TSO-DSO Operational Coordination Using a Look-Ahead Multi-Interval Framework

Abstract

With the rise of distributed energy resources and the increasing activation of flexibility resources by Distribution Systems Operators (DSOs), the Transmission System Operators (TSOs) need to co-ordinate their actions with those of the DSOs. This research uses a look-ahead multi-interval (LA-MI) framework for analyzing this coordination and explores two formulations. Firstly in the exogenous DSO model, a mixedinteger linear program is developed to reflect the pragmatic approach in many real situations whereby the TSO can only anticipate statistically the actions of the DSO. In the embedded DSO model, as a comparator, we propose a new organizational setup for the TSO-DSO operational coordination mechanism. In the resulting bilevel decomposition, a new method to calculate Benders cuts is developed and tested on a modified IEEE 118-bus test system as a transmission network and two modified IEEE 33bus test systems as distribution networks. The benefits of the LA-MI coordination framework are substantial in comparison with the current Look-Ahead Single-Interval (LA-SI) coordination framework widely used in Europe.transmission system at time t (M W/M V ar). P T S bct /Q T S bct Active/Reactive power flow from bus b to bus c in transmission system at time t (M W/M V ar). P DS ijbt /Q DS ijbt Active/Reactive power flow from bus i to bus j of a distribution system which is connected to bus b of a transmission system at time t (M W/M V ar). P DS g pt /Q DS g pt Active/reactive consumption for the embedded DSO model at point of common coupling at time t (M W/M V ar). (θ/v s ) (b/i)t Phase angle/Square of voltage magnitude at bus b/i in transmission/distribution systems at time t. β U P bt /β DW bt Binary variables that represent the state of up/down operating reserve activation at bus b and time t for the exogenous DSO activation model. It also represents the concept of implication in the inference dual theorem in the embedded DSO activation model. α U P ubt /α DW dbt Binary variables that represent the state of up/down EERs activation at bus (u/d) ∈ {N ub /N db } of distribution systems which is located at bus b of a transmission system at time t for the exogenous DSO activation model. It also represents the concept of implication in the inference dual theorem in the embedded DSO activation model. λ/Π/µ/δ Dual variables of equality constraints (1b)-(1e). D/Y Dual variables of complementary slackness conditions/Logical indicators. Γ Boundary for the determined Benders cuts in the LBBD model. g Binary variables that reflect combination of complicating variable. Ĝ Boolean variables for different combinations of complicating variables in LBBD. Abbreviations T SO/DSO Transmission/Distribution system operator. T S/DS Superscript for transmission/distribution system. DR/EER Demand response/Embedded energy resource. GDP Generalized disjunctive programming. LA − M I Look-ahead multi-interval.

A Stochastic Inference-Dual-Based Decomposition Algorithm for TSO-DSO-Retailer Coordination

“…This paper is a major extension of the previously published paper [2] on the TSO-DSO operational coordination framework in a deterministic setting. Accordingly, as compared to [2], the contributions of this paper are as follows:…”

“…introduces real-time uncertainties and operational risks that need to be effectively managed to ensure reliable and efficient power system operations. Moreover, the traditional approach of independent bilateral contracting between these parties and EER operators leads to suboptimal outcomes, as it fails to consider the interdependencies and cross-impacts among the stakeholders [2].…”

“…Importantly, this agency would not share the collected data but would focus on facilitating efficient coordination among the stakeholders involved, ultimately leading to improved operational efficiency. We refer to this agency as the Flexibility Market Operator (FMO) and there is already evidence of their emergence [2], [14]. In our formulation, the FMO is an independent, regulated organization through which all market participants who want to buy or sell local flexibility services must trade under their license conditions.…”

“…Nevertheless, energy storage systems introduce distinct inter-temporal and orthogonal constraints into the overall coordination process involving TSO-DSO-Retailer interactions. In a previous paper [2], we extensively discussed an optimization technique for the effective handling of energy storage systems. Hence, for the sake of simplicity here, as in [10], we have excluded the optimization of energy storage systems, given our model's capability to effectively address a large number of intertemporal and orthogonal constraints, as necessary.…”

Cooperative Control of TSO and DSO: Management of Line Congestion and Frequency Response

“…However, the computational burden of method was not considered. In [24], the look-ahead multiinterval framework was used for the TSO-DSO operational coordination and the voltage and congestion problems were successfully solved.…”