Research&Application Of East China Power Grid Dynamic Area Control Error

North American Electric Reliability Council （NERC） proposed ControlPerformance Standards CPS1and CPS2to replace Al and A2standards andDisturbance Control Standard (DCS) to B1and B2standards for the betterevaluation of the frequency control behavior of each control area in aninterconnected power system in1997. Since1998, NERC requested the controlarea to meet the standards that CPS1greater than100%and CPS2greater than90%. The purpose of the Disturbance Control Standard (DCS) is to ensure thebalancing authority is able to utilize its contingency reserve to balance resourcesand demand and return interconnection frequency within defined limitsfollowing a reportable disturbance.Both CPS and DCS are based on Area Control Error(ACE) proposed byNERC. These standards are intended to improve the interconnection frequencyassessment and control system, most of whose calculation methods are proposedby NERC and to encourage each control area endeavor to improve its ownfrequency regulation ability, which thus enhances the interconnection frequencyquality and its anti-disturbance ability. The purpose of dynamic area controlerror is to reinforce interconnection frequency regulation ability, which must berealized by modifying ACE calculation method proposed by NERC. Thedrawbacks of Area Control Error(ACE) is analyzed. East China Power Gridshows typical huge receiving end power grid characteristics with its growth.Obviously, manual modification of scheduling plan slows down the frequencyregulation speed in the case of large power supply loss. In order to speed upfrequency regulation, East China Grid is determined to develop dynamic areacontrol error to exert contingency reserve of each control area to help enhance frequency regulation according to its distinctive characteristics. Dynamic AreaControl Error(DACE) is introduced by its calculation method and physicalinterpretation. Dynamic ACE calculation method and its technical proposal isdeveloped by analyzing the specialties of power failure caused by DC poweroutside control area, large capacity generator which is shared by all controlareas, large capacity generator owned by certain control area, multiple fault ofprevious cases and special frequency mode, some control area quit dynamicACE calculation for instance. These corresponding algorithms and techniquesare tested in the simulation mode followed by actual exercise in the EMSsystem to verify their validity and reliability. Meanwhile, constant revisions aremade to parameters of DACE to meet the needs of real-time power griddispatching system, like trigger threshold of frequency, frequency change rate,power loss threshold and power loss limit and etc.CPS and DCS assessments embedded with DACE frame an optimalinterconnection frequency assessment and control system. which provide apossible approach for the frequncy control for other interconnected powersystem on the earth.