Distributionally robust unit commitment of integrated electricity and heat system under bi-directional variable mass flow

Abstract

This paper proposes a distributionally robust unit commitment of integrated electricity and heat system, in which the district heating systems are operated under variable flow and variable temperature (VFVT) with bi-directional mass flow considered rather than the commonly used constant flow and variable temperature (CFVT) control method to increase the flexibility capacity for renewable energy accommodation, and the distributionally robust optimization scheme adopted can additionally help increase the operation flexibility of system under high penetration of renewable energy. Piecewise linear method is adopted to convert the mixed integer nonlinear problem into its mixed integer linear counterpart, and tractable alternating optimization procedure is adopted to solve the problem in a decentralized scheme. Case studies conducted on a small scale system and a large scale system respectively demonstrates the effectiveness and the applicability of this method.