Compressed air is an important medium for energy transfer in industrial processes. It drives various actuators, which create a large force for significant movements and a high operation speed. Thereat, these mechanisms are quite small, and the design is simple and reliable. They are applicable in food and pharmaceutical technologies. Compressed air systems belong to the largest energy consumers at such enterprises. They consist of several compressors, and the drive of one of them is powered by a frequency converter in order to save electrical energy. This is called a multiple air compressor system, and its operation is controlled by a separate controller – master controller. The paper discusses the results of developing the master controller design and its operation algorithm. As an additional informative signal in the developed design of the master controller, air flow rate measurements are used; additionally, the speed of the air flow rate variation is analysed.