Model Predictive Control for Three Phase Power Factor Correction Circuits in Aircraft Applications

Abstract

Highly efficient and dense power electronic converters are an essential part of aircraft electrical systems. The Swiss rectifier provides an efficient application of AC-DC conversion. However, currently used conventional control strategies, such as carrier-based PWM control, have not been able to produce AC currents that meets aircraft power quality standards for the Swiss rectifier. Model predictive control is a control strategy that has recently become popular with the availability of powerful microprocessors and has the potential to improve power quality issues currently faced by the Swiss rectifier in aircraft applications. Therefore, finite control set model predictive control is used here specifically for current control of DC-switches in the Swiss rectifier. Work of the thesis consists of designing and optimizing a simulation model. The goal is to model the Swiss rectifier to operate with model predictive control and to limit input AC current’s total harmonic distortion to less than 5 % which would suffice for aircraft applications as per military standards. The developed phase-based model predictive controller is simulated with different cost functions and the resulting input current THD, harmonic spectrum and switching frequency are evaluated and compared.