Harmonic Control for Variable-Frequency Aviation Power System Based on Three-Level NPC Converter

At present, three-phase 115V/360-800Hz variable frequency AC power system is mostly used in the main power system of More-Electric Aircraft. With the increase of EMA (Electro-Mechanical Actuator), EHA (Electro-Hydrostatic Actuator), DC/DC power supply and power electronic devices in More-Electric Aircraft, harmonic and reactive power problems are brought, which seriously affect the power supply quality of variable frequency power supply for aircraft. According to the characteristics of high frequency and wide range of aviation variable frequency power supply, this paper studies a three-level active filter which can effectively improve the power quality of aviation variable frequency power supply system. This paper analyzes the working principle of the diode clamped three-level topology active filter, and deduces its mathematical model; proposes the frequency detection of the aviation variable frequency power supply based on the improved Rife method; the ip-iq method based on the instantaneous reactive power theory, accurately detects the harmonic current of the aviation variable frequency power supply system; uses the quasi PR controller to track the current, and improves the harmonic suppression effect. Finally, the experimental hardware platform is built to verify the feasibility of the proposed control strategy.