Modeling and Control Law Optimization Design of Starting Process of the Three-Shaft Turboshaft Engine

The starting process of the three-shaft turboshaft engine is a complex dynamic process. Compared to the single-shaft turboshaft engine, the low-pressure compressor of the three-shaft turboshaft engine will occur the surge failures during the starting process. To ensure the compressor has sufficient surge margin, it is necessary to bleed air between the high-pressure compressor and the low-pressure compressor, which results in energy waste and efficiency decline. Thus, it is necessary to balance the safe operation and performance loss of the engine during the dynamic operation. In this paper, a starting model based on the component characteristics for the three-shaft turboshaft engine is established on the SIMULINK platform. The sequential quadratic programming (SQP) method is used to optimize the control law of the starting process considering several safety limit parameters. The optimized starting control law has a 16.2% reduction in starting time at the standard sea level atmosphere. Compared to the original control law, the bleed air of the starting process is reduced by 7.2%.