PLC-Based Real-Time Realization of Flatness-Based Feedforward Control for Industrial Compression Systems

In this paper, we present a novel programmable logic controller (PLC)-based real-time realization of a flatness-based feedforward control (FFC) scheme. The proposed approach is applied to an industrial fuel-gas compression system which is used to supply fuel gas to the gas turbines in combined cycle power plants. Due to the increasing demand for fast operation point transitions with high performance and accuracy requirements, the currently applied decentralized proportional-integral-derivative controllers appear to be not appropriate any more. Hence, by means of system simulations, a new flatness-based FFC design has been shown to provide improved control performance. In this paper, we bridge the gap between simulation-based control design and practical applicability, in that, we present the real-time realization of the approach on a PLC. Furthermore, the PLC-based controller is tested on a hardware-in-the-loop platform running with a complex compression system model in real time. The results reveal that the flatness-based control design can be implemented on a real compressor system.