A power generator for watthour meter testing equipment using digital phase angle control system

The author describes a new design of electronic power generator for watthour meter testing equipment (MTE) for testing heavy current watthour meters. This newly designed power generator is able to deliver a wide range of test currents by application of a digital phase angle control system without changing the turn ratio of the output transformer. The test current is delivered by only the phase angle signal from a sine wave generator without mechanical contacts. This testing equipment is able to simultaneously test 40 domestic watthour meters. The current output transformers can be of one range with respect to the rated current. The adjustment to the rated output does not require hardware owing to computer control, and can be made by program software. The accuracy of the testing equipment can be maintained by calibrating the digital power meter