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ECONOMIC MPC-BASED DESIGN AND OPERATION OF GRID SCALE ENERGY STORAGE SYSTEMS
Title
ECONOMIC MPC-BASED DESIGN AND OPERATION OF GRID SCALE ENERGY STORAGE SYSTEMS
Creator
Adeodu, Oluwasanmi
Date
2019
Description
It is generally recognized that a higher penetration of renewable power on the electric grid, along with the attendant environmental benefits,...
Show moreIt is generally recognized that a higher penetration of renewable power on the electric grid, along with the attendant environmental benefits, is limited by its inherent high variability and intermittency. An approach to alleviating this issue is to install grid scale energy storage as buffer. However, the economic viability of such an endeavor is dependent on the optimal sizing and placement (OSP) of storage units, which in turn requires the specification of an appropriate storage management policy. While stochastic programming with recourse is recognized as the standard approach to stage-wise optimal decision-making under uncertainty, Economic Model Predictive Control (EMPC) is put forward as a deterministic simplification of the former and demonstrated to be a viable economic dispatch strategy for networks with a high proportion of renewable energy and storage. Then, a numerical, EMPC-based gradient search strategy is proposed to address the OSP problem. Since both the operating policy and OSP questions are invariably massive optimization problems in real systems, strong emphasis is laid on computational tractability. Therefore, the analytical nature of a surrogate stochastic control policy, Economic Linear Optimal Control (ELOC), is exploited to develop innovative modifications to both algorithms. The end products are (1), an Approximate Infinite Horizon EMPC (AIH-EMPC) strategy, a relatively low computational cost variant of EMPC and (2), a hybrid EMPC-ELOC OSP strategy that essentially sidesteps the inherent combinatorial complexity of the unit location problem.
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PROCESS DESIGN FOR SMART GRID COORDINATED IGCC POWER PLANT
Title
PROCESS DESIGN FOR SMART GRID COORDINATED IGCC POWER PLANT
Creator
Garcia Fracaro, Sofia Belen
Date
2019
Description
The current scientific consensus is that changes in greenhouse gas emissions will have wide-ranging effects on the natural environment as well...
Show moreThe current scientific consensus is that changes in greenhouse gas emissions will have wide-ranging effects on the natural environment as well as on human society and world economies. Cutting green house gas emissions could be achieved by switching the majority of power production to renewable sources, like wind and solar. However, the intermittent nature of renewable sources will require special attention when integrating into the electric power system. The notion of a smart grid is to introduce new dispatch capable sources as well as provide mechanisms for consumers to be responsive to power availability. One way a smart grid communicates its objectives is through the price of electricity. Economic Model Predictive Control (EMPC) can utilize forecasts of electricity prices to determine operating policies for dispatch capable generators and flexible consumers. While EMPC in the context of variable electricity prices can reduce costs (or increase the revenue), operational flexibility will usually require equipment upgrade, and add to the capital cost of the system. In this thesis an Integrated Gasification Combined Cycle (IGCC) will be used to illustrate potential dispatch capabilities, the benefits of EMPC based operation, and the challenges associated with process design in the context of smart grid coordinated operation. First it is assumed that dispatch enabling equipment is available. While EMPC can provide an increase in the revenue during plant operation, it is not amenable to the equipment design problem. While the method of ELOC can be used for integrated process design and control, we must first show that ELOC performs similar to EMPC and that it can serve as a surrogate. Finally, the ELOC based equipment design problem is formulated, which optimizes with respect to operating as well as capital costs.
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