Online Harmonic Reduction for Aircraft Electrical Power Distribution System With Global Phase-Shifted Carrier PWM

The penetration rate of power electronics converters (PEC) within onboard electrical power distribution systems  (EPDS) has been rising for years due to the trend of moving towards more electric aircraft (MEA) and all electric aircraft (AEA). Digital control and pulse width modulation (PWM) of these devices give rise to the electrical harmonics within the EPDS. Phase-shifted carrier PWM (PSC-PWM) has been a well-established concept for cascaded/paralleled PECs to eliminate certain harmonic components. However, when multiple PECs work cooperatively with different power ratings in the EPDS, an exhaustive system-level analytical model accurate to switching behavior is difficult to acquire and solve in real-time. In this work, a Simulated Annealing-based global optimization method is proposed for further enhancing the waveform quality at the EPDS transmission bus by tuning the PSC offset angle of the PECs directly according to the total harmonic distortion (THD) value measured online. Simulation and experimental results are given with a three-port system to verify the proposed scheme.