An integrated control technique for compressor operation

In the gas industry the control of the compression system has two primary objectives: the operation of the machine and also its protection against damage such as that following a surge cycle. The interaction between these two control actions can be strong, causing instability and oscillations. Moreover whenever the gas is recycled for surge protection, it is not delivered as final product and energy is wasted during its compression [1]. These observations provide the incentive for better integrated control. While many researchers have been working on the control of surge, not much has been done to improve the control of the performance or the integration between the two control objectives, even though this need has already been highlighted in the past [2]. This paper proposes a control scheme based on the characteristic map of the compressor, taking into account inlet disturbances. The proposed control solution is comparable to the state-of-the-art control solution under slow disturbance dynamics and allows a tighter pressure control during fast changing dynamics, reducing at the same time the proximity to the surge region. For this reason it represents a step forward in the direction of process control integration for compressor applications.