The Impact of High Temperature on Motor Performance and Countermeasures
Jun 16, 2025
In modern industrial automation, motors serve as core driving components and are widely used in various equipment and systems. With continuous technological advancements, the performance requirements for motors have become increasingly stringent. For instance, in high-temperature environments, elevated temperatures can significantly affect motor performance, efficiency, and lifespan, as detailed below:
1. Reduced Efficiency
Increased Resistance: The resistance of motor windings (copper wires) rises with temperature, leading to higher copper losses (I²R) and reduced efficiency.
Changes in Iron Losses: High temperatures may exacerbate eddy current losses and hysteresis losses in the core (especially in permanent magnet motors), further decreasing efficiency.
2. Decreased Output Power
Thermal Limitations: Motors are typically designed based on rated temperatures. Under high temperatures, heat dissipation capacity declines, potentially forcing derated operation (reducing output power) to prevent overheating.
Demagnetization of Permanent Magnets (PMSMs): High temperatures can weaken the magnetic properties of permanent magnets, reducing magnetic field strength and consequently lowering torque and power output.
3. Accelerated Insulation Aging
Insulation Material Lifespan: High temperatures accelerate the aging of motor insulation materials (e.g., enameled wires, slot insulation). Empirical rules indicate that insulation life halves for every 10°C temperature increase (Arrhenius Law).
Breakdown Risk: Prolonged exposure to high temperatures may cause insulation cracking, leading to short circuits or ground faults.
4. Bearing and Lubrication Issues
Lubrication Failure: High temperatures reduce the viscosity or cause oxidation of lubricating grease, resulting in poor lubrication and increased bearing wear.
Mechanical Deformation: Thermal expansion of bearings or shafts may alter fitting clearances, causing vibration or seizing.
5. Impact on Control Systems
Sensor Drift: Temperature-sensitive components (e.g., thermocouples, Hall sensors) may produce erroneous readings, affecting control accuracy.
Electronic Component Failure: High temperatures reduce the reliability of drive circuits (e.g., IGBTs, capacitors), increasing failure rates.
6. Other Potential Issues
Thermal Stress: Differences in thermal expansion coefficients may cause structural deformation (e.g., between the stator and housing).
Cooling System Overload: Forced cooling systems (fans, liquid cooling) may operate at full capacity for extended periods in high-temperature environments, shortening their lifespan.
Countermeasures
Optimized Heat Dissipation: Enhance ventilation, adopt liquid cooling, or implement heat pipe technology.
Material Selection: Use high-temperature-resistant insulation materials (e.g., Class H insulation) and high-temperature lubricants.
Temperature Monitoring: Install temperature sensors for overheating protection or power derating.
Environmental Control: Avoid operating motors in enclosed or high-temperature areas; install additional cooling systems (e.g., air conditioning) if necessary.
Conclusion
High temperatures comprehensively affect a motor’s electrical performance, mechanical reliability, and control system stability. Proper thermal design and temperature management are crucial to ensuring stable motor operation in high-temperature environments. If your application requires prolonged operation under high temperatures, it is advisable to use motors specifically designed for such conditions to ensure sustained and reliable performance.
Zhonggu Weike Power Technology Co., Ltd. is a National Specialized, Sophisticated, and Innovative Enterprise specializing in the R&D, manufacturing, and application of special motors for harsh environments, including vacuum, high-temperature, cryogenic, and radiation conditions. Our products are widely used in aerospace, satellite communications, space observation, biomedical engineering, and genetic sample storage.
With a professional team in technology, manufacturing, and service, as well as Asia’s most comprehensive environmental and dynamic transmission testing facilities, we are committed to providing expert, high-quality solutions for every customer.