An analytical characterisation of cold-load pickup oscillations in thermostatically controlled loads

PERFUMO, CRISTIAN; JULIO BRASLAVSKY,; JOHN WARD; ERNESTO KOFMAN

Perth

Conferencia; 3rd Australian Control Conference (AUCC); 2013

IEEE

Large groups of thermostatically controlled loadscan be controlled to achieve the necessary balance betweengeneration and demand in power networks. When a significantportion of a population of thermostatically controlled loads isforced to change their on-off state simultaneously, the aggregatepower demand of such population presents large, underdampedoscillations, a well-known phenomenon referred to by powerutilities as ?cold-load pickup?. Characterising these oscillationsand, in general, the aggregate dynamics of the populationfacilitates mathematical analysis and control design. In thispaper we present a stochastic model for the power responseand derive simple expressions for the period and envelope ofthe oscillations.