Research On Control Strategies Of Aviation Fault Tolerant Generation System With High Reliability

With the development of more-electric and all-electric aircraft, the electrical loads are becoming key loads of the aircraft. Thus, the aviation independent power supply with high reliability is the premise of the aircraft safety. The high reliability means that the output DC voltage remains constant when the loads or speed changes even when one phase of the generator is open circuit or short circuit. So that the electrical equipment can operate normally.Firstly, the three-phase four-leg topology is proposed as the main circuit topology of the fault tolerant generator system by comparing the advantages and disadvantages of present various fault tolerant technologies. The control strategy of the generation system to remain output DC voltage constant when the loads and speed changes or one phase faults by analyzing the mathematical model of the FTPMM(fault-tolerant permanent magnet motor) and the energy conversion relationship of the generation system. The fault diagnosis and processing methods are also analyzed in this paper. Based on the theories, the simulation model of the generation system is set up to verify the control strategy.The hardware experiment platform is set up which mainly includes the control cuicuits and power circuits. The control circuits use TI's TMS320F2812 DSP as the core, and use Lattice's CPLD-M4A5 as the integrated fault handling unit. The power circuits use Mitsubishi Company's IPMs as the powet divices. The software procedures of the control strategy use C language which maily include fault diagnosis and control algorithm under normal state and fault state. Based on the hardware and software, the whole fault tolerant generation system was debugged.Experimental results verify the feasibility and effectiveness of the constant voltage control algorithms of the generantion system.