Wide Input Voltage Non-isolated 6kVA Three Phase Aeronautical Static Inverter

In some specific occasions like aerospace power systems, the voltage amplitude and frequency of power supply range in larger field. In order to achieve the stable output voltage in amplitude and frequency, the static inverter of two-stage structure proposed, the first stage converter and the second stage converter have their own closed-loop control respectively.In this thesis a wide input voltage non-isolated 6kVA three-phase aeronautical static inverter is proposed with two-stage structuer. The first stage is Doul-Boost converter which provides a stable positive and negative DC bus voltage, the second stage is the separated three-phase Doul-Buck inverter which constitutes the output AC voltage of three-phase sinusoidal waveforms. Lossless snubber circuit in first stage realise the turn-off buffer of switch. Using Doul-Buck topology in second stage improves the reliability and operating efficiency of inverter circuit. The half-cycle hysteresis current control improves the output waveform quality and the response speed of system.This thesis analyzes the working principle of the wide input voltage non-isolated 6kVA three-phase aeronautical static inverter. The model of two stages are built respectively, their compensation style and design parameters are given. This thesis provides the main circuit and the control circuit design of two stages. It has a detail operating modal analysis of the lossless snubber circuit in first stage and then promots the usage to the other 5 kinds of non-isolated single switch converters.Finally, the system is simulated and experimented. The power loss in various parts of the system are analyzed and then proved by the thermal imaging. The efficiency curves under the different input voltages are analyzed. Simulation and experimental results show that this two stage static inverter achieves reliable work, meets the pre-set design target, verifise the correction of the theoretical analysis and control strategy.