The measurement of transient torque and load angle in model synchronous machines

The paper deals with the development of equipment for measuring the torque and load angle of an electrical machine under transient conditions and its use in verifying some theoretical results. The equipment is used in conjunction with a `micro-alternator¿, which is a small machine specially designed to simulate a large generator. The torque meter uses resistance strain gauges mounted on a special coupling connected mechanically to the machine shaft. The load-angle meter operates by generating a succession of pulses which modulate the intensity of an oscillograph beam as it traverses a periodic wave. The experiments recorded relate to the following conditions: (a) Oscillations superimposed on steady operation as a synchronous machine. (b) Sudden short-circuit of an alternator.