Standard power source have single phase AC power source, Three phase AC power source and DC source. Three phase power source is high precision three phase phantom load power source, it can be imulation of load while testing meter installations on-site or application in electrical laboratory and watthour meter manufacturer R & D. With color TFT touch screen, programmable wave form generation for voltage and current, every channel is independent, and generation of harmonics in current and voltage up to the 63nd. all channel voltage and current value can be setting and programmable. from 0 to 600V and 0 to 120A/500A/1000A, frequency from 40 to 70Hz, phase angle from 0 to 360.000, power factory -1 to 1.