Life Cycle Energy Cost Assessment for Pump Units with Various Types of Line-Start Operating Motors Including Cable Losses

Vadim Kazakbaev,Vladimir Dmitrievskii,Safarbek Oshurbekov,Dmitry Golovanov,Vladimir Prakht

doi:10.3390/en13143546

Vadim Kazakbaev, Vladimir Dmitrievskii + Show 3 more

Open Access

https://doi.org/10.3390/en13143546

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Journal: Energies	Publication Date: Jul 9, 2020
Citations: 7	License type: CC BY 4.0

Affiliation: Ural Federal University, University of Nottingham

Abstract

The paper presents a comparative analysis of life-cycle energy consumption for three different types of 4 kW line-start motors used in a pump unit with throttling: the most widely used induction motor with IE3 efficiency class, line start permanent magnet synchronous motor with IE4 efficiency class and line start synchronous reluctance motor with IE4 efficiency class. The operating cycle for pump units with constant flow is considered for the above-mentioned types of motors taking into account not only the losses in the pump and motor, but also in the power supply cable. It is shown that the line start synchronous reluctance motor without magnets has the highest efficiency over the entire considered loading range. However, its power factor is lower than that of the synchronous motor with magnets and therefore it has more significant losses in power supply cable. Despite this disadvantage, the line-start reluctance motor is a good alternative to widespread induction motor since it allows saving of approximately 4000 euro more than the latter during the 20 years life cycle. It also provides similar savings in comparison to the permanent magnet synchronous motor, but unlike it, it does not have costly rare-earth materials in the rotor.

Highlights

Nowadays, most of the drives with the direct start from the mains power supply utilize induction motors (IM) with aluminium squirrel cage
Using the results obtained in the previous sections, we compared the energy consumption of the pump drive with various motors: LS-synchronous reluctance motors (SynRM), line start permanent magnet synchronous motors (LS-PMSM) and IM motor
The present paper provides a comparative analysis of the energy consumption of electric motors

Summary

Introduction

Most of the drives with the direct start from the mains power supply utilize induction motors (IM) with aluminium squirrel cage. Synchronous reluctance motors (SynRM), which have no magnets and no short-circuited startup winding in the rotor, and are powered by a variable frequency drive (VFD) are the good alternatives to IM [17,18,19,20,21] They meet the criteria of IE4 energy efficiency [22,23] and IE5 [19,24,25], according to the standard IEC 60034-30-2 «Rotating electrical machines – Part 30-2: Efficiency classes of variable speed AC motors (IE-code)». There are IE4 energy efficiency class synchronous reluctance motors that are powered directly from the mains power supply, the rotor of which is manufactured with a short-circuited startup winding (line start synchronous reluctance motor, LS-SynRM) [28,29,30,31]. The proposed calculation method can be used for choosing the type of electric motor in pumping systems

Evaluating

According

PumpThe

Cable Losses Depending on Motor Power Factor

Electric Energy Consumption Results and Discussion

Findings

Conclusions