Abstract: This paper analyzes the operating parameters of pumps in atmospheric and vacuum distillation unit after impeller cutting. According to the site conditions, the pump that needs frequency conversion modification is selected when the motors are reconfigured. Through increasing the capacity of 6300/690V transformer on the spot and making use of the reserved space for distributing rooms, the feasibility of frequency conversion modification is confirmed. Meanwhile, the paper analyzes the investment income and existing problems of the project and puts forward suggestions for the application prospects of speed regulation by 6 frequency conversion to 690 V motors.

Key words: high temperature oil pump, medium motor, impeller cutting, frequency conversion modification