Abstract : This paper applies an ABB ACS604 frequency converter to implement closed-loop control of an air compressor, replacing the pressure relay control for loading and unloading. This reduces the process impact caused by large air pressure fluctuations, extends the compressor's service life, reduces energy waste, and improves the production environment. Keywords : Frequency converter, air compressor, closed-loop control, energy saving 0 Introduction An air compressor is a device that compresses atmospheric pressure into high-pressure, energy-storing gas. Compressed air pressure is a critical process parameter in industrial production. Jiangxi Changli Automotive Leaf Spring Co., Ltd. requires maintaining the compressed air pressure between 0.68 and 0.78 MPa due to production process requirements. The existing control method uses a pressure relay to control loading and unloading. When the compressed gas pressure reaches 0.78 MPa, the air compressor unloads, and the pressure begins to drop; when the pressure drops to 0.68 MPa, the air compressor loads, and the pressure begins to rise. The frequent alternation between loaded and unloaded operation causes significant fluctuations in the air compressor's current, increasing its energy consumption. The increased piston impact force during loaded and unloaded operation also drastically reduces the compressor's lifespan. Furthermore, the harsh noise generated during loading severely impacts the operator's health and disturbs the surrounding environment. Therefore, it is necessary to modify the existing control method. We selected an ABB ACS600 frequency converter and pressure transmitter for PID closed-loop control of the air compressor, achieving stepless speed regulation and soft start/shutdown. This significantly reduces energy consumption, lowers noise levels, improves the surrounding environment, extends the compressor's lifespan, and enhances the company's market competitiveness. [b][align=center]For details, please click: Application of ABB ACS600 Frequency Converter in Closed-Loop Control of Air Compressors[/align][/b]