A joint approach for strategic bidding of a microgrid in energy and spinning reserve markets

n the electricity market, short-term operation is organized in day-ahead and real-time stages. The two stages that are performed in different time intervals have reciprocal effects on each other. The paper shows the strategy of a microgrid that participates to both day-ahead energy and spinning reserve market. It is supposed that microgrid is managed by a prosumer, a decision maker who manages distributed energy sources, storage units, Information and Communication Technologies (ICT) elements, and loads involved in the grid. The strategy is formulated considering that all decisions about the amount of power to sell in both markets and the price links to the offer, must be taken contextually and at the same time, that is through a joint approach. In order to develop an optimal bidding strategy for energy markets, prosumer implements a nonlinear mixed integer optimization model: in this way, by aggregating and coordinating various distributed energy sources, including renewable energy sources, micro-turbines–electricity power plants, combined heat and power plants, heat production plants (boilers), and energy storage systems, prosumer is able to optimally allocate the capacities for energy and spinning reserve market and maximize its revenues from different markets. Moreover, it is considered that both generators and loads can take part in the reserve market. The demand participation happens through both shiftable and curtailable loads. Case studies based on microgrid with various distributed energy sources demonstrate the market behavior of the prosumer using the proposed bidding model

Optimal energy management in virtual power plants applying mixed integer linear programming

Orientadores: Luiz Carlos Pereira da Silva, Marcos Julio Rider FloresDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: O presente trabalho apresenta os conceitos, os desafios e a operação otimizada das Plantas Virtuais de Geração (VPP ¿ Virtual Power Plants), um conjunto de diferentes recursos energéticos distribuídos, como unidades de geração distribuída principalmente de origem renovável, sistemas de armazenamento de energia e cargas controláveis operando como uma grande e única usina geradora, analisada sob a óptica da concessionária. Este modelo de agregação dos recursos disponíveis no sistema de distribuição oferece benefícios técnicos e comerciais aos detentores das unidades de geração, aos consumidores de energia elétrica, e à concessionária responsável pela gestão da VPP. Suas metas são atingidas através do sistema de gerenciamento de energia, responsável por definir o estado de operação dos ativos e por gerenciar a operação da rede. Neste trabalho, propõe-se um sistema de gestão de energia, baseado num modelo de programação linear inteira mista (PLIM), capaz de controlar o carregamento de baterias, a operação de cargas controláveis e a gestão do carregamento de veículos elétricos em microrredes para comprovar a confiabilidade e a flexibilidade oferecidas pela VPP. O trabalho aborda os benefícios e desafios para a construção deste sofisticado sistema de distribuição de energia que já é realidade em alguns países, apresentando os principais componentes para a integração dos recursos, como sistemas de medição, gerenciamento pelo lado da demanda e os conceitos aplicados à gestão de energia, tamanha a necessidade de gestão inteligente e eficiente do fornecimento de energia. Uma simulação inicial foi executada no software GridLAB-D para extração dos valores de demanda e de geração. Em seguida, executa-se a etapa de otimização utilizando o modelo de PLIM proposto escrito em AMPL (A Mathematical Programming Language), através do solver comercial CPLEX para um período de 24 horas dividido em intervalos de 15 minutos. As simulações são feitas para atender a função objetivo, respeitando as restrições operacionais. São consideradas metas como redução de perdas ôhmicas, redução de consumo de energia da subestação e otimização do carregamento de veículos elétricos. Os resultados demonstram que as VPPs são uma solução eficiente para gerir de forma inteligente e dinâmica a distribuição de energia, tendo a operação flexível e confiável como valores fundamentais para a operaçãoAbstract: This dissertation presents the concepts, challenges and optimal operation of Virtual Power Plants (VPPs), a set of different distributed energy resources, such as distributed generation units specially based on renewable sources, energy storage systems and controllable loads operating like a unique large power plant, analyzed under the perspective of a power utility. This aggregation model for available resources on the distribution system offers technical and commercial benefits to their owners, to the customers and to the power utilities that drives the VPP. Its targets are achieved throughout the Energy Management System, responsible for defining the operating state of assets and for managing the operation of the electric grid. On this dissertation it is proposed an energy management system, based on a Mixed-Integer Linear Programming (MILP) Model, responsible for controlling batteries charging, controllable loads operation and electric vehicles charging on microgrids to prove the reliability and flexibility offered by VPPs. The work addresses the benefits and challenges to assembly this sophisticated energy distribution system that has already been implemented in some countries, presenting the main components for resources integration, such as metering systems, demand side management and concepts applied to energy management, given the necessity of an intelligent and efficient management system for power delivery. An initial simulation was performed on the software GridLAB-D to extract the demand and generation levels. Then, the optimization was performed using a mixed integer linear programing model written in AMPL (A Mathematical Programming Language) and solved using the commercial solver CPLEX for 24 hours, divided into 96 timestamps of 15 minutes each. The simulation was performed to meet the objective function, respecting the operational constraints. Ohmic losses reduction, substation energy consumption and optimal electrical vehicle charging are considered as its goals. The results demonstrate that Virtual Power Plants are an efficient solution to intelligently and dynamically manage the energy distribution, relying on flexibility and reliability as core valuesMestradoEnergia EletricaMestre em Engenharia Elétric