Designing a digitally controlled fuel system for an experimental small turbojet engine

This contribution presents a proposal and practical implementation of a digitally controlled fuel system for control of fuel supply into a small turbojet engine, iSTJ-21V. In the past, for the purposes of fuel metering to the engine MPM-20, which was a previous version of the iSTJ-21V, the servo valve LUN 6743 was used. However, this solution has several disadvantages such as increased strain on the fuel pump and non-linear characteristics. The new fuel control system was tested on a measuring stand and implemented into microcontroller platform and tuned during full operation of the engine. As microcontroller platform the 32 bit NXP LPC1768 microcontroller was chosen. The contribution consists of the principle of control of a small turbojet iSTJ-21V engine and a summary of the results in a graphical form. The main contribution of this work is to create a digitally controlled fuel system with sufficient accuracy control of fuel supply to the engine the need to increase its effectiveness and application of modern control algorithms at a higher level.