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This paper provides a new methodology to compute a reduced but accurate network representation in a transmission expansion planning (TEP) context. Considering this reduced network should lead to the same investment decisions as if the whole original network were considered. A set of relevant lines to be preserved is defined based on a proxy of the TEP solution. An optimal network partition, resulting from solving the multicut problem, is computed in such a way that the two ends of each of these relevant lines are allocated to two different areas. An iterative Kron reduction is then applied to each area to eliminate most of the buses that are not connected to any interarea line. This two-step process results in a compact but representative reduced network. Our algorithm has been implemented in General Algebraic Modelling Software and Matrix Laboratory and has been tested on the standard IEEE 118 bus system and a case study based on the European power system. The method produces very promising results and, in the considered case studies, leads to the same, or equally efficient, investment decisions and essentially the same total costs as when considering the whole original network. [ABSTRACT FROM AUTHOR]

Parties to the Internal Electricity Market of the European Union (IEM) decided in 2001 to abolish the method of pan-caking of transmission tariffs for cross-border transactions that was originally in place. Instead, they have agreed to implement a system whereby national transmission tariffs provide access to the entire IEM. This system is supplemented by a scheme of inter-TSO payments. However, conflict may arise if the compensation that a country must pay another one is not in accordance with the electrical usage that the former is making of the grid of the latter. For instance, Inter TSO Compensation methods (ITC methods) implicitly allocate the cost of any existing or new transmission line. Therefore, the adoption of an inefficient method may be an obstacle for building some needed regional grid investments. Consequently, one should give careful consideration to the selection of the ITC method. This paper analyzes, both qualitatively and quantitatively, the implementation of the most relevant ITC methods that have been considered so far in the European debate. When assessing each method from a conceptual point of view, considerable attention is devoted to the critical examination of its main underlying assumptions. [ABSTRACT FROM AUTHOR]

Electricity transmission contracts allocate scarce resources, allow hedging against locational price differences, and provide information to guide investment. However, ownership of transmission contracts might enhance market power of strategic generators. If the allocation mechanism for transmission contracts does not prevent generators from obtaining market power-enhancing contracts, explicit restrictions on owning transmission contracts might be required. To ensure that these restrictions do not interfere with the need to hedge for transmission price risk, one proposal is to define all transmission contracts to a balancing point at which energy is traded. Generators are only allowed to own transmission contracts toward this balancing point. Traders or load hedge the price risk from this balancing point to the location of load with transmission contracts. We propose an algorithm and apply it to the European electricity network to identify a balancing point that reduces market power of generation companies and is well connected. Market-level data or detailed information about demand are not required. The only critical input is assumptions on future transmission constraint patterns. [ABSTRACT FROM AUTHOR]

This paper investigates the application of adaptive control to the Spanish load-frequency regulation scheme, Automatic Generation Control (AGC). The Spanish AGC system regulates the frequency and the power exchange between France and Spain. The system is hierarchically structured with one master regulator that coordinates four control areas. Each control area is composed of several generating units providing AGC service. Co-ordinating signals are sent to the control areas so that the global system response achieves the objective established by the System Operator. The participation of each control area in the service is set according to the rated share that it has obtained in the secondary-reserve market and its relative response speed compared to that of the rest of the control areas. Some problems, such as the lack of sensitivity to the quality of the reserve provided by the control areas, have been detected in the operation of the current AGC scheme. A new design, which is presented in this paper, has been developed in order to overcome these problems. This paper attempts to outline how this new design improves the global AGC system response and the distribution of the regulation effort among the control areas. The proposed strategy is compared with the present design by means of simulation. [ABSTRACT FROM AUTHOR]