A review of optimal operation of microgrids

The term microgrid refers to small-scale power grid that can operate autonomously or in concurrence with the area’s main electrical grid. The intermittent characteristic of DGs which defies the power quality and voltage manifests the requirement for new planning and operation approaches for microgrids. Consequently, conventional optimization methods in new power systems have been critically biased all through the previous decade. One of the main technological and inexpensive tools in this regard is the optimal generation scheduling of microgrid. As a primary optimization tool in the planning and operation fields, optimal operation has an undeniable part in the power system. This paper reviews and evaluates the optimal operation approaches mostly related to microgrids. In this work, the foremost optimal generation scheduling approaches are compared in terms of their objective functions, techniques and constraints. To conclude, a few fundamental challenges occurring from the latest optimal generation scheduling techniques in microgrids are addressed

Day-Ahead Network-Constrained Scheduling of CHP and Wind Based Energy Systems Integrated with Hydrogen Storage Technology

The integration of renewable energy sources is vastly increased in recent decades considering environmental concerns and lack of fossil fuels. Such integration has appeared novel challenges in electrical energy systems according to their uncertain nature. The hydrogen energy storage (HES) system plays a significant role is power systems by converting extra wind power to the hydrogen using power to hydrogen (P2H) technology. In addition, the emerging technologies such as combined heat and power (CHP) units are effective in increasing the efficiency of power systems. This work presents a day-ahead scheduling scheme for CHP-HES based electrical energy networks with high integration of wind power sources. The effectiveness of the presented model is investigated by implementation on the IEEE 6-bus system. The impact of heat load increment has been studied on scheduling of generation plants, wind power dispatch and operation cost of the system. The simulation results prove that operation cost of the system and wind power curtailment have been decreased using the HES technology

Systematic categorization of optimization strategies for virtual power plants

Due to the rapid growth in power consumption of domestic and industrial appliances, distributed energy generation units face difficulties in supplying power efficiently. The integration of distributed energy resources (DERs) and energy storage systems (ESSs) provides a solution to these problems using appropriate management schemes to achieve optimal operation. Furthermore, to lessen the uncertainties of distributed energy management systems, a decentralized energy management system named virtual power plant (VPP) plays a significant role. This paper presents a comprehensive review of 65 existing different VPP optimization models, techniques, and algorithms based on their system configuration, parameters, and control schemes. Moreover, the paper categorizes the discussed optimization techniques into seven different types, namely conventional technique, offering model, intelligent technique, price-based unit commitment (PBUC) model, optimal bidding, stochastic technique, and linear programming, to underline the commercial and technical efficacy of VPP at day-ahead scheduling at the electricity market. The uncertainties of market prices, load demand, and power distribution in the VPP system are mentioned and analyzed to maximize the system profits with minimum cost. The outcome of the systematic categorization is believed to be a base for future endeavors in the field of VPP development