Planning and operation of LV distribution networks: a comprehensive review

Abstract

The low‐voltage (LV) distribution network is the last stage of the power network, which is connected directly to the end‐user customers and supplies many dispersed small‐scale loads. To achieve environmental targets and to address the energy shortage issue, governments worldwide increase the renewable energy sources (RESs) into the electricity grid. In addition, different types of low carbon technologies (LCTs) such as electric vehicles are becoming widely used. A significant portion of RES and LCTs is penetrated into the LV distribution network, which poses a wide range of challenges. To address these challenges, there is a persistent need to develop traditional planning and operation frameworks to cope with these new technologies. In this context, this study provides a comprehensive review of planning, operation, and management of LV distribution networks. The characteristics, types, and topologies of LV distribution networks plus different aspects of operation and planning are investigated. An insightful investigation of the reasons impacts and mitigation of voltage and current unbalanced in LV networks is provided. Moreover, the main three‐phase power flow techniques used to analyse the LV networks are analysed.

Sizing of Hybrid Energy Storage Systems for Inertial and Primary Frequency Control

“…Hence, the analysis of the ESS dynamic response is only one step of the problem, which requires integration into a broad optimization involving several time scales. Nonetheless, an inspection of recent literature reviews on ac MG planning (Gamarra and Guerrero, 2015;Al-Jaafreh and Mokryani, 2019) reveals that conditions for frequency stability are largely overlooked in the problem formulation, and most optimization algorithms consider that matching power demand with generation is the only required dynamic constraint, without imposing minimum requirements on system damping or frequency reserves. This is typically justified by the argument that frequency stability analysis in ACPSs requires computationally demanding simulation models that can turn the optimization into an intractable problem.…”

Decentralized Voltage Control Strategy of Soft Open Points in Active Distribution Networks Based on Sensitivity Analysis

“…After the clustering result is obtained, two sub-areas of the terminal nodes are merged into one sub-area under the control of the related SOP. Then, the number of cluster centers N C is determined by (2).…”

“…The growing penetration of distributed generators (DGs), such as wind turbines (WTs) and photovoltaics (PVs), brings a series of operational problems to active distribution networks (ADNs), especially severe voltage violation [1,2]. Novel power electronic equipment represented by soft open points (SOPs) can effectively cope with the problems through accurate active and reactive power flow controls.…”

Sufficient Conditions for Robust Frequency Stability of AC Power Systems

“…Specifically, guaranteeing frequency stability of low-inertia systems can be a major challenge and requires proper sizing of dispatchable power sources and energy storage. Nevertheless, an inspection of recent literature reviews on ac MG planning [14], [15] shows that conditions for frequency stability are largely overlooked in the problem formulation. Specifically, most optimization algorithms assume that matching power demand with production is the only required dynamic constraint, without imposing minimum requirements on system damping or frequency containment reserves (FCR).…”