Optimization of smart microgrid considering domestic flexible loads

Abstract

The generated power is adjusted on the base of the predicted energy demand for near future, in the existing power systems. In other words, the generated energy follows load profile to meet the energy demand. There is no control over the loads except load shedding which may happen during the fault incidents or peak energy demand. Integration of renewable energy sources into the grid, has introduced further complexity in the above mentioned strategy of following the load curve. Main renewable energies like wind or solar power are not accurately predictable. The uncertain amount of the generated energy necessitate the increase in the generation and storage capacity of the energy by constructing bigger or more number of power plants and energy storage facilities. This will increase cost, pollution, and number of turning off/on of the power plants. Identification and appropriate control of flexible loads can be employed to balance energy generation and demand. In other words contrary to the traditional methods, the proposed method will enable the system to meet the demand not only by changing the generated energy but also by controlling the loads when necessary. Also utilizing flexible loads will significantly reduce energy loss of the storage equipments. Instead of storing energy to be used later, flexible load can consume that energy whenever is needed. In this paper, we consider smart microgrid consist of wind turbines, solar panels, fuel cells, electrolyzers, and smart appliance. In this study, we consider washing machines as flexible loads and we want to manage and control these loads to reduce sizes of generation units, buying and selling energy from distribution grid and total cost of smart microgrid. This study is performed for Ekbatan residential complex Tehran, Iran.