A comparative study of fixed speed vs. variable speed control of a series configured pipeline pumping application

Series pumps are used to boost oil flow in pipeline applications. Motors for these applications can be used in numerous configurations, both fixed speed and variable. Using operational data from a large pipeline company´s historical database, various configurations will be investigated and analyzed. A typical three electrical motor series pumping configuration with different control methods will be compared for efficiency, reliability, total life cycle cost, and operability. The following configurations will be studied: . Three motors at fixed speed . Two motors at fixed speed with one motor modulating pressure with variable speed control . Three motors all controlled at variable speed Conclusions will also include the company´s actual experience with implementing the above different types of controls based on existing electrical infrastructure and process control issues.