Modulated Model Predictive Control for Reliability Improvement of Extremely Low Frequency Power Amplifier via Junction Temperature Swing Reduction

In the extremely low-frequency electromagnetic wave communication system (ELFEWC), the power amplifier is required to output extremely low-frequency voltages, which makes the junction temperature swing of the power device significantly large. It brings great challenges to the overall reliability of the system. In this paper, an active thermal control strategy based on modulated model predictive control (M2PC) is proposed for the extremely low-frequency power amplifier (ELFPA) in ELFEWC to reduce the junction temperature swing of the power device and extend the life of ELFPA. Specifically, the proposed M2PC can guarantee the output accuracy of the power amplifier with the fixed switching frequency. Furthermore, the appropriate switching frequency is selected by considering the tradeoff between junction temperature swing and total harmonic distortion (THD) to improve the reliability. The proposed control strategy has the advantages of reducing the junction temperature swing of the power device while meeting the output accuracy. Finally, simulation and experimental results of a 10kW ELFPA demonstrate the effectiveness of the proposed control strategy on the junction temperature swing reduction of the power switch.