New temperature test for synchronous machines

A novel temperature-test method for synchronous machines is described. The test machine is operated either as a motor at no load or as a generator supplying a reactive load, both with rated field excitation, while a second source is applied to cause full r.m.s. current to circulate in the armature winding. The test simulates a true temperature test in every respect, and is of special value for machines rated at power factors above 0.9. The new test may additionally be used to determine the machine efficiency at rated load.