An islanded microgrid energy management controller validated by using hardware-in-the-loop emulators

• Published in: International journal of electrical power & energy systems Vol. 106; pp. 346 - 357
• Main Authors: Petreus, D., Etz, R., Patarau, T., Cirstea, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2019
• Subjects: Cycle charge control; Microgrid; Power management; Renewable energies; Two level control; Two level control; Cycle charge control; Renewable energies; Microgrid; Power management
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2018.10.020

•A microgrid emulator which includes different energy sources is proposed.•The emulator can be used to test different management algorithms.•The prime movers of the thermal generators are emulated by induction machines.•An original model of the microgrid is developed and simulated in PSIM.•Experimental laboratory-level hybrid renewable energy microgrids setup is implemented. A novel microgrid emulator used to test multiple microgrid configurations and energy management control strategies is presented. The system includes Hardware-In-the-Loop (HIL) emulators for geothermal and biogas energy sources. It also includes actual photovoltaic energy together with a lead acid battery bank for storage and it is controlled by a two level control system. The control system consists of a primary level voltage-reactive power and frequency-active power and a secondary level energy management algorithm based on the balance between the power produced by the renewable energy generators, state of charge of the battery bank and the loads. The energy management control strategy is based on cycle-charging the batteries at a reference value in order to efficiently use the available resources. The primary energy source is considered the geothermal energy, while the most cost effective one is the photovoltaic energy. A buffer zone is kept in the battery bank in order to store as much energy produced by the photovoltaic system as possible. The presented microgrid, used for testing the energy management strategies, employs emulators for the geothermal and biogas generators; however, the results are relevant and can be scaled for a real-life microgrid.