The application range of general-purpose inverters and servo drive systems continues increasing through improvement in performance, function, and flexibility. Inverter size has been reduced remarkably to approximately one-tenth in volume in the last ten years. The application of transvector control without sensor and auto-tuning has rapidly improved their performance and ease of use. This paper outlines their technical developments and future prospects.

The new general-purpose inverter has been developed to meet market needs for high starting torque, low torque ripples, low noise, convenient operation, etc. The main features are improved torque characteristics using torque vector control, easy adjustment by auto-tuning function, and low noise by IGBT application. Models not more than 22kW were much reduced in size by loss reduction and efficient cooling. This paper introduces an outline of its specifications, features, construction, and keypad panel.

This inverter aims at use for simple speed regulation such as small fans and pumps, mini conveyors, and replacements for mechanical variable-speed drives for which a growing need is expected. New technologies such as combined metal substrate with different insulation, heat sink made by press machine, and metal QFP has reduced the volume to about 50% of the former series. All the models are equipped with IGBTs and motor noise is low as in commercial power operation. Power and control circuit parts all molded in resin are resistant to the environment. This paper outlines its features, specifications, elementary technologies for downsizing, and its applications.

The FVR-E7S series has now a full line ranging from the minimum 100W to 3.7kW, including 400V AC input first for compact inverters. It has been reduced in size using the custom LSI for both of digital and analog circuits, and also it uses combined metal substrates with superior cooling characteristics and our original protective function, and has realized very low noise operation by means of high carrier PWM using IGBTs. High-speed processing of the current-limiting function with 32-bit DSP realizes powerful, persistent stable operation under an impact load or a restart at power restoration in instantaneous failures.

The FRENIC5000M2 series for AC spindle drive was favorably noticed by the market. With the advancement of machine tool performance and function and growing need for combined machining, there has been increasing demand for its enhanced performance and function. Fuji Electric has developed FRENIC5000M3 series with high-speed torque limiting control that realizes short acceleration and deceleration time and slip compensation control. This series fully enables machine tools to execute combined machining with an option for two-spindle synchronization concurrently developed. This paper outlines its specifications and features.

Inverters have been spreading from simple speed control for fans and pumps to sophisticated applications. Examples of the latter are elevators and centrifugal separators with heavy inertia. A problem in these equipment is how to deal with regenerated energy during braking. Formerly, this regenerated energy was consumed as heat by the resistance discharge brake circuit in the inverter DC circuit. This paper introduces a regenerative braking unit, as inverter peripheral equipment, that can efficiently return regenerated energy to the power source.

Inverters and AC servo systems have been developed to compact, high precision, high response, multifunction, variable-speed drives. Systems composed of these and programmable controllers make fine control possible and are applied effectively to various industrial equipment. This paper introduces applications of the transvector controlled inverter FRENIC5000VG3 and AC servo system FALDIC to film, metal, and fiber manufacturing equipment.

Recent industrial circles, aiming at reduction in labor and energy, have increasingly used variable-speed operation of three-phase squirrel-cage induction motors with inverters. To meet the market needs, Fuji Electric has produced various series of motors for inverter drive, which are favorably noticed in the market. From among special motors for inverter drive, this paper introduces the specifications and features mainly of special motors for FRENIC5000VG3 which have reduced size and advanced functions compared to the former models.

Seven years has passed since Fuji Electric put on the market industrial heating inverters as small size, high performance, easy to use, general-purpose articles. Their popularity in the market has risen and uses have rapidly increased. To meet various uses of general-purpose heating inverters, a series of six models has been completed. Further, thin, drop-in type heating inverters with a small capacity and usable for simple heating application have been newly developed. To meet diversified uses, both are designed to supply high frequency current efficiently and stably with a small, lightweight construction.

In conveyor systems, packaging machines, and other general industrial equipment, the diversification of market needs demands that inverters, servo systems, and other variable-speed systems should have advanced functions and high performances. The major demands are advancement of functions to meet system diversification, freedom from drift, downsizing, and labor reduction in system buildup. To meet these requirements flexibly, Fuji Electric has developed a digitally controlled variable-speed system "digital ES motor." This paper introduces its functions and features.

Servo systems are used for various general industrial equip-ment to meet demands for advanced performance and functions. Their system configurations range from comparatively simple systems realizable with a single axis to complex systems that requires multiple axes. These multi-axis systems demand that the servo amplifier should be able to transmit more information without increasing the burden of the upper level equipment. This paper introduces the functions and features of the special servo amplifier FRB series for multiple axes that interfaces the upper level equipment with a bus connection system.

There has been a growing trend among automation and labor reduction technologies towards sophistication and requirement diversification, which demands that servo systems as their base should be of higher multifunction and flexibility. A communication function with upper level controllers such as personal computers and programmable controllers and a point-to-point motion control function are particularly desired as functions for the actuator side. This paper introduces the functions and features of the FALDIC series developed as a general-purpose position control servo to meet these requirements.

The POSIROL-JIN is a traveling cutting system that cuts conveyed material in fixed lengths or at fixed distances from each mark. The POSIROL-CAM is a synchronous position control system that synchronizes cam operation with the main shaft rotation with a registered cam pattern, of which position can be set at every one degree corresponding to 0 to 359 degree of the main shaft. This paper gives an outline of these two models.

The machine controller MC is a general-purpose controller for machine control in which a multi-axis control section for a main shaft and more than one servo shaft, a programmable controller section, and a CRT and operation panel control section are unified. Using this MC, the installation space and number of wires of a machine can be reduced and operation diagrams on the CRT can easily be drawn up, which effectively improves flexibility. This paper outlines the specification, system configuration, and applications of the MC.