Implementation of different methods for PTDF matrix calculation in flow-based coordinated auction

Abstract

Flow-based coordinated auctioning (CA) is crossborder transmission capacity allocation mechanism. The SouthEast European (SEE) Transmission system operators (TSOs) launched the investigation of this method, based on better representation of physical behavior of interconnected electric systems than those widely used on most of the European borders. CA uses flow-factors (PTDF -Power Transfer Distribution Factors) to convert the commercial exchanges into their physical influence on the cross-border flows, and Border Capacities (BC) as physical limitations for those flows. The goal of this paper is to conduct a numerical comparison between different methods used for PTDFs calculation.

Impact assessment of a minimum threshold on cross-zonal capacity in a flow-based market

“…Table 4 shows the total annual consumers' payments, only at the market level. 7 When a minimum RAM of 70% is enforced, they tend to decrease because the zonal costs tend to decrease (virtual increase of the interconnection capacity).…”

“…For example, Purchala et al [5] and Bart and Andreewsky [6] discuss the feasibility of a FB zonal model for the UCTE grid, and different ways of grouping the nodes of a network into zones and of computing associated transfer limits using zonal PTDFs, respectively. In [7], the impact of different ways to define GSKs on the zonal PTDFs for the border between Montenegro and Albania is assessed. First methodologies to simulate a FB market are then proposed in Waniek et al [8], Louyrette and Trotignon [9], Barth et al [10].…”

“…In line with what is proposed in Van den Bergh et al [12], but considering security constraints, we propose to obtain this base case through a Preventive Security-Constrained Optimal Power Flow (PSCOPF). The optimization problem can then be formulated as C P min g g g (7) such that…”

Web-based simulation tools for the allocation of cross-border transmission rights and implementation aspects in South-East Europe

“…Otherwise, proportional generation shift according to power reserve of the modeled power plants will be used. Inaccuracy of the PTDF model due to its inherent assumption of linear generation dispatch as opposed to merit order in reality and geographical distribution of generation within modeled zones is covered by Flow Reliability Margin (FRM) [6]. This value represents a physical power flow at the border between the two areas taken as a security margin that copes with uncertainties on the calculated TBC values.…”

Implementation aspects of partial netting in flow-based auction clearing mechanism

“…In that way, additional electricity exchange between the zones X and Y is simulated. Change of generation in both systems is done in PV nodes, proportional to engagement of each power plant in the initial base case [5]. PTDFs are calculated on the mathematical model of EPS by means of specialized software for load-flow calculation and with the usage of lossless DC load-flow, which for this appliance has a number of advantages over the AC load-flow.…”