Study Of Online Measurement And Stall Control By DSP In Compressors

The presence of compressor aerodynamic unsteady flow, control system is the leading problem of compressor. Based on the current research of unsteady flow, the improved modern control theory and the advanced control technology, the aim of this dissertation is to develop a stability management system which is combined with correlation measurement, digital signal process (DSP) and tip micro injection. It is used for online measurement, in-flight operation and safety for modern compressors with a new stability measurement called correlation measure. The experiments showed that the stability management system was able to detect an impending stall and trigger opening of the air-injection valve to avoid compressor stall.The dissertation is organized as follows: First, in order to find out whether the correlation measurement is good at catching the stall inception signals, the experiment of dynamic pressure signals online measurement is carried out; Second, based on the results of correlation measurement, the experiment of adding the tip micro injection shows that the air-injection could be desirable to extend the boundary of compressor stall. Third, the final result shows that the existing hardware as DSP control system can be employed along with the correlation method to provide effective stall management. The stall management system can potentially be used in compressor control and it is desirable to establish the stability limits of compressor without driving it to hard stalls.The results of all the experiments above show that following the flow decreased the correlation measurement might have the ability of generating a stall warning signal sufficiently in advance of spike inception, further more, the tip micro injection would improve the stall margin effectively.The system of tip micro air injection includes an electrical switch which might open and close the air-injection with DSP instantly.