Inverter Current Sensor Thermal Prediction for Dynamic Power Derating

The patent changes the protection parameter from time-based current limits to temperature-based control using a thermal model. The controller predicts current sensor temperature based on thermal parameters and operating conditions, then adjusts current limits dynamically according to predicted temperature rather than applying fixed time-based de-rating. This resolves the contradiction by maintaining reliability through accurate temperature prediction while avoiding unnecessary productivity loss.

The patent creates a virtual copy of the current sensor's thermal behavior through a thermal model that replicates temperature characteristics without physical sensing. The model uses thermal parameters (thermal resistance, thermal capacitance) and operating conditions to predict temperature, eliminating the need for physical temperature sensors on current sensors. This resolves the contradiction by achieving accurate temperature monitoring through mathematical modeling rather than direct physical measurement.

The patent transitions from static conservative current limits to dynamic current limits that adapt to real-time thermal conditions. The controller continuously predicts current sensor temperature using the thermal model and adjusts current limits dynamically based on predicted temperature and cooling conditions. This resolves the contradiction by allowing higher power output when thermal conditions permit while maintaining reliability when temperatures approach limits.