Power system stability in the transition to a low carbon grid: A techno‐economic perspective on challenges and opportunities

Abstract

Increasing power system stability challenges are being witnessed worldwide, while transitioning toward low‐carbon grids with a high‐share of power electronic converter (PEC)‐interfaced renewable energy sources (RESs) and distributed energy resources (DERs). Concurrently, new technologies and operational strategies are being implemented or proposed to tackle these challenges. Since electricity grids are deregulated in many jurisdictions, such technologies need to be integrated within a market framework, which is often a challenge in itself due to inevitable regulatory delays in updating grid codes and market rules. It is also highly desirable to ensure that an economically feasible optimal technology mix is integrated in the power system, without imposing additional burdens on electricity consumers. This article provides a comprehensive overview of emerging power system stability challenges posed by PEC‐interfaced RES and DER, particularly related to low inertia and low system strength conditions, while also introducing new technologies that can help tackle these challenges and discussing the need for suitable techno‐economic considerations to integrate them into system and market operation. As a key point, the importance of recognizing the complexity of system services to guarantee stability in low‐carbon grids is emphasized, along with the need to carefully integrate new grid codes and market mechanisms in order to exploit the full benefits of emerging technologies in the transition toward ultra‐low carbon futures. This article is categorized under: Energy Systems Economics > Economics and Policy Energy Systems Analysis > Systems and Infrastructure Energy and Development > Systems and Infrastructure

Fast frequency response provision from commercial demand response, from scheduling to stability in power systems

“…In this context, the Department of the Environment, Climate, and Communications of Republic of Ireland (ROI) set a 70% renewable electricity target for 2030, with electricity projected to account for ≈ 30% of final energy use in Ireland [2]. One of the challenges of accommodating large shares of renewables in electricity networks is associated with frequency and voltage related stability challenges [3]. One particular aspect relates to the displacement of synchronous generators by converter-interfaced variable renewables technologies, which leads to a reduction in stored rotational energy (inertia), and faster power system dynamics, such that higher rates of change of frequency (RoCoF), lower frequency nadirs, and a higher likelihood of underfrequency load shedding can be expected, particularly in smaller, or (synchronously) isolated power systems, following a significant disturbance [3,4].…”

“…One of the challenges of accommodating large shares of renewables in electricity networks is associated with frequency and voltage related stability challenges [3]. One particular aspect relates to the displacement of synchronous generators by converter-interfaced variable renewables technologies, which leads to a reduction in stored rotational energy (inertia), and faster power system dynamics, such that higher rates of change of frequency (RoCoF), lower frequency nadirs, and a higher likelihood of underfrequency load shedding can be expected, particularly in smaller, or (synchronously) isolated power systems, following a significant disturbance [3,4]. It follows that when a generator trips faster acting frequency responses are required in order to stabilise the system.…”

“…Although extensive research has been performed on traditional system requirements, e.g. primary operating reserve [15], fewer research works have considered new (faster) services, such as FFR, which have grown in importance against a background of power systems operating with increasing shares of nonsynchronous generation [3,11]. It follows that the requirements for DR-based FFR responses have not been fully analysed [11,31], with appropriate frequency control strategies, considering the characteristics of individual load types, such as supermarket refrigeration systems, having been carefully evaluated.…”

“…Considerable effort has focused on low inertia power systems, and the associated challenges and issues [3,13,32,33]. For example, [32] studies the potential of energy storage systems in this regard, while [13] discusses new obligations on RES sources to provide fast responses, and required grid code changes in order to maintain power system stability.…”

Stability Analysis of Grid-Forming MMC-HVDC Transmission Connected to Legacy Power Systems

“…A GFM can control directly its voltage amplitude, frequency, and phase without relying on the strength of the grid. It can provide services such as (but not limited to) black start capability, virtual inertia, primary frequency support, and islanded operation capability [59].…”