Shifting from Reactive to Pre-emptive Thermal Management

Thermal management in electric vehicles isn’t just about comfort, it’s about survival. Every 10 degrees of temperature rise halves the insulation resistance on motor windings, and even a single undetected hot spot can cause catastrophic, permanent motor deterioration. A new article by Andrew Cross, Chief Innovation Officer at Helix, explores why the industry’s reliance on direct temperature sensors is fundamentally limited, and why sophisticated electrothermal modeling represents the future of EV thermal management.

The challenge is multifaceted. Heat generation comes from resistance (copper’s resistance increases 40% with every 100-degree temperature rise), eddy currents in stator iron, viscous bearing losses, and high-frequency inverter switching. Capturing real-time temperature readings across the entire motor at the granularity needed to identify hot spots is technically complex. Direct sensor-based approaches—thermistors, thermocouples, infrared sensors—introduce wiring complexity, multiple points of failure, and potential efficiency trade-offs.

The alternative is coupled electromagnetic and thermal modelling. By developing a sophisticated model of motor behaviour across electrical and thermal conditions, engineers can pair this with sensors already deployed in the system – current, position, and coolant temperature sensors. This indirect method eliminates the need for intrusive sensor networks while enabling something direct measurement cannot: predictive capability. A sufficiently sophisticated model can anticipate hot spot formation and instruct thermal management systems to maintain continuous optimal performance. This shift from reactive to pre-emptive thermal management is critical for maximizing efficiency, performance, and motor longevity, making electrothermal modeling not a substitute for sensors, but a fundamentally superior approach.

Read the full article: Shifting from Reactive to Preemptive Thermal Management – Tech Briefs

This article first appeared in the April, 2026 issue of Battery & Electrification Technology Magazine (Vol. 50 No. 4).