Summary In this paper we provide an overview comparing induction motors (IMs) and permanent-magnet motors (PMMs) for electrical-submersible-pump (ESP) applications. The design and performance differences of the two types of motors are compared and discussed. The PMM advantage and unique applications are highlighted. The requirement of a different control strategy to operate a PMM is described. Some key safety aspects that field engineers need to be aware of with PMMs are also addressed in this paper. The information we present includes a literature review and the latest research and development results. We cover the operating principles of the IM and the PMM, selection of permanent-magnet materials, operating frequency, stator windings, and magnetic poles. PMMs offer better efficiency, higher power-factor performance, and compactness. Ideal applications include slim-well applications, through-tubing rigless deployment, Y-tool completion, and electric-submersible-progressive cavity pumps (ESPCPs). We will also shed some light on why conventional IMs cannot be used to drive ESPCPs directly without speed-reduction gearboxes. It is very likely that the use of PMMs will increase for ESP applications in the near future, and this will require engineers to acquire a basic understanding of this technology. This paper intends to provide a high-level comparison between IMs and PMMs in the ESP industry.
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Xiao et al. (2018) studied this question.