromagnetic torque and total d-q inductances. Effect of concentric winding on overall efficiency and design criteria is investigated. Effectiveness of the design procedure is validated by presenting simulation results.

An analytical model for an N-flux barrier per pole permanent magnet-assisted synchronous reluctance motor

In this paper, a general analytical model for permanent magnet assisted synchronous reluctance machine with ‘N’ barrier, including space harmonics using winding function is being developed. Flux densities in the air gap, in the cutouts, and in the flux barriers are found. Back-EMF developed by the permanent magnets using winding function is derived. Equations for the d-axis and the q-axis inductances are also obtained. Electromagnetic torque is finally derived using the co-energy method. The developed analytical model results are supported by finite element analysis (FEA). Once the model is verified, then it is much faster to make changes to the geometrical dimensions and determine their effects on the torque, inductances, etc than FEA . The developed analytical model highlights the contributions of the reluctance variations and permanent magnets on the developed torque. An interactive software has been written in Matlab environment for ‘N’ flux barrier. Simulation results are obtained in the Ansoft/Maxwell environment for four flux barriers per pole. These results are supported by the experimental results obtained from a laboratory test bed.