• Energy Research

Smart meters (SM) generate critical data that provides real-time insights into energy consumption, grid performance, and load management, which are essential for improving grid reliability, energy efficiency, and renewable energy integration. However, achieving effective communication between smart meters and the control center remains a challenge due to limitations in Advanced Metering Infrastructure (AMI), including communication delays, metering technology constraints, and restricted data storage and processing capabilities. These limitations hinder the precision and timeliness of real-time data delivery, negatively impacting the efficiency of energy management and grid operations. While existing research predominantly focuses on optimizing communication network algorithms, the critical issue of comprehensive SM data scheduling has received limited attention. Moreover, current methods often fail to account for the complexity of communication networks and the dynamic nature of information flow. To address this gap, this paper introduces a novel method for scheduling SM data access by leveraging real-time data assessment and analysis. A quality metric termed mismatch probability evaluates data quality, and the Hungarian algorithm is employed to optimize meter scheduling. The proposed method is validated using real-world data from a Danish grid, demonstrating significant improvements in information quality for real-time monitoring compared to heuristic-based scheduling approaches.

The penetration of renewable energy into the electricity supply mix necessitates the traditional power grid to become more resilient, reliable and efficient. One way of ensuring this is to require renewable power plants to have similar regulating properties as conventional power plants and to coordinate their grid support services (GSS) as well. Among other requirements, the coordination of GSS will highly depend on the communication between renewable plants and system operators’ control rooms, thereby imposing high responsibility on the under lying communication infrastructure. Despite such a widespread deployment, it is still neither completely known which communication technology solutions are currently in use, nor it is clear which of these technologies best fit to access and control these renewable plants in future. This is because of varying communication requirements for different GSS applications – in terms of data payloads, sampling rates, latency and reliability. Therefore, this paper presents a brief survey on the control and communication architectures for controlling renewable power plants in the future power grid, including the communication network technologies, requirements, and research challenges. To help identifying research problems in the continued studies, this paper attempts to ascertain how the underlying protocols in a communication stack influence timely and reliable communication in the said scenario.

Data integration from heterogeneous data sources in low-voltage (LV) power distribution grids will be valuable to distribution system operators (DSOs). The power measurements from customer premises need to be processed with other data such as grid topology, line parameters etc., to deploy smart grid applications (SGA) such as real-time grid monitoring and voltage regulation. The most challenging task for DSOs is to collect and integrate data from several sources as several entities are involved in the data management and access to databases are restricted. This paper presents an opEn common information Model (CIM) BAsed smaRt grid application frameworK (EMBARK) to address the above-mentioned challenge. EMBARK is developed to be an efficient, modular and scalable architecture for extracting relevant grid related information from various asset management databases. A novel data management functionality is a part of EMBARK that enables data-driven update of settings and parameters of the algorithms behind smart grid applications. The proposed approach is demonstrated and numerically validated using grid data from a medium-sized distribution grid operator in Denmark. The architecture developed and presented in this paper can support all the phases from planning to the actual smart grid operation i.e., automatically building the models to perform load flows, grid impact studies, planning, asset management etc.

Time is critical for certain types of dynamic information (e.g. frequency control) in a smart grid scenario. The usefulness of such information depends upon the arrival within a specific frame of time, which in other case may not serve the purpose and effect controller’s performance. In this context, transport layer offers different levels of end-to-end communication services to the applications. For instance, TCP guarantees the transport of messages between two ends, however, at the cost of high end-to-end delays due to the retransmission mechanism. Whereas UDP offers minimum end-to-end delays at the cost of unreliable, best-effort data transportation service. The research question raised in this paper is thus, which is preferred for the delay-critical applications of smart grids, and to what degree of packet losses and round trip times, TCP is preferable to UDP and vice versa. The question is addressed by analyzing the performance of UDP and TCP over imperfect network conditions to show how the selection of transport layer protocol can dramatically affect controller’s performance. This analysis is based on a quality metric called mismatch probability that considers occurrence of events at grid assets as well as the information update strategy in one single metric which otherwise is not very intuitive and difficult to allow a similar useful comparison. Further, the analysis is concluded by providing a clear guide on the selection of the transport protocol to meet application requirements.

The road between the conventional energy grids and smart energy systems involves, among other things, the validation of smart energy systems enabling-technologies. Such validation is not always possible on-site, so it must be performed in laboratory conditions. In fact, when large electrical grids are targeted together with their information management system the development and testing of smart grid enabling-technologies are possible, in most cases, only in the laboratory. This paper presents a flexible laboratory platform developed for the study, testing and validation of smart grids and smart energy systems enabling-technologies, including Power Hardware-In-the-Loop and Information and Communications Technology.

Renewable energy sources (RES) such as solar and wind has emerged as the fastest growing energy sources. The growth of their deployment in the power sector leads to several challenges, for example, voltage violation, power quality issues, power losses etc. One of the several strategies to overcome the voltage violation problem is the provision of reactive power from the PV inverters. Local controller of the photo voltaic (PV) inverters coordinates with the coordinated controller to generate the reactive power. The coordinated controller performs its function based on the information obtained from the whole grid via underlying communication network. This imposes a high responsibility over the communication network infrastructure in order to ensure a reliable and stable voltage control in distribution grids (DGs). This paper, therefore, analyses the impact of communication networks on the voltage quality control supported by the reactive power generation of PV plants in DGs. Further, a voltage coordination scenario is presented based on an actual grid by a local distribution system operator (DSO) in Denmark. This paper evaluated the network performance in terms of network delays in the signal, being transferred between the smart meters of the grid and coordinated controller.

This paper proposes a hierarchical coordinated control strategy for PV inverters to keep voltages in low-voltage (LV) distribution grids within specified limits. The top layer of the proposed architecture consists of the designed automatic voltage regulation (AVR) application, which has access to voltage measurements and grid parameters from the LV distribution grid, both current and historical. The AVR application solves a constrained optimization problem, which provides a set of local control set-points that bring the voltage across the grid within bounds. The middle layer consists of a local Volt/VAR controller, which is adjusted by the AVR app, while the bottom layer is the inner-loop controller of the PV inverter. The proposed method not only improves the voltage quality in the grid but also manages the reactive power outputs of PV inverters efficiently. A digital twin of the cyber-physical system has also been employed that interacts with the control system to ensure its appropriate operation. The effectiveness of the proposed methodology is demonstrated on a representative low-voltage feeder located in Denmark.

The increased penetration of Renewable Energy Generation (ReGen) plants in future power systems poses several challenges to the stability of the entire system. In future green energy rich power systems, the responsibility for providing ancillary services will be shifted from conventional power plants towards ReGen plants, such as wind and photovoltaic power plants. Frequency control support from the Wind Power Plants (WPPs) is one of the crucial ancillary services in order to preserve operational stability in case of grid disturbances. Among other requirements, the ability to provide fast frequency control support from ReGen plants will highly depend on the underlying communication infrastructure that allows an exchange of information between different ReGen plants and the control centers. This paper, therefore, focuses on the evaluation of the impact of communication and the related aspects to provide online frequency control support from ReGen (with special focus on WPP). The performance evaluation is based on an aggregated WPP model that is integrated into a generic power system model. This generic power system model is specifically designed to assess the ancillary services in a relatively simple yet relevant environment. Several case studies with different wind speeds at a particular wind-power penetration level and communication scenarios are considered to evaluate the performance of power system frequency response. The article provides the Transmission System Operator (TSO) and other communication engineers insights into the importance and various aspects of communication infrastructure for general service coordination between WPPs and specifically primary frequency control coordination from WPPs in future power systems.