A study on saving energy technology with regulating voltage of induction motor during light loads

The startup of oil-pumping units need overcome a large starting torque, but it works with light loads during long-term production, therefore the power factor and efficiency of motor is low. A saving energy control scheme is presented according to analyzing the features of saving techniques. In order to make motor running under optimal state the scheme regulates voltage by obtaining the optimum voltage ratio. A new IGBT chopping circuit and PIC microcontroller control circuit are also designed for electric test, soft-start of motor and protection. This new IGBT chopping circuit reduces two IGBT comparing with conventional circuits. The stimulation for the chopping circuit and control scheme has been conducted. For the static saving energy algorithm does not reduce the system dynamic features, this paper analyzes and validates the dynamic capability of the system. The electro-economizer discussed in this paper has been used for oil-pumping unit motor in oil fields and does reach expected target