Preventive Power Rescheduling for Electric Frequency Enhancement in Integrated Energy Systems

Abstract

Under the occurrence of a critical disturbance that produces a large load-generation imbalance in an electric power system, the primary regulation control may not be sufficient to bound the steady-state error of the frequency deviation within its normal operating range. This also has an effect on the steady-state operational interdependency of multi-energy systems. To overcome this lack of controllability, this paper proposes a new, practical preventive control action for assessing the steady-state interdependency between gas and electricity infrastructures with a feasible control of the frequency deviation. The proposed approach consists of the solution of two mutually connected subproblems: one related to the gas and power flow problem and the other associated with the economic dispatch problem. These two problems are sequentially solved until a feasible equilibrium point is obtained in which the multi-energy system operates with a value of the electrical frequency within limits. The effectiveness of the proposed control action and the validity of the theoretical concepts on which the proposed approach is based are demonstrated numerically in an integrated multi-energy system consisting of a 15-node gas network and 3-bus electrical system.