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This paper tackles the key challenges for dynamics, control, and automation of power systems that are imposed by the integration of renewable power plants. First, the current practice of automation and control in large-scale power systems are reviewed. Then, dynamics and control of electrical transmission systems are discussed and the issues associated with the integration of large-scale wind and solar power plants are exploited. The discussion carries on with a focus on control of electrical distribution systems and the key issues associated with the integration of distributed generation power plants. An emerging concern in power and energy industry is the dynamic interaction between transmission and distribution systems as a result of technological and topological changes in power systems that can put their control at risk. These topics are also covered in this paper. In terms of automation, the key challenges and opportunities for accommodation of higher penetration and share of renewable energy, as part of the vision for grid modernization, are explored in this paper. Throughout the discussion, some results from the recent studies are shown. This article is categorized under: Energy Infrastructure > Systems and Infrastructure K E Y W O R D S automation, control, dynamics, power systems, renewable energy, stability 1 | INTRODUCTION Power systems are compounded of hundreds of thousands of controllable and noncontrollable components that function in a variety of ways (Machowski, Bialek, & Bumby, 1997). Hence, this complex process requires a superb automation to sustain the power delivery. In current power systems, energy management system (EMS) and distribution management system (DMS) represent the highest level of automation at transmission and distribution systems, respectively. These automation systems include the supervisory control and data acquisition systems and a set of real-time and off-line power system applications. The automation and control of traditional power systems with centralized dispatchable power plants and also the stability related issues have been extensively studied and discussed in the literature, including the studies by

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Summary The contemporary concept of Smart Distribution Grid motivates researchers to develop more and more efficient Distribution Management System (DMS) as the basic platform of this concept. This paper deals with power flow as the basic DMS calculation. Procedures for this calculation are usually classified as branch oriented [back/forward sweeping (BFS)] and bus oriented [current injection and Newton/Raphson derivatives]. The first class is favored in this paper. An industry grade generalized BFS (GBFS) procedure is developed for power flow calculation of unbalanced distribution networks. The most complex distribution networks—“irregular” mixed networks—are particularly stressed. In addition, a very simple dealing with inductive and capacitive couplings between parallel overhead lines is presented. It is proven that GBFS is superior in comparison with other power flow procedures tailored for distribution networks—its robustness is at least equal to the robustness of other procedures, but its efficiency is significantly higher. Copyright © 2014 John Wiley & Sons, Ltd.

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Summary The nature of transmission and distribution networks has drastically changed over the last several decades, due to a high penetration of electronically interfaced energy resources (EIERs). Consequently, the complexity of the operation and the management of these networks have considerably increased. This strongly affected the energy management systems and distribution management systems, especially the power flow calculation as their basic power application. Electronically interfaced energy resources can employ a wide range of control strategies that cannot be represented with traditional single‐phase bus types used for traditional alternating current machines in a symmetrical operation. Power flow is the main subject of this paper, and the main objectives are as follows: (i) to prove that the traditional bus classification—θV (slack bus), PQ, and PV—is not sufficient for an unbalanced power flow formulation and the calculation of emerging large‐scale unbalanced electric networks containing traditional alternating current machines and particularly EIERs; (ii) to introduce a new bus classification suitable for the power flow modeling and calculation of these networks; and (iii) to present a robust and accurate unbalanced power flow method based on the new bus classification and a bus type inspection principle. Numerical tests show that the developed power flow method can be successfully applied in the on‐line calculation mode of both energy management system and distribution management system dealing with large‐scale networks.

We aim to systematically review challenges imposed by emerging distributed energy resources (DERs) to model in two basic distribution management system (DMS) online applications-power flow and short-circuit analysis, as well as to offer a systematic review of potential solutions. In the last decade, electronically coupled DERs became increasingly popular. DERs can employ a wide range of control strategies for power, current, or voltage control, in both normal and faulted conditions. Therefore, DERs cannot be modeled with the traditional PQ (load or generator bus), and PV (generator bus) bus types used for modeling synchronous and induction machines in online power flow calculations. Moreover, because fault currents of DERs are limited to predefined maximal values, electronically coupled DERs cannot be represented with traditional voltage source behind impedance models for online short-circuit calculation (SCC). However, most of the DMS software packages still use the traditional models to represent all DER types, including those that are electronically coupled. This paper shows that there will be high calculation errors in such practice, which makes the system model be an inadequate representation of the system. And this will lead to serious errors in managing, control, and operation of distribution systems. Nonetheless, potential solutions to the challenges are systematically reviewed. Finally, calculation results on a distribution test system with all DER types are used to prove the claim.