Methodological Approach for Defining Frequency Related Grid Requirements in Low-Carbon Power Systems

Abstract

Moving towards low-carbon electricity systems through the massive deployment of renewable energy sources (RES) presents a unique opportunity to combat climate change, but it also poses enormous technical challenges, especially from a frequency viewpoint. To ensure a secure RES integration in terms of frequency stability, system operators worldwide have adopted new grid codes requiring RES to provide fast frequency response (FFR). However, if not properly justified, stringent requirements may pose an unnecessary barrier to further RES development and slow their network integration. In this context, this paper presents a methodological framework for systematically defining FFR requirements for RES to ensure system frequency stability. The proposal comprises: i) a model for simulating the dynamic response of system frequency following a contingency with reduced computational effort, ii) a model for reallocating contingency reserves with economic criteria to avoid loss of load following a contingency, and iii) novel indices for characterizing the dynamic performance of system frequency in terms of key operational characteristics, which are then used for defining frequency related grid codes. The benefits and practicability of our proposal are demonstrated in a case study on the Northern Interconnected System in Chile. We show how our proposal can be used to i) identify system operating conditions in which the contribution of RES with FFR is necessary to avoid loss of load and ii) to propose a technically and economically justified grid code that allows both to foster further RES integration while ensuring power system security.

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

“…Various recent studies have investigated the potential role of wind, photovoltaic (PV), and battery energy storage systems in providing fast frequency services [12][13][14]. However, there have been few empirical studies which have considered such capabilities from demand response (DR) units, albeit some researchers have considered the contribution of DR units to primary frequency response in much more detail [15,16].…”

“… To this end, in this paper, a simplified model of supermarket refrigeration systems is first presented: which can predict the energy consumption of an individual supermarket refrigeration system, while providing reasonably fast computation, such that a sufficiently large and diverse fleet of supermarkets can be simulated and aggregated to system level, while the impact of supermarket occupancy and outdoor temperature are considered. The aggregated model is used to assess the capability of supermarkets to provide a fast frequency response (FFR). As previously mentioned, research to date has tended to focus on FFR capability from wind, PV, and battery energy storage [12–14] rather than DR units, specifically commercial ones. Although extensive research has been performed on traditional system requirements, e.g.…”

Method for Determining the Optimal Capacity of Energy Storage Systems with a Long-Term Forecast of Power Consumption

“…The algorithm for the formation of the cost of electricity and power when consumption exceeded the declared maximum had general principles in different countries. Article [57] discusses a way to reduce consumption peaks in the Chile power system using wind generators and analyzes the existing methods of generating the cost of electricity in the country to maintain the balance of frequency and active power in the system.…”

Prospects and Obstacles for Green Hydrogen Production in Russia

“…In particular, by 2050, China plans to increase the capacity of nuclear power plants to 250 GW, while, according to estimates by The Energy Research Institute [5], industrial storage systems with a total capacity of about 113 GW will be needed to regulate this capacity. In addition, an example of the use of power accumulators is frequency regulation in order to balance supply and demand in the minute phase [6]. For example, Tesla's Hornsdale Power Reserve (100 MW/129 MWh), commissioned in South Australia (≈2% of the installed capacity of the region's power system), is included in the Frequency Control and Ancillary Services System (FCAS).…”