This paper describes recent progress in motor application technologies for industrial plants. Remarkable achievements are advanced IGBT inverters for variable-speed drive systems, open and distributed control systems, developments of advanced control technology, and engineering support systems for plant engineering.

This paper describes the basic concept, key components, and future development of Fuji Electric's integrated control systems in industrial applications of motors. To realize high-quality, low-price systems utilizing open technology, Fuji Electric is tackling the development of the MICREX-AX system in compliance with the development concept of openness and flexibility and distributed control system using the PROFIBUS in the open environment, which are outlined in the paper.

Fuji Electric has marketed three-level inverters with a unit a capacity of 1,200kVA using IGBT elements. Large capacity drive uses multiple three-level inverters, and medium capacity drive uses two-level inverters which have been supplied in great numbers. Thus the line of large and medium capacity variable-speed drive for industrial plants has much developed. In addition, the setting and monitoring system has been improved, open transmission has been realized, and some of plant control functions have been incorporated. Our goal for the future is increase in inverter output and voltage, and advance in intelligent functions.

Fuji Electric has promoted studies, development, and practical use of the whole field of advanced control theories. This paper takes up a speed control system which has been recently put to practical use by equivalently producing model following control with a disturbance observer. Also it refers to technologies under development, such as vibration suppression control for a system of two inertia masses with a small inertia ratio, where vibration suppression is said difficult, and application of simple adaptive control to speed control in which changes in response to modeling errors are small.

Although industrial plants have opposite problems of increasing requirements and demands for lower cost, they are still becoming sophisticated and complicated. The quantity of information in engineering processes has increased and posed a problem that we need an efficient, rational support environment. To solve this problem, Fuji Electric has developed and practically uses a support system that enables common use of engineering information and group engineering based on visual displays. This paper outlines its system constitution and various support functions.

In recent mill drive systems, variable-speed AC drive has come into wide use. Cycloconverter drive with synchronous motors is used for reversible hot-rolling mills, and PWM inverter drive with induction motors is used for small and medium continuous rolling mills. This paper describes the features of each drive.

The active equipment investment overseas has widened product quality and price competitions globally, and there are growing demands for lower price plants, higher productivity, maintenance and labor reduction. To meet these needs, Fuji Electric has enhanced speeds and functions of electrical system components such as programmable controllers, human communication interfaces, and drive systems, and configured a new system. This paper outlines the new drive control system and the features of main process control technologies.

This paper describes recent key technologies considered particularly important for control systems for pulp and paper, textile, and film plants. Taken up are technologies to deal with harmonics and instantaneous voltage drops, to cope with torque pulsation when induction motors are used for winders, and to prevent the influence of noise on electronic equipment. Also introduced are a maintenance support system to reduce labor for maintenance, a control system for auxiliary machines such as fans and pumps, and an up-to-date scanner system for spinning machines.

In recent industrial plants with motor applications have contained computers, programmable controllers, intelligent devices, and diagnostic equipment, and whole plants have advanced in function and become complicated. To operate and monitor such plants optimally, sophisticated and complex measures are required, and therefore, human communication interfaces (HCI) play an important role. This paper outlines those HCI, fault monitor systems, operating condition monitors for operation support systems, and maintenance support system FORS series used in steel mills.

Recently, plant engineering to provide functions and quality matching user needs at the lowest price and within the shortest lead time has been in great demand. This paper outlines the contents of engineering, new devices to reduce prices, and techniques of project management, focusing on engineering for industrial plants with motor applications.