Analog computer study of wind-tunnel drive

PRIOR to the installation of a large wind-tunnel drive rated 110,000 hp (horsepower) continuously and 132,000 hp for one hour, an analog computer study was made of the drive and its control. Although considerable previous experience had been acquired in the design of this type of drive, two factors made it desirable to examine the system on the computer. One factor is the large power usage of the drive and the length of time involved in acceleration and deceleration at a rate acceptable to the electrical utility. These considerations prohibited excessive tune-up adjustments and testing. The other factor is the transient current in the d-c machine during switching. It was necessary to determine that this current would not exceed circuit-breaker settings.