Position-sensorless control of permanent-magnet-assisted synchronous reluctance motor

The sensorless control of permanent-magnet-assisted synchronous reluctance (PMASR) motors is investigated, in order to conjugate the advantages of the sensorless control with full exploitation of the allowed operating area, for a given inverter. An additional pulsating flux is injected in the d-axis direction at low and zero speed, while it is dropped out, at large speed, to save voltage and additional loss. A flux-observer-based control scheme is used, which includes an accurate knowledge of the motor magnetic behavior. This leads, in general, to good robustness against load variations, by counteracting the magnetic cross saturation effect. Moreover, it allows an easy and effective correspondence between the wanted torque and flux and the set values of the chosen control variables, that is d-axis flux and q-axis current. Experimental verification of the proposed method is given, both steady-state and dynamic performance are outlined. A prototype PMASR motor will be used to this aim, as part of a purposely assembled prototype drive, for light traction application (electric scooter

Cross-Saturation Effects in IPM Motors and Related Impact on Sensorless Control

Permanent-magnet-assisted synchronous reluctance motors are well suited to zero-speed sensorless control because of their inherently salient behavior. However, the cross-saturation effect can lead to large errors on the position estimate, which is based on the differential anisotropy. These errors are quantified in this paper as a function of the working point. The errors that are calculated are then found to be in good accordance with the purposely obtained experimental measurement

Development of a Permanent Magnet Assisted Synchronous Reluctance motor

This thesis is a development research project for a permanent magnet assisted synchronous reluctance motor (PMaSynRM) used with frequency converter (FC). The motor size is specified to International Electrotechnical Commission (IEC) with frame size 250. The objective of this thesis is to develop air-cooled high dynamic performance (HDP) series motor with PMaSynRM rotor technology. The PMaSynRM designing goals are good thermal behavior and high efficiency at wide speed range with a wide field weakening area. To study the objectives of this thesis a prototype of PMaSynRM is designed and manufactured. The designed prototype of PMaSynRM is investigated with simulations and measurements at different operating points on a load type of constant torque and constant power with wide field weakening area. The performance values of PMaSynRM prototype rotor is compared with simulations and measurements to an induction motor’s (IM’s) rotor which is earlier manufactured and measured in the same HDP 250 stator. The simulation and measurement results showed that PMaSynRM has benefits on thermal behavior and efficiency compared to IM. PMaSynRM measured operating points at constant torque from running speed 525 rpm to 1050 rpm and at constant power from 1050 rpm to 3000 rpm showed that PMaSynRM is well suitable to operate in wide speed range because of wide field weakening area. PMaSynRM simulation and measurement results had a bit difference on the efficiencies because the Adept FCSmek simulation tool does not take into account the high level of supply harmonics outside field weakening area which are produced from frequency converter. The prototype of PMaSynRM reached to higher output level than the IM because of good thermal behavior. The PMaSynRM also met the expectations on high efficiency on a wide field weakening area.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Fast synthesis of permanent magnet assisted synchronous reluctance motors

open3This paper describes a procedure for a practical synthesis of both a synchronous reluctance motor and a permanent magnet assisted synchronous reluctance motor. The procedure is completely analytical, yielding a rapid drawing of the motor geometry, taking into account both magnetic and mechanical considerations. From the application requirements, the external volume of the motor is computed. The further practical needs, such as maximum outer space, maximum available length, existing stator lamination, and so on are considered. Then, the design of the rotor geometry is carried out. The PM size is determined considering the demagnetisation limit according to the maximum current loading.openBianchi, Nicola; Mahmoud, Hanafy; Bolognani, SilverioBianchi, Nicola; Mahmoud, Hanafy; Bolognani, Silveri

Maximum Torque per Ampere Control of Permanent Magnet Assisted Synchronous Reluctance Motor: An Experimental Study

In recent times, permanent magnet assisted synchronous reluctance motors (PMaSRM) have been considered as suitable traction motors for electric vehicle applications. In this type of machine, where the share of reluctance torque is more significant than the excitation torque, it is more appropriate to use a control strategy that can fully utilize the reluctance torque. This paper deals with a new structure of permanent magnet-assisted synchronous reluctance motors that was designed and manufactured in a previous study. This paper suggests applying, in a first study, a constant parameter maximum torque per ampere (MTPA) strategy to make a contribution towards the control of such structure that is becoming increasingly attractive in the field of electric transportation. This method is usually used to control interior permanent magnet synchronous motors to minimize the copper losses of the system. Before implementing and simulating this method, the mathematical models of the suggested motor and the inverter are given. An experimental study is conducted on a small-scale 1 kW prototype PMaSRM using a MicrolabBox Dspace to test and examine the proposed control. Simulation and experimental results are presented in this article in order to verify the validity of the developed control strategy

Permanent Magnet-Assisted Omnidirectional Ball Drive

We present an omnidirectional ball wheel drive design that utilizes a permanent magnet as the drive roller to generate the contact force. Particularly interesting for novel human-mobile robot interaction scenarios where the users are expected to physically interact with many palm-sized robots, our design combines simplicity, low cost and compactness. We first detail our design and explain its key parameters. Then, we present our implementation and compare it with an omniwheel drive built with identical conditions and similar cost. Finally, we elaborate on the main advantages and drawbacks of our design

Permanent Magnet minimization in PM-Assisted Synchronous Reluctance motors for wide speed range

This paper presents a technique to modify the rotor lamination of a permanent-magnet-assisted synchronous reluctance motor, in order to reduce the magnet volume with no side effect on performance. A closed-form analysis, which is based on a lumped parameter model, points out that the magnet quantity can be minimized with a significant saving of material volume and cost. At a second stage, the risk of demagnetization is evaluated since the minimized magnets are thinner than the starting ones and work on lower load lines in their respective B-H planes. A feasible drawing is analytically defined, which is robust against demagnetization at overload, showing that the saving of magnet quantity depends on the maximum current overload and can be significant. The theoretical formulation is validated with finite-element analysis and experiments on a prototype machin

Position-sensorless control of permanent-magnet-assisted synchronous reluctance motor

The sensorless control of permanent-magnet-assisted synchronous reluctance (PMASR) motors is investigated, in order to conjugate the advantages of the sensorless control with full exploitation of the allowed operating area, for a given inverter. An additional pulsating flux is injected in the d-axis direction at low and zero speed, while it is dropped out, at large speed, to save voltage and additional loss. A flux-observer-based control scheme is used, which includes an accurate knowledge of the motor magnetic behavior. This leads, in general, to good robustness against load variations, by counteracting the magnetic cross saturation effect. Moreover, it allows an easy and effective correspondence between the wanted torque and flux and the set values of the chosen control variables, that is d-axis flux and q-axis current. Experimental verification of the proposed method is given, both steady-state and dynamic performance are outlined. A prototype PMASR motor will be used to this aim, as part of a purposely assembled prototype drive, for light traction application (electric scooter