Decentralized robust energy and reserve Co-optimization for multiple integrated electricity and heating systems

Chapter 7 - Decentralized robust energy and reserve co-optimization for multiple integrated electricity and heating systems

In traditional integrated electricity and district heating systems, the inflexible operation of combined heat and power units leads to a large amount of wind power curtailments during winter. The thermal inertia of aggregated buildings can provide additional operational flexibility to promote wind power accommodation. In this study, a day‐ahead scheduling model for integrated electricity and district heating system considering the thermal inertia of buildings is proposed. In this work, the operation model of the district heating network under constant mass flow and variable temperature operation strategy is presented, and the aggregated model of buildings based on the detailed thermal model of buildings is established. Then, the scheduling framework is analysed and the day‐ahead scheduling model is formulated as quadratic programming problem to minimise the operation cost of integrated electricity and district heating system. The validity of the proposed model is verified by the case studies performed on a 6‐bus power system with a 6‐node heating system and IEEE 39‐bus electricity system with a 16‐node heating system. The results demonstrate that the thermal inertia of buildings can provide additional operational flexibility and effectively help reduce wind power curtailment and operation costs.

Interconnection and coupling between electric power, heating and natural gas systems are becoming closer and closer. From the point of view of coordinated optimization, through the establishment of mathematical model of district electricity and heating system, a coordinated optimization model of district electricity and heating system based on genetic algorithm is constructed in this paper. A typical district electricity and heating system in engineering is modelled and analyzed using the above mentioned model, the average convergence characteristics and optimization effect are studied. Through the experimental results, the practicability and validity of the coordinated optimization model of district electricity and heating system based on genetic algorithm are verified. The research contents of this paper lays the foundation for the operation optimization of district electricity and heating system.

The coupled electricity and heat system (CEHS) is considered one of the most efficient energy utilization schemes for the energy transition to solve energy crises and environmental problems. However, the individual data between the power system (PS) and heat system (HS) probably limit the high share and optimization operation. Moreover, the uncertain renewables and complex coupled network create challenges regarding the operation risk of CEHS. Given that the CEHS may be affiliated with different operation entities, this paper proposes two operation modes to achieve the solution of the optimal risk operation model (OROM), including the distributionally robust chance constraint (DRCC)-based centralized risk operation mode (CROM) and the DRCC-based alternating direction method of multipliers (ADMM) distributed risk operation mode (DROM). By formulating the moment-based ambiguity set estimated from historical data and introducing the operation risk constraints, a tractable reformulation of two-stage DRCC OROM problems is presented under CROM. Moreover, the DRCC-based ADMM distributed algorithm with the guarantee of convergence is developed to optimize the PS and HS independently under DROM considering the operation risk. The two operation modes achieve the minimum amount of information shared between the two systems regarding the underlying distribution. In the numerical case, the approximate OROM solution is obtained between CROM and DROM. The two proposed approaches based on different operation modes outperform the existing methods according to the risk level depicted by different forms of the violation probability and the risk cost compared with Gaussian chance constraint (GCC) under CROM, while the safety coefficient $\epsilon $ is set as 0.25. Then, the impact of the iteration number on the convergence is also discussed with comparison of the classical ADMM under DROM.

Collaborative scheduling and flexibility assessment of integrated electricity and district heating systems utilizing thermal inertia of district heating network and aggregated buildings

Uncertainty-fully-aware coordinated dispatch of integrated electricity and heat system

ABSTRACTThis study investigates how thermal energy storage (TES) influences the cost-optimal investment and operation of electricity and district heating (DH) systems in different scenarios. Greenfield energy system modelling for Year 2050 with a high time resolution shows that sensible TES strategies have a strong impact on the composition and operation of the DH system in all investigated scenarios. The introduction of TES displaces to a significant extent the heat-only boilers in all scenarios and can promote solar heating in small DH networks. The modelling shows that TES also promotes the use of power-to-heat processes and enables combined heat and power plants to increase full-load hours, with simultaneous adaptation to the variable production in the electricity system. A major benefit derived from TES is the ability to respond to rapid variations in the electricity system. Thus, the pit and tank storage systems with higher (dis)charging capacities are preferred over borehole storage.

Adaptive robust energy and reserve co-optimization of integrated electricity and heating system considering wind uncertainty

In order to protect environment and improve utilization efficiency of energy, district electricity and heating system has been well developed with the supportive policy. However, the coupling between electrical system and heating system brings challenges to the existed theories for energy system analysis. Energy network theory is proposed after an in-depth analysis of the nature of energy. The analysis of transfer process of electric energy, pressure energy and heat energy is proposed following rigorous mathematical derivation and analysis. Based on the energy network theory, the commonalities and characteristics of energy subnets are studied. Then, the energy network equations of district electricity and heating system are established. These equations are used for the modeling of a typical district electricity and heating system. A numerical case is analyzed by comparison between theoretical results and actual parameters, showing the validity of the energy network theory.

Chapter 6 - Adaptive robust energy and reserve co-optimization of an integrated electricity and heating system considering wind uncertainty

Experimental evaluation of an integrated demand response program using electric heat boosters to provide multi-system services

Effects of the operation regulation modes of district heating system on an integrated heat and power dispatch system for wind power integration

Day-ahead energy and reserve scheduling under correlated wind power production

Guest Editorial: Situational awareness of integrated energy systems

Coordinated operation of integrated electricity and district heating system (IEDHS) has great potential to enhance the flexibility of the power system to cope with the wind power curtailment. This study proposes an interval optimal scheduling algorithm for IEDHSs, considering the dynamic characteristics of the heating network. The model of the district heating system with dynamic characteristics including transmission delay and heat losses, is established in detail, and the uncertainties of both wind power and electricity and heating loads are described with interval numbers. Then an interval optimal scheduling model of the IEDHS is formulated to minimise the IEDHS operation cost. The impacts of the transmission delay and heat losses of the heating network on the scheduling of the IEDHS are analysed. Case studies are performed on the PJM 5-bus electricity system with a 6-node district heating system and IEEE 39-bus electricity system with a 12-node district heating system to evaluate the effectiveness of the proposed model. The results demonstrate that the dynamic characteristics of the heating network can integrate more wind power and enlarge the width of the cost interval.