System of Systems Based Decision-Making for Power Systems Operation

A modern power system is composed of many individual entities collaborating with each other to operate the entire system in a secure and economic manner. These entities may have different owners and operators with their own operating rules and policies, and it complicates the decision-making process in the system. In this work, a system of systems (SoS) engineering framework is presented for optimally operating the modern power systems. The proposed SoS framework defines each entity as an independent system with its own regulations, and the communication and process of information exchange between the systems are discussed. Since the independent systems are working in an interconnected system, the operating condition of one may impact the operating condition of others. According to the independent systems’ characteristics and connection between them, an optimization problem is formulated for each independent system. In order to solve the optimization problem of each system and to optimally operate the entire SoS-based power system, a decentralized decision-making algorithm is developed. Using this algorithm, only a limited amount of information is exchanged among different systems, and the operators of independent systems do not need to exchange all the information, which may be commercially sensitive, with each other. In addition, applying chance-constrained stochastic programming, the impact of uncertain variables, such as renewable generation and load demands, is modeled in the proposed SoS-based decision-making algorithm. The proposed SoS-based decision-making algorithm is applied to find the optimal and secure operating point of an active distribution grid (ADG). This SoS framework models the distribution company (DISCO) and microgrids (MGs) as independent systems having the right to work based on their own operating rules and policies, and it coordinates the DISCO and MGs operating condition. The proposed decision-making algorithm is also performed to solve the security-constrained unit commitment incorporating distributed generations (DGs) located in ADGs. The independent system operator (ISO) and DISCO are modeled as self-governing systems, and competition and collaboration between them are explained according to the SoS framework

Multi-stage stochastic optimal operation of energy-efficient building with combined heat and power system

Due to the integration of volatile renewable energy and random energy consumption in the building grid, uncertainties have become a big concern for the operation of energy-efficient buildings. To minimize energy usage expenses under uncertainty, it is necessary to determine the optimal power production for a building from various energy sources, including the electric grid, battery, and combined heat and power with a boiler unit. This article presents a multi-stage mixed-integer stochastic programming model for optimal operation of energy-efficient building systems considering controllable electric and thermal loads. Taking into account the randomness of non-controllable electric and thermal loads, as well as solar power generations through the multi-stage scenario tree, the operation of energy-efficient buildings will be more robust against changes in uncertain variables. With information of uncertainties updated hourly, the rolling scheduling method is introduced to determine an adaptive power output of electric grid, charging/discharging status of the battery, and operation of combined heat and power with a boiler unit. The simulation results offer a set of adaptive decision solutions within the scheduling horizon. © 2014 Copyright Taylor and Francis Group, LLC

Optimal operation of active distribution grids: A system of systems framework

Active distribution grid is composed of autonomous systems which should collaborate with each other in order to operate the entire distribution grid in a secure and economic manner. This paper presents a system of systems (SoS) framework for optimally operating active distribution grids. The proposed SoS framework defines both distribution company (DISCO) and microgrids (MGs) as independent systems, and identifies the process of information exchange among them. As the DISCO and MGs are physically connected together, the operating condition of one might impact the operating point of other systems. The proposed mathematical model uses a decentralized optimization problem aimed at maximizing the benefit of each independent system. A hierarchical optimization algorithm is presented to coordinate the independent systems and to find the optimal operating point of the SoS-based active distribution grid. The numerical results show the effectiveness of the proposed SoS framework and solution methodology. © 2010-2012 IEEE