An Approach For Saving Power of ESM With Long Cable by Control Frequency Based on Sensor-Less Estimating Temperature

An approach for saving energy consumption of the electric submersible motor (ESM) has been proposed based on combining the thermal field model with electrical control. For decreasing the high energy consumption that has become increasingly serious in oil fields, one of our works is to increase the identification accuracy of the ESM temperature by overcoming the influence of the long cable. The thermal field model of the long cable has been derived and used to correct the equivalent circuit of the ESM first; then the procedure that can be used to identify the rotor temperature is given based on improving the calculation accuracy and efficiency of the rotor slot harmonics. The control rule for modulating the inverter frequency to match the actual oil production was simulated by summarizing the experiment results. Theory analysis and experiments denote that the average identification error of the rotor temperature has been controlled within 1° C and the average power consumption of the ESM may be decreased for about 12% by the proposed approach. This work can effectively reduce the power consumption and provide overheat protection of the ESM.