Microgrid Energy Management during High-Stress Operation

We consider the energy management of an isolated microgrid powered by photovoltaics (PV) and fuel-based generation with limited energy storage. The grid may need to shed load or energy when operating in stressed conditions, such as when nighttime electrical loads occur or if there is little energy s...

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Main Authors: Thomas Price, Gordon Parker, Gail Vaucher, Robert Jane, Morris Berman
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/15/18/6589
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author Thomas Price
Gordon Parker
Gail Vaucher
Robert Jane
Morris Berman
author_facet Thomas Price
Gordon Parker
Gail Vaucher
Robert Jane
Morris Berman
author_sort Thomas Price
collection DOAJ
description We consider the energy management of an isolated microgrid powered by photovoltaics (PV) and fuel-based generation with limited energy storage. The grid may need to shed load or energy when operating in stressed conditions, such as when nighttime electrical loads occur or if there is little energy storage capacity. An energy management system (EMS) can prevent load and energy shedding during stress conditions while minimizing fuel consumption. This is important when the loads are high priority and fuel is in short supply, such as in disaster relief and military applications. One example is a low-power, provisional microgrid deployed temporarily to service communication loads immediately after an earthquake. Due to changing circumstances, the power grid may be required to service additional loads for which its storage and generation were not originally designed. An EMS that uses forecasted load and generation has the potential to extend the operation, enhancing the relief objectives. Our focus was to explore how using forecasted loads and PV generation impacts energy management strategy performance. A microgrid EMS was developed exploiting PV and load forecasts to meet electrical loads, harvest all available PV, manage storage and minimize fuel consumption. It used a Model Predictive Control (MPC) approach with the instantaneous grid storage state as feedback to compensate for forecasting errors. Four scenarios were simulated, spanning a stressed and unstressed grid operation. The MPC approach was compared to a rule-based EMS that did not use load and PV forecasting. Both algorithms updated the generator’s power setpoint every 15 min, where the grid’s storage was used as a slack asset. While both methods had similar performance under unstressed conditions, the MPC EMS showed gains in storage management and load shedding when the microgrid was stressed. When the initial storage was low, the rule-based EMS could not meet the load requirements and shed 16% of the day’s electrical load. In contrast, the forecast-based EMS managed the load requirements for this scenario without shedding load or energy. The EMS sensitivity to forecast error was also examined by introducing load and PV generation uncertainty. The MPC strategy successfully corrected the errors through storage management. Since weather affects both PV energy generation and many types of electrical loads, this work suggests that weather forecasting advances can improve remote microgrid performance in terms of fuel consumption, load satisfaction, and energy storage requirements.
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spelling doaj.art-c34dc21ac100445e8bfd4897ad46f3292023-11-23T16:02:20ZengMDPI AGEnergies1996-10732022-09-011518658910.3390/en15186589Microgrid Energy Management during High-Stress OperationThomas Price0Gordon Parker1Gail Vaucher2Robert Jane3Morris Berman4Mechanical Engineering-Engineering Mechanics Department, Michigan Technological University, Houghton, MI 49931, USAMechanical Engineering-Engineering Mechanics Department, Michigan Technological University, Houghton, MI 49931, USAUS Army Research Laboratory, US Army Combat Capabilities Development Command, US Army Futures Command, White Sands Missile Range, NM 88002, USAUS Army Research Laboratory, US Army Combat Capabilities Development Command, US Army Futures Command, Adelphi, MD 20783, USAUS Army Research Laboratory, US Army Combat Capabilities Development Command, US Army Futures Command, Adelphi, MD 20783, USAWe consider the energy management of an isolated microgrid powered by photovoltaics (PV) and fuel-based generation with limited energy storage. The grid may need to shed load or energy when operating in stressed conditions, such as when nighttime electrical loads occur or if there is little energy storage capacity. An energy management system (EMS) can prevent load and energy shedding during stress conditions while minimizing fuel consumption. This is important when the loads are high priority and fuel is in short supply, such as in disaster relief and military applications. One example is a low-power, provisional microgrid deployed temporarily to service communication loads immediately after an earthquake. Due to changing circumstances, the power grid may be required to service additional loads for which its storage and generation were not originally designed. An EMS that uses forecasted load and generation has the potential to extend the operation, enhancing the relief objectives. Our focus was to explore how using forecasted loads and PV generation impacts energy management strategy performance. A microgrid EMS was developed exploiting PV and load forecasts to meet electrical loads, harvest all available PV, manage storage and minimize fuel consumption. It used a Model Predictive Control (MPC) approach with the instantaneous grid storage state as feedback to compensate for forecasting errors. Four scenarios were simulated, spanning a stressed and unstressed grid operation. The MPC approach was compared to a rule-based EMS that did not use load and PV forecasting. Both algorithms updated the generator’s power setpoint every 15 min, where the grid’s storage was used as a slack asset. While both methods had similar performance under unstressed conditions, the MPC EMS showed gains in storage management and load shedding when the microgrid was stressed. When the initial storage was low, the rule-based EMS could not meet the load requirements and shed 16% of the day’s electrical load. In contrast, the forecast-based EMS managed the load requirements for this scenario without shedding load or energy. The EMS sensitivity to forecast error was also examined by introducing load and PV generation uncertainty. The MPC strategy successfully corrected the errors through storage management. Since weather affects both PV energy generation and many types of electrical loads, this work suggests that weather forecasting advances can improve remote microgrid performance in terms of fuel consumption, load satisfaction, and energy storage requirements.https://www.mdpi.com/1996-1073/15/18/6589clear skyelectrical load forecastfuel consumptionenergy management systemenergy storage requirementsmicrogrid
spellingShingle Thomas Price
Gordon Parker
Gail Vaucher
Robert Jane
Morris Berman
Microgrid Energy Management during High-Stress Operation
Energies
clear sky
electrical load forecast
fuel consumption
energy management system
energy storage requirements
microgrid
title Microgrid Energy Management during High-Stress Operation
title_full Microgrid Energy Management during High-Stress Operation
title_fullStr Microgrid Energy Management during High-Stress Operation
title_full_unstemmed Microgrid Energy Management during High-Stress Operation
title_short Microgrid Energy Management during High-Stress Operation
title_sort microgrid energy management during high stress operation
topic clear sky
electrical load forecast
fuel consumption
energy management system
energy storage requirements
microgrid
url https://www.mdpi.com/1996-1073/15/18/6589
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AT gailvaucher microgridenergymanagementduringhighstressoperation
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AT morrisberman microgridenergymanagementduringhighstressoperation