Adaptivolt

A Comparison of AdaptiVolt™ and Line Drop Compensation Conservation Voltage Regulation Implementation Methodologies
Tom Wilson, PCS UtiliData Spokane, WA December, 2010 tion on those feeders[4]. (Snohomish PUD has since implemented CVR on all of its distribution feeders.) In 1990 BC Hydro launched a program which included load to voltage dependency studies at a substation on Vancouver Island.The tests showed a significant reduction on both load (kW) and reactive power (kVAR.) [5] With the California Energy Crisis in 2000-01 interest in CVR as a long term conservation and demand reduction measure gained impetus. In 2002, the author’s company fielded its first automated CVR system projects at Inland Power and Light Company. That project showed significant energy conservation and demandreduction along with significant kvar reduction. In 2004 the Northwest Energy Efficiency Alliance (NEEA) began a major study on the effects of CVR. Known as the NEEA Distribution Efficiency Initiative (DEI) Study, several Pacific Northwest utilities undertook CVR projects utilizing several different methods of accomplishing CVR. That study showed significant energy conservation available byimplementing CVR. Additionally it showed very significant kVAR reduction when CVR is implemented. The final report was issued in December, 2007 [6]. In 2005 Hydro Quebec implemented a CVR pilot project to study the effect of controlled voltage reduction [7]. In 2009 the NWPCC identified over 400 average MW of conservation available using CVR or voltage optimization in its “6th Northwest Power Plan”[8]. With the advent of “smart grid” initiatives the term Volt/VAR optimization (VVO) has come into common use. VVO is the operation of a distribution system with automatic coordinated operation of voltage regulation devices and switched capacitor banks with the goal of minimizing lagging kVAR and controlling distribution voltage levels to some “optimum” point to reach a utilities optimal goal. Thegoal can vary from utility to utility and can be to reduce peak demand, implement CVR, minimize distribution system losses or even in some cases to in-

1.

Conservation Voltage Regulation

Conservation Voltage Regulation (CVR) sometimes called Conservation Voltage Reduction is the long term practice of controlling distribution voltage levels in the lower range of American NationalStandards Institute (ANSI) standard C84.1 – 1995 “Electrical Power Systems and Equipment – Voltage Ratings” or Canadian Standards Association (CSA) standard CAN3-C235-83 “Preferred Voltage Levels for AC Systems, 0 to 50 000V” acceptable levels in order to reduce demand and energy consumption.

1.1

CVR History

In 1980s electric utilities began studying the effect of voltage reduction on energyusage on distribution feeders. In 1981 EPRI commissioned the University of Texas at Arlington to test and study the effects of reduced voltage on the efficiency of important power system loads [1]. That study included such utilization devices as television sets, microwave ovens, motors, heat pumps, air conditioners, distribution transformers, resistance heating devices as well as others. Also in1982 the Environmental Defense Fund (EDF) published an article discussing the efficacy of CVR as an energy conservation method [2]. In 1985 the Northwest Power Planning Council (now the Northwest Power and Conservation Council) (NWPCC) mentioned CVR and called for assessment of loss reduction through reduced voltage. In 1987 Bonneville Power Administration (BPA) commissioned Pacific NorthwestNational Laboratory (PNNL) to assess CVR applicable in the BPA service area0. The assessment concluded that CVR was an effective energy conservation measure and that that potential conservation available in the BPA service territory was up to 270 average Mw or 2.37x106 MWh/year[3]. In 1988-90 Snohomish PUD conducted a pilot study of CVR on 12 distribution feeders. The results of the study confirmed...