Distributionally Robust Negative-Emission Optimal Energy Scheduling for Off-Grid Integrated Electricity-Heat Microgrid

Abstract

This paper proposes a distributionally robust chance-constrained (DRCC) negative-emission optimal energy scheduling scheme for the off-grid integrated electricity-heat microgrid (IEHM). A negative-emission operating strategy is designed to regulate the electric power, thermal power, and carbon emission of the off-grid IEHM under uncertainty. The post-combustion carbon capture system (PCCS) and direct air capture (DAC) modeling consider both electric and thermal energy consumption. Besides, the duration of DAC process flow is considered in its model. In the DRCC energy scheduling model for the off-grid IEHM, the negative emission is achieved by scheduling PCCS and DAC, and the negative emission constraint is included considering the uncertainty of carbon emission. The uncertain forecasting errors of wind power are balanced by coordinating the combined heat and power unit and battery storage. DRCC approach under the moment-based ambiguity set is employed to tackle both uncertainties. The DRCC energy scheduling model is reformulated as a tractable mixed-integer second-order cone programming. Evaluation indices are defined from three aspects, i.e., carbon emission, economy, and reserve capacity, to assess the overall performance of the DRCC energy scheduling scheme for the off-grid IEHM. Case studies were carried out on two test systems to validate the effectiveness of the proposed method. Simulation results demonstrate that the off-grid IEHM can achieve negative emission operation while minimizing the energy cost under wind power and carbon emission uncertainty.