Maximizing Efficiency: Understanding Motor losses in PM Synchronous Motors

As concerns about energy consumption and environmental impact continue to grow, many companies are looking for ways to make their operations more sustainable. In the quest for optimal efficiency, the importance of electric motors cannot be overstated. With standards like IEC60034-30-1 guiding the industry towards higher efficiency systems. This article delves into motor efficiency and electric motor losses, specifically in Permanent Magnet Synchronous Motors (PMSM) and explains how our expertise can help you achieve optimal performance.

The search for optimal efficiency

Magnetic Innovations is committed to providing top-tier solutions, particularly in the realm of higher efficiency electric motors. In the search for optimal efficiency by customers we try to understand the actual application and its sweet spot and support the customer with a motor that can be integrated for optimal overall efficiency of the total solution.

To gain this optimal overall efficiency we are using high efficient permanent magnet torque motors. As discussed in our ‘Radial vs. Axial flux motor’ article we believe that the radial topology of our motors benefits from a couple of physical advantages.

During the integration of our motors in the customer application, we can take advantage of their high torque property and aim for a simple, reliable, and energy-efficient direct drive application instead of a geared solution.

In this manner we skip potential gearbox losses and reduce maintenance.

Importance of motor efficiency

To further illustrate the importance of motor efficiency, the IEC60034-30-1 standard provides a classification system for the efficiency of electric motors. The accompanying graph from this standard showcases the efficiency levels (IE1 to IE4) for various standard motor sizes and types.

Higher IE levels indicate greater efficiency, with IE4 representing the highest efficiency motors currently standardized, with IE5 planned. This classification helps customers understand where their motors stand in terms of efficiency and guides them in selecting motors that will reduce energy consumption and operating costs.

Motor Losses: an overview

Every electric motor, including permanent magnet synchronous torque motors, inherently has losses. These losses occur in both the electrical and magnetic parts of the motor, primarily within the copper windings and the steel core.

The losses in the windings can be calculated using Ohm’s law: P = I²R, where P is power in Watts, I is current in Amperes, and R is resistance in Ohms.

The steel core losses are more complex and consist of three main components: hysteresis losses, eddy current losses, and excess losses.

Minimizing Motor Losses

To minimize both electrical and magnetic losses, our motors are designed with several key strategies in mind:

  • Electrical Loss Reduction: We lower resistance (R) by using a high filling factor in the stator slots and short, concentrated windings.
  • Magnetic Loss Reduction: We use high-quality laminated steel, ensure evenly distributed magnetic flux density in the core, and design short magnetic flux paths.

Optimal efficiency is achieved when electrical and magnetic losses are balanced. However, these losses are application-dependent, varying with the required torque (=current in the motor) and speed (=flux in the motor). Therefore, an application-optimized motor design is essential for high overall efficiency.

The role of cooling in reducing motor losses

Even when using high efficient motors, appropriate thermal management can make or break the final efficiency. A mechanical design that implements a good thermal path for the motor to dissipate heat away from the stator windings is very important.

Improper cooling can lead to unnecessary temperature rises, impacting efficiency by increasing winding resistance (R) and decreasing the magnetic field strength of the permanent magnets (H). Both temperature dependant physical phenomenon will decrease the efficiency.

Therefore it is recommended to thoroughly study your thermal conductivity capacity and incorporate an appropriate thermal path into your final application design.

Conclusion electric motor losses

Understanding and addressing electric motor losses are fundamental to achieving optimal efficiency in torque motors. By leveraging innovative design strategies, Magnetic Innovations delivers high-performance solutions. These solutions prioritize factors like resistance reduction and effective cooling, resulting in efficiencies reaching up to 94%.

For businesses seeking to enhance their applications with cutting-edge torque motors, Magnetic Innovations offers a standard range of Electric Motors, tailored solutions and the expertise to unlock the full potential of your systems.

Sounds good? Feel free to contact us and discover what is possible in your application!

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