The Diversity of Design of TSOs

International audienceIt is puzzling today to explain diversity and imperfection of actual transmission monopoly designs in competitive electricity markets. We argue that transmission monopoly in competitive electricity markets has to be analysed within a Wilson (2002) modular framework. Applied to the management of electricity flows, at least three modules make the core of transmission design: 1° the short run management of network externalities; 2° the long run management of network investment; and 3° the coordination of neighboring Transmission System Operators for cross border trade. In order to tackle this diversity of designs of TSOs, we show that for each of these modules, three different basic ways of managing them are possible. Among the identified twenty seven options of organisation, we define an Ideal TSO. Second, we demonstrate that 1°monopoly design differs from this Ideal TSO and cannot handle these three modules irrespective of the “institutional” definition and allocation of property rights on transmission; while 2°definition and allocation of property rights on transmission cannot ignore the existing electrical industry and transmission network structure: they have to complement each other to be efficient. Some conclusions for regulatory issues of transmission systems operators are derived from this analysis of network monopoly organisation

Experimental study of the reduction of field emission by gas injection in vacuum for accelerator applications

LGEP 2014 ID = 1590International audienceField emission current from surfaces under vacuum and at high field strengths can be reduced by the injection of gas into the evacuated volume. In this paper, the effects of H 2 , He, N 2 , and Ar on this "dark" current emitted from a tungsten carbide point cathode for 2 cm gap distance is studied. Exposure to any of these gases at pressures on the order of 10 −3 –10 −2 Pa was found to reduce the emission current by up to 90% with a time constant on the order of ∼1 minute as compared to the current at 10 −6 Pa. The effect was strongly dependent on the gas nature, with Ar and N 2 having larger effects at lower pressures than He and H 2 . The reduction was reversible, with the current increasing to near its original value with a time constant on the order of ∼1–10 minutes after pumping down. The effect of the gas remained in the absence of electric field, whatever the gas pressure. Mechanisms for these and related phenomena are discussed

2D positive streamer modelling in NTP air under extreme pulse fronts. What about runaway electrons?

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The Diversity of Design of TSOs

It is puzzling today to explain diversity and imperfection of actual transmission monopoly designs in competitive electricity markets. We argue that transmission monopoly in competitive electricity markets has to be analysed within a Wilson (2002) modular framework. Applied to the management of electricity flows, at least three modules make the core of transmission design: 1° the short run management of network externalities; 2° the long run management of network investment; and 3° the coordination of neighboring Transmission System Operators for cross border trade. In order to tackle this diversity of designs of TSOs, we show that for each of these modules, three different basic ways of managing them are possible. Among the identified twenty seven options of organisation, we define an Ideal TSO. Second, we demonstrate that 1°monopoly design differs from this Ideal TSO and cannot handle these three modules irrespective of the “institutional” definition and allocation of property rights on transmission; while 2°definition and allocation of property rights on transmission cannot ignore the existing electrical industry and transmission network structure: they have to complement each other to be efficient. Some conclusions for regulatory issues of transmission systems operators are derived from this analysis of network monopoly organisation.design of TSOs; management of power flows; governance structure of transmission.

Optimal Control Strategy to Design a Hybrid Electrical System

International audienceThe benefit of a hybrid system is strongly dependant on the system design and the control strategy that will be used. This paper suggests a method to evaluate the optimal control strategy of a hybrid electrical system to optimize its design from the point of view of fuel consumption taking into account this interaction. Analytic models are used to describe the system and the interactions between components. A first optimization is made to minimize fuel consumption using one system configuration on a typical consumption cycle. This algorithm is ready to be using with a higher level algorithm in order to find an appropriate design of the system

Global optimization of hybrid electrical system to decrease fuel consumption or operating cost

International audienceHybrids systems benefits are strongly dependent on the system design and the control strategy. The strategy choice strongly affect sizing and vice versa. This phenomenon is not always taken into account which leads to a non-optimal sizing of the system. This paper suggests a new method to optimize the design of hybrid power generator system from the point of view of fuel consumption taking into account this interaction. The main idea is to calculate the optimal control strategy of the system energy flux. Then, we can perform, for a given load profile, an optimization of the whole structure to find the best sizing

Simulation of 3D Streamer branching using High Performance Computing

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Relative contributions to the emission within bundles of carbon nanocone emitters

International audienceHerein, an original design of electron source based on an array of carbon nanocone bundles has been modeled. The contribution to the emission within bundles is investigated using a cold emission model based on the WKB approximation. The case of a specific bundle is presented where the geometry of the nanocones leads to a change of the main emitter as the voltage is ramped up. This change is shown to alter the linearity of usual Fowler-Nordheim analysis of the simulated I(V) data

Borehole water level model for photovoltaic water pumping systems

International audienceHighlights: • A borehole water level model for photovoltaic water pumping systems is developed. • The model is validated against experimental data and has an accuracy of 97%. • The model allows us to study the influence of water resources on the system sizing. • The influence of the static water level on the optimal lifecycle cost is about 11%. • The influence of the drawdown on the optimal lifecycle cost is lower than 2%