Frequency stability in electricity networks is essential to the maintenance of supply quality and security. This paper investigates whether a degree of built-in frequency stability could be provided by incorporating dynamic demand control into certain consumer appliances. Such devices would monitor system frequency (a universally available indicator of supply-demand imbalance) and switch the appliance on or off accordingly, striking a compromise between the needs of the appliance and the grid. A simplified computer model of a power grid was created incorporating aggregate generator inertia, governor action and load-frequency dependence plus refrigerators with dynamic demand controllers. Simulation modelling studies were carried out to investigate the system's response to a sudden loss of generation, and to fluctuating wind power. The studies indicated a significant delay in frequency-fall and a reduced dependence on rapidly deployable backup generation.Index Terms-Dynamic demand, dynamic demand control, demand-side management, frequency control, integration of renewable power generation, intelligent load, power system stability, refrigerators.

No abstract

The Pacific NorthwestElectric Pcwer Planning and ConservatlonAct, signed Into law December 5, 1980, mandated reglonwldeenergy conservationpractices. Under the act, BPA must identlfyand Implementcost-effectlve electric energy options and programs for the Pacific Northwest, The ResldentlalTechnology Section In the D1vislonof ResourceManagementsupports currentresidentlal energy conservationprograms and deslgns and conducts various research and developmentprojects,of which thls project Is one. Laboratorytest proceduresused by the Japanese had shown their refrigerators to be about 50 percent more efficientthan Amerlcan-maderefrigerators. A previous BPA study tested 12 Japanese refrigeratorsaccordingto the U.S..DO_ laboratoryprocedure. Nhen tested to the DOE procedure,Japanese refrlgeratorsused about 43 percent more energy than when tested by the Japanese procedure. This study compared in-homeenergy use of 12 Japanese refrigeratorsidentical to those In the laboratorytest to both the Japanese and U.S. DOE laboratory tests. Pro__i_ec____roa_b To test In-homeenergy use, the 12 Japaneserefrigeratorswere placed In the homes of BPA employees In the Portland/Vancouver area and used as the prlmary refrigeratorfor 18 months. Data was recordedmanually by homeownersand included: cumulativeenergy use cumulativedoor openings winter thermostatsetting number of occupants at the beglnnlngof the test any special applicableevents All collecteddata was entered into a computer spreadsheetand analyzed to produce this report.

Under the act, BPA must identlfy and implementcost-effectiveelectric energy options and programsfor the Pacific Northwest. The ResidentialTechnology Section In the Dlvision of ResourceManagementsupports current residential energy conservationprograms and deslgnsand conducts various research and developmentprojects,of which thls projecC Is one.Laboratorytest proceduresused by the Japanese had shown their refrigerators to be about 50 percent more efficientthan American-maderefrigerators. A previous BPA study tested 12 Japanese refrlgeratorsaccordingto the U.S. DOE laboratoryprocedure. When tested to the DOE procedure,Japanese refrigeratorsused about 43 percent more energy than when tested by the Japanese procedure.This study compared in-homeenergy use of 12 Japanese refrlgeratorsidentical to those In the laboratorytest to both the Japanese and U.S. DOE laboratory tests. P_e.i_ecLAp_p_zo__cbTo test In-homeenergy use, the 12 Japanese refrigeratorswere placed In the homes of BPA employees In the Portland/Vancouver area and used as the primary refrigeratorfor 18 months. Data was recordedmanually by homeownersand included: cumulatlveenergy use cumulativedoor openings winter thermostatsetting number of occupants at the beglnnlngof the test any special applicableevents All collecteddata was entered Into a computer spreadsheetand analyzed to produce this report.