Optimal Network Topology for Node-Breaker Representations With AC Power Flow Constraints

Byungkwon Park,Christopher L Demarco

doi:10.1109/access.2020.2984521

Byungkwon Park, Christopher L Demarco

Open Access

https://doi.org/10.1109/access.2020.2984521

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Abstract

It has been demonstrated that network topology optimization (NTO) may change the topology of power system networks, and consequently, provide additional flexibility to reduce network congestion and violations. Most NTO problems are formulated based on the bus-branch model in which it is challenging to represent a realistic picture of all substation configurations. In this paper, we explore advantages of substation reconfiguration modeling based on node-breaker representations for NTO problem with full nonlinear alternating current power flow. It also proposes a tailored solution algorithm to solve this nonconvex mixed-integer nonlinear programming through the outer approximation method. The proposed solution approach iterates between a mixed-integer linear programming and a nonlinear subproblem. Additional enhancements to further accelerate the iteration process are illustrated. Numerical case studies demonstrate the relative economic and operational impact of optimal network topology with node-breaker representations.

Highlights

Current frameworks to design, control, and optimize largescale energy systems are increasingly challenged by advancing grid technologies and changing operating strategies
This suggests that incorporating the integer decision variables associated with network topology choices could be an important enhancement to the optimal power flow problem (OPF), offering greater flexibility to mitigate congestion/violations in the face of contingencies and uncertainties introduced by variable energy resources
NUMERICAL RESULTS This section presents numerical results to illustrate the effectiveness of the proposed network topology optimization (NTO)-NB-alternating current (AC) formulation and corresponding solution algorithm as well as the relative economic and operational impact of AC optimal power flow (ACOPF) problem with NTO

Summary

INTRODUCTION

Control, and optimize largescale energy systems are increasingly challenged by advancing grid technologies and changing operating strategies. Corrective switching [4], viewed as a discrete control action, can resolve congestion and flow violations at a much lower cost compared to other corrective control methods such as load shedding and generation rescheduling This suggests that incorporating the integer decision variables associated with network topology choices could be an important enhancement to the optimal power flow problem (OPF), offering greater flexibility to mitigate congestion/violations in the face of contingencies and uncertainties introduced by variable energy resources. Our contributions in this work are in the formulation and solution technique for the NTO + NB + AC problem, as well as its applicability to smart grid energy systems as a potential mitigation tool that reduces operating costs and could resolves congestion/violations.

SUBSTATION MODELING

SPARSE TABLEAU FORMULATION FOR POWER SYSTEM NETWORKS

AC POWER FLOW MODEL USING STF

2: Solve the NLP subproblem

NUMERICAL RESULTS

CONCLUSION