The theoretical results for variable structure control systems can be fruitfully used for the design of control systems involving real industrial processes with widely time varying parameters.
Summary--This article presents the basis and conception of, and some experimental results obtained from, the automation of a hydroelectric power station. The principle of this automation, the purpose of which was to maximize the active power supplied by the station, requires a detailed analysis of the automatic water-gate control systems for the turbo-alternator sets. Because identification of these watergate systems proved tricky in view of the utilization conditions, their representation by a linear differential equation with widely time-varying coefficients emerges as a solution which is both realistic and convenient. In order to satisfy the constraints imposed, the controls for these systems may be synthetized by using the principles of variable-structure systems, the essential property of which is the insensitivity of performance to variations in the parameters of the controlled section. The general principles of variable structure control systems are presented and a procedure is given for the control law synthesis when the control action is restricted. Some experimental results of an automation system based on these algorithms are presented at the end of the article.