Robust congestion management and service restoration for active distribution networks

• Main Author: Shen,Feifan
• Other Authors: Xu Yan
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Electrical and electronic engineering::Electric power::Production, transmission and distribution
• Online Access: https://hdl.handle.net/10356/153882
• Institution: Nanyang Technological University

In order to reduce greenhouse gas emissions and alleviate energy shortage concerns, it is expected that the distributed energy resources (DERs) will be largely deployed in distribution networks, which could offer various benefits and also pose great challenges to the operation and management of the distribution network. This thesis aims to deal with congestion in distribution networks caused by DERs and to use DERs to facilitate service restoration of distribution networks after contingency. The flexible demands including electrical vehicles (EVs) and heat pumps (HPs) can shift power consumption from peak hours to off-peak hours to minimize energy costs, which consequently leads to congestion in those hours with low electricity prices. This thesis proposes several new market-based methods to alleviate day-head and real-time congestion of distribution networks. Firstly, the thesis proposes to integrate different types of methods, which can combine the advantages of different methods and can resolve congestion more efficiently. Secondly, the uncertainty in the dynamic tariff method is studied and handled by using the robust optimization method. Thirdly, the thesis proposes a two-tier real-time congestion management method to alleviate real-time congestion while considering the customer’s energy rebound conditions and willingness to change day-ahead schedules. These proposed methods can efficiently alleviate congestion of distribution networks caused by the flexible demands, which could facilitate the large-scale integration of DERs in distribution networks. In the case of contingency, service restoration is carried out to restore outage areas. Most of the existing service restoration models are solved by centralized algorithms based on centralized infrastructure, which is faced with a few drawbacks regarding the computation burden, single-point failure risk, and privacy information protection. To overcome the drawbacks, the thesis first proposes a hierarchical service restoration method based on the alternating direction method of multipliers (ADMM), in which the service restoration problem is solved in a hierarchical manner to reduce the computation complexity. Furthermore, this thesis proposes a distributed service restoration method based on the ADMM, in which the service restoration problem is decomposed and solved in a distributed manner. The distributed method is more resilient to controller failures and respects privacy information protection. In order to deal with the uncertainty of DERs and unavailability of power fed by transmission networks, the thesis proposes a distributed risk-limiting service restoration method for the distribution network with networked microgrids (MGs), in which each MG individually uses its local DERs to restore loads without violating risk-limiting constraints of the whole network.