Christoph H. van der Broeck, R. D. De Doncker
Oct 11, 2020
2020 IEEE Energy Conversion Congress and Exposition (ECCE)
This work proposes an active thermal management for three-phase IGBT-based inverters that estimates adaptively the maximal feasible peak current and operates the inverter safely at enhanced peak current rating. The active thermal management only requires processing a compact electrothermal real-time model and NTC-temperature information. Thus, it is applicable on most state-of-the art drive systems with small software modifications. The introduced method uses two technologies to increase the peak power rating dynamically: First, it estimates the coolant and junction temperature to adaptively determine the maximal peak current capability that increases at low coolant temperature. Second, it takes advantage of the thermal-impedance frequency-response function Zth(jω) that decays with higher frequencies in almost all power modules. This effect allows operation with larger peak current and the associated losses at higher excitation frequencies without exceeding the maximal junction temperature. With the introduced method, state-of-the-art drive inverters can operate safely at up to 200 % overload current across a wide speed range. This supports the development of highly reliable drives with increased base speed range and power density that save space, cost and resources.