| 1. |
- Mercuri, E., et al.
(author)
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Safety and effectiveness of ataluren: comparison of results from the STRIDE Registry and CINRG DMD Natural History Study
- 2020
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In: Journal of Comparative Effectiveness Research. - : Becaris Publishing Limited. - 2042-6305 .- 2042-6313. ; 9:5, s. 341-360
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Journal article (peer-reviewed)abstract
- Aim: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, multicenter registry providing real-world evidence regarding ataluren use in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). We examined the effectiveness of ataluren + standard of care (SoC) in the registry versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS), DMD genotype-phenotype/-ataluren benefit correlations and ataluren safety. Patients & methods: Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established disease progression predictors (registry cut-off date, 9 July 2018). Results & conclusion: Kaplan-Meier analyses demonstrated that ataluren + SoC significantly delayed age at loss of ambulation and age at worsening performance in timed function tests versus SoC alone (p <= 0.05). There were no DMD genotype-phenotype/ataluren benefit correlations. Ataluren was well tolerated. These results indicate that ataluren + SoC delays functional milestones of DMD progression in patients with nmDMD in routine clinical practice. ClinicalTrials.gov identifier: NCT02369731. ClinicalTrials.gov identifier: NCT02369731.
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| 2. |
- Biggar, Darryl R., et al.
(author)
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Towards a Theory of Optimal Dispatch in the Short Run
- 2011
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Conference paper (peer-reviewed)abstract
- In a typical liberalized wholesale electricity market, the output of controllable units is determined at regular intervals through a dispatch process. However, since the physical limits of power systems must be respected down to time scales shorter than the dispatch interval, in practice system operators must also be able adjust the output of controllable units over very short time frames - typically through the procurement and dispatch of reserves, ancillary services or balancing services. To date, the procurement and dispatch of balancing services has been guided by heuristics and rules of thumb. Yet the approach to the dispatch of balancing services can have a significant impact on the pre-contingent or system normal dispatch of the power system. In principle, improvements in the efficiency of the dispatch of balancing services could significantly improve the efficiency of the utilization of power system assets. This paper observes that the dispatch of balancing services should correspond to optimal dispatch in a dispatch process with a very short dispatch interval. We also identify a set of conditions which the procurement and dispatch of balancing services should satisfy and compare those conditions to the current arrangements for ancillary services in the Australian National Electricity Market.
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| 3. |
- Hesamzadeh, Mohammad R., et al.
(author)
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Computation of extremal-nash equilibria in a wholesale power market using a single-stage MILP
- 2012
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In: IEEE Transactions on Power Systems. - 0885-8950 .- 1558-0679. ; 27:3, s. 1706-1707
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Journal article (peer-reviewed)abstract
- This letter proposes a new approach to the computation of extremal-Nash equilibria in a wholesale power market with transmission constraints. The approach uses linearization techniques to formulate the extremal-Nash equilibrium problem as a single-stage mixed-integer linear programming problem which can be solved with standard software. Through the introduced concept of extremal-Nash equilibria, the derived structure can efficiently locate all Nash equilibria of the game. We show that this approach offers significant performance improvements over existing approaches to computing Nash equilibria.
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| 4. |
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| 5. |
- Hesamzadeh, Mohammad R., et al.
(author)
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The TC-PSI indicator for forecasting the potential for market power in wholesale electricity markets
- 2011
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In: Energy Policy. - : Elsevier BV. - 0301-4215 .- 1873-6777. ; 39:10, s. 5988-5998
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Journal article (peer-reviewed)abstract
- Wholesale electricity market regulators have long sought a simple, reliable, transparent indicator of the likely impact of wholesale market developments on the exercise of market power. Conventional indicators, such as the Pivotal Supplier Indicator (PSI) and the Residual Supply Index (RSI) cannot be extended to apply to meshed transmission networks, especially when generating companies hold a portfolio of generating units at different locations on the network. This paper proposes a generalisation of these standard measures termed the "Transmission-Constrained Pivotal Supplier Indicator (IC-PSI)". The TC-PSI of a generating company is defined as the maximum must-run generation for any subset of generating plant while allowing for strategic operation of other plant in the portfolio. We illustrate the use of the TC-PSI using a five-node model of the Australian NEM.
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| 6. |
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| 7. |
- Sarfati, Mahir, et al.
(author)
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Probabilistic pricing of ramp service in power systems with wind and solar generation
- 2018
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In: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 90, s. 851-862
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Journal article (peer-reviewed)abstract
- This paper proposes a probabilistic pricing which achieves efficient operation of and investment in ramp-service providers in power systems with a large amount of wind or solar generation. The proposed pricing differs from the existing literature in that it focuses exclusively on the efficient dispatch of electrical energy with no exogenous consideration of the need for reserves or balancing services. The proposed optimal dispatch task determines both the efficient level of any preventive actions taken before a contingency event occurs and the efficient response of the power system - i.e., corrective actions - once an event occurs. We show analytically that the efficient dispatch outcome can be achieved in a decentralized market mechanism provided the market participants are profit-maximizers and price-takers. We show how the total economic benefit of an investment can be decomposed into two components (a) the normal dispatch cost benefit and (b) the economic value of the investment in contributing ramp service to the power system. In order to study different aspects of the probabilistic pricing, the IEEE 30-node example system is deliberately modified. The results show the efficiency of the proposed pricing and the use of the investment model to assess the economic value of ramp-service providers.
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| 8. |
- Tohidi, Yaser, et al.
(author)
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Transmission network switching for reducing market power cost in generation sector : A Nash-equilibrium approach
- 2017
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In: Electric power systems research. - : Elsevier. - 0378-7796 .- 1873-2046. ; 146, s. 71-79
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Journal article (peer-reviewed)abstract
- The transmission network switching is proposed in the literature as a way to improve social welfare in liberalized power markets. 〈7〉 Moreover, exercise of market power by strategic generating companies (Gencos) causes some extra cost in electricity market which can be alleviated by implementing appropriate switching policies. This paper contributes to the existing literature by developing a mathematical model that explores, from an economic perspective, the transmission network switching in the context of market power. The strategic Gecnos are modelled based on the Cournot game. The Nash equilibrium of the game between Gencos is formulated as an equilibrium problem with equilibrium constraint (EPEC). The EPEC problem is transformed to a mixed-integer linear feasibility problem. To handle the multiple-Nash-equilibria situations, the solution concept of the extremal-Nash equilibrium (ENE) is introduced. A mixed-integer linear program (MILP) is derived for finding ENE. The transmission switching decisions are modelled as binary variables controlled by the system operator (TSO). The TSO minimizes the system dispatch cost calculated at ENE and network reconfiguration cost. The TSO minimizes the cost using its transmission switching decisions. The problem faced by the TSO is a mixed-integer bilevel linear program (MIBLP) with binary variables in both upper and lower levels. The upper level models the TSO's action and the lower level the oligopolistic Gencos (competing in Cournot game). A (parallel) branch-and-bound technique is used to solve the developed MIBLP model. An illustrative 3-bus example system and the IEEE-RTS96 are modelled and carefully studied. 〈8〉The numerical results demonstrate that: 1 – the (parallel) branch-and-bound technique can effectively solve the developed MIBLP, 2 – using the developed model, the system operator can change topology of the network by switching the lines in order to reduce the adverse effect of the strategic behaviour of Gecnos.
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| 9. |
- Biggar, D., et al.
(author)
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Designing transmission rights to facilitate hedging
- 2013
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In: 2013 10th International Conference on the European Energy Market (EEM). - : IEEE. - 9781479920082 ; , s. 6607320-
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Conference paper (peer-reviewed)abstract
- In a liberalised wholesale electricity market risk-averse market participants need some form of financial instrument to offset the risks of spot price variation across locations and across time. Some liberalised wholesale electricity markets seek to facilitate transactions across separately-priced nodes by making available an instrument known as a Financial Transmission Right (or FTR). But FTRs are flawed as a hedging instrument. They do not necessarily make available the full set of funds required to allow market participants to hedge locational price differences. Furthermore, conventional FTRs, which are associated with a volume which is fixed in advance, are not useful for hedging transactions where the volume depends on market conditions at the time. This paper proposes introducing a new form of transmission right which mimics the operation of a 'cap' hedge contract. This transmission right can be combined into a portfolio which provides the natural backing for the price-dependent volume-varying hedge that most market participants require. We consider that this new design of transmission rights offers promise as an approach for facilitating hedging and improving market outcomes in wholesale electricity markets.
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| 10. |
- Biggar, Darryl R., et al.
(author)
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An integrated theory of dispatch and hedging in wholesale electric power markets
- 2022
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In: Energy Economics. - : Elsevier BV. - 0140-9883 .- 1873-6181. ; 112
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Journal article (peer-reviewed)abstract
- The literature on optimal dispatch of wholesale power systems implicitly assumes that market participants are risk-neutral. But, in practice, most wholesale electricity market participants behave as though they are risk averse, seeking to insulate themselves from the market risks they face. In this context, achieving the overall social-welfare maximum requires simultaneously finding both the optimal dispatch and optimal hedging arrangements. Assuming that market participants have mean-variance preferences, we show that the dispatch task can be separated from the hedging task. We show how market participants can achieve a perfect hedge by forming a portfolio of inter-temporal hedge contracts. Departing from the previous literature, we assume the system operator is risk averse. We show how the system operator can achieve a perfect hedge using a portfolio of inter-nodal hedging instruments which we refer to as generalised Financial Transmission Rights. The total risk experienced by market participants when optimally hedged is equal to the variation in the total surplus or total economic welfare. This approach therefore leads naturally to a form of merchant transmission investment where network upgrade decisions are carried out by a coalition of risk-bearers in the market. In addition, we propose a natural extension in which transmission network operators provide a form of insurance against network outages, and face the correct social incentive for avoiding network outages. This approach resolves a number of outstanding issues in the economic analysis of power markets.
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