Modeling and Real-Time Scheduling of DC Platform Supply Vessel for Fuel Efficient Operation

DC marine architecture integrated with variable speed diesel generators (DGs) has garnered the attention of the researchers primarily because of its ability to deliver fuel efficient operation. This paper aims in modeling and to autonomously perform real-time load scheduling of dc platform supply vessel (PSV) with an objective to minimize specific fuel oil consumption (SFOC) for better fuel efficiency. Focus has been on the modeling of various components and control routines, which are envisaged to be an integral part of dc PSVs. Integration with photovoltaic-based energy storage system (ESS) has been considered as an option to cater for the short time load transients. In this context, this paper proposes a real-time transient simulation scheme, which comprises of optimized generation scheduling of generators and ESS using dc optimal power flow algorithm. This framework considers real dynamics of dc PSV during various marine operations with possible contingency scenarios, such as outage of generation systems, abrupt load changes, and unavailability of ESS. The proposed modeling and control routines with real-time transient simulation scheme have been validated utilizing the real-time marine simulation platform. The results indicate that the coordinated treatment of renewable based ESS with DGs operating with optimized speed yields better fuel savings. This has been observed in improved SFOC operating trajectory for critical marine missions. Furthermore, SFOC minimization at multiple suboptimal points with its treatment in the real-time marine system is also highlighted

Scheduling of battery energy storages in the joint energy and reserve markets based on the static frequency of power system

By using the battery energy storage (BES) as a fast, reliable, and controllable resource, the system operator can compensate for power mismatches via changing the generation and consumption in discharging and charging modes. However, BES could decrease the inertia of the grid and endanger the security of the system. Therefore, system operators require a scheduling model that takes into account both security and economic issues. This paper presents a linear model for the optimal scheduling of synchronous generators and BESs in the joint energy and reserve markets, based on the constraints of primary and secondary frequency services. In the proposed model, the technical limitations of synchronous generators and BESs, the frequency limitation of the grid, rate of change of frequency (RoCoF) of generators, and the RoCoF of the grid are considered as constraints of the optimization problem. Accordingly, the optimal scheduling of the resources is determined in a way that ensures the security criteria of the system are not violated after the contingency. The effectiveness of the proposed strategy is demonstrated by four case studies. Simulation results show that increasing the battery capacity by 4.68% of the total capacity of the system reduces the total frequency reserves, and total costs of the system by 13.21 and 2.96%, respectively. Consequently, system operators can reduce total operating costs and provide adequate security by deploying BESs.The present work has received funding from the European Regional Development Fund (FEDER) through the Northern Regional Operational Program, under the PORTUGAL 2020 Partnership Agreement and the terms of the NORTE-45–2020–75 call - Support System for Scientific and Technological Research - "Structured R&D&I Projects" - Horizon Europe, within project RETINA (NORTE 01-0145-FEDER-000062), and CEEC IND/02887/2017. We also acknowledge the work facilities and equipment provided by GECAD research center (UIDB/00760/2020) to the project team.info:eu-repo/semantics/publishedVersio

The role of the reactor size for an investment in the nuclear sector: an evaluation of not-financial parameters

The literature presents many studies about the economics of new Nuclear Power Plants (NPPs). Such studies are based on Discounted Cash Flow (DCF) methods encompassing the accounts related to Construction, Operation & Maintenance, Fuel and Decommissioning. However the investment evaluation of a nuclear reactor should also include not-financial factors such as siting and grid constraints, impact on the national industrial system, etc. The Integrated model for the Competitiveness Assessment of SMRs (INCAS), developed by Politecnico di Milano cooperating with the IAEA, is designed to analyze the choice of the better Nuclear Power Plant size as a multidimensional problem. In particular the INCAS’s module “External Factors” evaluates the impact of the factors that are not considered in the traditional DCF methods. This paper presents a list of these factors, providing, for each one, the rationale and the quantification procedure; then each factor is quantified for the Italian case. The IRIS reactor has been chosen as SMR representative. The approach and the framework of the model can be applied to worldwide countries while the specific results apply to most of the European countries. The results show that SMRs have better performances than LRs with respect to the external factors, in general and in the Italian scenario in particular

Review of the Reserves and Operable Capability Markets: New England's Experience in the First Four Months

I review the performance of the operating reserves and the operable capability markets in New England. The review covers the first four months of operation from May 1 to August 31, 1999. The review is based on my knowledge of the market rules and their implementation by the ISO, and the market data during this period, including bidding, operating, and settlement information. In the review, I (1) identify the potential market flaws with these markets, (2) look at the performance of the markets to see if the potential problems have materialized, (3) evaluate the ISO's short-term remedies for these market flaws, and (4) propose alternative medium-term solutions to the identified problems. I find that the OpCap and reserve markets have serious flaws that must be addressed. The ISO's short-term fixes have been necessary and effective at addressing the immediate problems. However, better solutions can be adopted in the medium term. In particular, I recommend (1) eliminate the OpCap market, (2) establish a downward sloping demand curve for reserves, (3) pay the clearing price to all resources that provide the service, (4) establish the true real-time supply curve as simply the quantity of the resource made available in real time, (5) establish back down bids in the TMSR market (bids would be infrequent, perhaps monthly), (6) never set a price in the TMSR market less than the largest lost opportunity cost, (7) continue to cascade the quantities of the bids between operating reserve products, and (8) correct the classification of off-line units that provide a service that looks and acts like TMSR. All of these changes are consistent with the long-term solutions proposed for NEPOOL. These changes represent an important step toward the long-term solution involving multi-settlement energy and reserve markets. These markets should be designed carefully to address the basic economic and engineering issues necessary for an efficient wholesale electricity market.Auctions, Electricity Auctions, Multiple Item Auctions

Requirements to Testing of Power System Services Provided by DER Units

The present report forms the Project Deliverable ‘D 2.2’ of the DERlab NoE project, supported by the EC under Contract No. SES6-CT-518299 NoE DERlab. The present document discuss the power system services that may be provided from DER units and the related methods to test the services actually provided, both at component level and at system level

Frequency regulation in wind integrated power system

This Thesis has broader implications in terms of improvement in wind generation modeling which is a current requirement for prospective operational planning tools for future grid. This thesis mainly deals with various modelling issues encountered in wind integrated power system for frequency regulation. Thesis provides development of grid code compatible, frequency responsive type 4 wind turbine generator system and analysis of the wind energy systems frequency regulation capability and their integration impact on interconnected power system.<br /

A review of co-optimization approaches for operational and planning problems in the energy sector

This paper contributes to a comprehensive perspective on the application of co-optimization in the energy sector – tracking the frontiers and trends in the field and identifying possible research gaps – based on a systematic literature review of 211 related studies. The use of co-optimization is addressed from a variety of perspectives by splitting the studies into ten key categories. Research has consistently shown that co-optimization approaches can be technically challenging and it is usually a data-intensive procedure. Overall, a set of techniques such as relaxation, decomposition and linear approaches have been proposed for reducing the inherent nonlinear model's complexities. The need to coordinate the necessary data from multiples actors might increase the complexity of the problem since security and confidentiality issues would also be put on the table. The evidence from our review seems to suggest a pertinent role for addressing real-case systems in future models instead of using theoretical test cases as considered by most studies. The identified challenges for future co-optimization models include (i) dealing with the treatment of uncertainties and (ii) take into account the trade-offs among modelling fidelity, spatial granularity and geographical coverage. Although there is also a growing body of literature that recognizes the importance of co-optimization focused on integrating supply and demand-side options, there has been little work in the development of co-optimization models for long-term decision-making, intending to recognize the impact of short-term variability of both demand and RES supply and well suited to systems with a high share of RES and under different demand flexibility conditions. The research results represent a further step towards the importance of developing more comprehensive approaches for integrating short-term constraints in future co-optimized planning models. The findings provide a solid evidence base for the multi-dimensionality of the co-optimization problems and contriThis work is supported by the National Council for Scientific and Technological Development (CNPq), Brazil. This work has been supported by FCT – Fundaça˜o para a Ciˆencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Endogenous Approach of a Frequency-Constrained Unit Commitment in Islanded Microgrid Systems

Power reserves are usually scheduled in day-ahead unit commitment (UC) to minimize operating costs while maintaining system security. In applying basic UC (bUC) after a contingency, the system frequency may fall upon the activation of the load-shedding global control (under-frequency load-shedding or UFLS) limits. Small isolated microgrids are more sensitive to this issue due to their lack of inertia. Including dynamic considerations into the bUC problem can minimize UFLS activation and also avoid the need for the operator to later check the short-term feasibility of a bUC solution. These proposals are known as Frequency-Constrained UC (FCUC), although the implementation are very time-consuming. FCUC implementation will increase the system’s operational costs, which should be calculated to estimate remuneration to the safety service based on the additional reserve provision. The electrical system of Gran Canaria island has suffered several episodes of greater blackouts in recent years. Shortly, there will be 242 MW of wind generation installed (26% of the thermal power installed on Gran Canaria). The main objective of this work is to improve the island system reliability by means of an FCUC formulation applied by the system operator in practice, including renewable sources. The results show that the frequency values remained within the admissible boundaries, but the system’s operational costs increased by around 13%.This work was supported by VILLUM FONDEN under the VILLUM Investigator Grant (no. 25920): Center for Research on Microgrids (CROM); www.crom.et.aau.dk, accessed on 1 May 2021. 1-This work was supported by the Spanish Ministry of Innovation under Grant PID2019- 104449RB-I00. 2-This work was supported by VILLUM FONDEN under the VILLUM Investigator Grant (no. 25920): Center for Research on Microgrids (CROM); www.crom.et.aau.dk, accessed on 1 May 2021.Publicad