A Comparative Analysis of Congestion Management Schemes under a Unified Framework

Abstract

Abstract:The restructuring of the electricity industry has spawned the introduction of new independent grid operators or IGOs, typically called transmission system operators (TSOs), independent system operator (ISOs) or regional transmission organizations (RTOs), in various parts of the world. An important task of an IGO is congestion management (CM) and pricing. This activity has significant economic implications on every market participant in the IGO's region. The paper briefly reviews the congestion management schemes and the associated pricing mechanism used by the IGO's in five representative schemes. These were selected to illustrate the various CM approaches in use: England and Wales, Norway, Sweden, PJM and California. We develop a unified framework for the mathematical representation of the market dispatch and redispatch problems that the IGO must solve in CM in these various jurisdictions. We use this unified framework to develop meaningful metrics to compare the various CM approaches so as to assess their efficiency and the effectiveness of the market signals provided to the market participants. We compare, using a small test system, side by side, the performance of these schemes.

Congestion management in the deregulated electricity market: An assessment of locational pricing, redispatch and regulation

“…Normally, the TSO is the only buyer of curative counter transactions (i.e., supplementary transactions to recover secure network conditions), and their selection is usually based on merit-order criteria or long-term contracts, see [2]. Although there are many options for redispatch, here we only describe cost-based counter trade.…”

“…In Europe, two different congestion management schemes can be distinguished, see, e.g., [1], [2]. Many TSOs correct infeasible outcomes of an unconstrained forward market via congestion redispatch, that is, by requesting counter transactions after gate closure.…”