Pipeline energy management: using VFDs and sync-transfer control systems

Variable speed drives (VSDs) and programmable logic controllers (PLCs) in oil and gas facilities and pipeline pumping station applications are reviewed. VSDs and PLCs give pipeline operators a wide range of choices with regard to controlling flow rates and pressures; just as importantly, they give operators the ability to effectively control their power use. The latter takes on added importance in view of the deregulation of electrical utilities, and the likelihood of wide swings in regional power rates and exposure to market demand prices. Consequently, many oil and gas companies are applying variable frequency drives (VFDs) as the VSD of choice for pipeline pumping and facilities applications for controlling energy savings and for transfer control with soft starting. This article explores the underlying reasons for the rising popularity of VFDs and PLCs, reviews the basics of oil and gas facilities operations, provides an update of VFD technology developments, and summarizes some lessons learned from typical VFD project experiences. It concludes that there are hundreds, if not thousands, of multiple unit pumping stations in Canada and the United States that are ripe for VFD sync-transfer applications, and that in many instances the energy savings alone could justify and pay for the installation of VFD and associated PLC controls. 2 refs., 6 figs.