Electric motors are devices that convert electrical energy into magnetic energy and finally into mechanical energy. Electromagnetism is the basis of electric motor operation by generating magnetic forces necessary to produce either rotational or linear motion. For rotating electric motors, it is the interaction between the stator and rotor magnetic fields that creates motor torque to drive external loads.

Today, electric motors come in a wide variety of types, sizes, styles, winding topologies, magnetic flux loops, operating characteristics, and structural configurations to suit different applications. They have been used almost everywhere in the world, including industrial drives, household appliances, medical devices, electronic products, robots, drones, electrified vehicles, machine tools, spacecrafts, and military equipment. As one of the fastest-growing industrial sectors, electric motor manufacturing represents a major industry worldwide. According to the study conducted by the International Energy Agency [1.1], electric-motor-driven systems account for approximately 53% of total global electricity consumption, or 10,500 terawatt hours (TWh) per year, and emit a total of 6,800 metric tons of carbon dioxide. By 2030, energy consumption from electric motors is expected to rise to 13,360 TWh per year, ticking up CO₂ emissions to 8,570 million metric tons per year. End users now spend USD 565 billion annually on electricity used in these motor-driven systems and by 2030, that could rise to close USD 900 billion [1.2]. In the United States, motor-driven equipment accounts for 64% of the electricity consumed in the manufacturing sector. That is approximately 290 billion kilowatt hours (kWh) of power per year [1.3]. There are more than 40 million electric motors used in manufacturing operation [1.4]. In addition, more than 95% of electric motor’s life-cycle cost is the energy cost. In China, the total power consumption of electric motors is about 3 trillion kWh, accounting for about 64% of the total power consumption [1.5, 1.6]. It is estimated that improving the efficiency of all the world’s motors by just 1% would reduce the motor power consumption by 94.5 TWh of electricity and shrink their CO₂ footprint by the equivalent of 60 million metric tons per year [1.7]. This would significantly reduce the need for new power plants and push down the total environmental cost of electricity generation. There is no doubt that the continuous push for decarbonization will greatly increase global demand for more efficient electric motors.

The report that provides information on the industrial motor market growth, trends, and forecast during the period of 2020–2025 by Motor Intelligence was released in 2019 [1.8]. According to the report, the global market of industrial motors is expected to register a compound annual growth rate of 6.11% during 2020–2025 and reaches a market value of USD 64.25 billion by 2025. However, it is worth noting that this report did not consider the consequence of the COVID-19 pandemic that has severely upended global economy. According to World Trade Organization, the volume of world merchandise trade declined by 5.3% in 2020 as the COVID-19 pandemic disrupts normal economic activity all over the world and is expected to increase by 8.0% in 2021 [1.9]. Nevertheless, in the long term, the market will generate remunerative prospects for producers post COVID-19 crisis. Substantial advances in technology have opened up opportunities to develop and manufacture electric motors for a wide range of applications in industries, such as automation, automotive, agriculture, aerospace, construction, power generation, and other industrial sectors.