Surge detection and control in centrifugal compressorsCentrifugal compressor are inherently complex functions that demand specialized knowledge and expertise in machinery dynamics, control systems, and process behavior. Achieving effective control involves the development of sophisticated algorithms, robust fallback mechanisms, and custom-engineered systems capable of executing high-speed computations for optimal turbomachinery performance. This chapter outlines the foundational concepts, including the dynamic compressor map, operating envelope, surge cycle characteristics, and methods for surge detection. It further explores the roles of antisurge and performance controllers within a comprehensive control strategy, detailing antisurge response mechanisms and advanced control functionalities such as loop decoupling, load sharing, performance override, limiting loops, and fallback operationsFallback modes. Additionally, the chapter addresses key design and operational considerations for recycle piping and valve sizing, hot-gas bypass valve specifications, and instrumentation requirements critical to reliable surge management.