The islanded mode of operation of an electric power system (EPS) that has generation capabilities provided by conventional thermal power plants, by a pumped-storage power station, or from an interlink with a neighboring electric power system through an HVDC BtB converter is addressed in this paper. The risk for electrical power systems to fall into an islanded mode has recently grown, as it is caused not just by technical reasons but by a geopolitical situation as well. The current strains demand the close consideration of problems related to EPS operation in an islanded mode. This paper considers several. The research covers the following issues. The response of the islanded system to a sudden and spasmodic load change is analyzed in cases when the system deals with the disturbance with internal resources alone and with the help of an HVDC BtB converter’s frequency control functionality. Analysis of the impact of the settings of the HVDC BtB converter on the system’s response to disturbances is presented and the optimal set of parameters found. The impact of the system’s extended inertia on the system’s response is evaluated by using an additional unit of the pumped-storage power station in synchronous condenser mode. Transients in the system when switching a unit operating in synchronous condenser mode on and off are analyzed. The capability of the system to withstand major disturbances, such as disconnection of the pumped-storage power station’s unit operating in a pump mode and disconnection of the HVDC BtB converter in emergency modes, if a situation demands, is researched. The research is carried out by numerical simulations using PSS Sincal Electricity Basic software. Updated operating parameters of the isolated power system and the LCC HVDC BtB converter, as well as frequency control automation provided by ABB, were used in the simulations.

Measurement error in an electromagnetic flow meter appears if magnetic and electric properties of admixtures are different from that of the fluid. Expressions of the error, which depends on volume concentration, permeability, and electric conductivity of particles were obtained by approximating the particles’ shape as an ellipsoid. Components of the error, which appear inside particles and outside particles in active zone of flow meter, with any canal form are investigated. Expressions of the error are presented assuming that particles are oriented in various directions with respect of the flow direction and are spinning. Different cases of magnetic and electric admixtures properties are discussed. Error expression obtained for flows with nonconductive and nonmagnetic particles coincides with experimental and modelling results obtained by other explorers for flows with air bubbles. Magnetic particles with high electric conductivity are especially dangerous. Extra measurement error in this case greatly depends on the shape of the particle. Measurement error increases if particle shape differs from a sphere. The complementary measurement error can exceed the volume concentration of particles by ten times if the ratio between the longest and the shortest axes of ellipsoid exceeds 3.

This article examines the challenges and solutions related to Frequency Deviation (FD) in Continental Europe's electric power systems, focusing on the effectiveness of Combined Cycle Power Blocks (CCPB) in managing these deviations. Already since 2023, persistent and significant FD's have been a concern, leading to the establishment of a working group by the ENTSO-E System Operation Committee to develop a robust action plan. The study highlights the necessity of employing advanced control strategies in CCPB to enhance frequency quality and ensure stable system operation. It delves into the mechanisms of Automatic Generation Control (AGC) to maintain power balance and frequency stability through primary and secondary controls. These controls are critical in adapting to real-time changes in load and generation, thereby securing the power system's reliability and efficiency. The paper also discusses the implementation of Frequency Containment Reserves (FCR) and their role in stabilizing the frequency post-disturbances by automatically adjusting power outputs. Additionally, the research explores the integration of the Baltic States into the European Union (EU) energy market aiming for enhanced system security and reliability, after all the Baltic States achieved full synchronization with the Continental Europe Synchronous Area (CESA). The outcomes suggest that strategic enhancements in automatic control and reserve management can significantly mitigate FD impacts, contributing to the stability of large-scale interconnected power systems.

This article examines the challenges and solutions related to frequency deviation (FD) in Continental Europe’s electric power systems, focusing on the effectiveness of Combined Cycle Power Blocks (CCPBs) in managing these deviations. Since 2023, persistent and significant frequency deviations (FDs) have been a concern, leading to the establishment of a working group by the ENTSO-E System Operation Committee to develop a robust action plan. The study highlights the necessity of employing advanced control strategies in CCPB to enhance frequency quality and ensure stable system operation. It delves into the mechanisms of Automatic Generation Control (AGC) to maintain power balance and frequency stability through primary and secondary controls. These controls are critical in adapting to real-time changes in load and generation, thereby securing the power system’s reliability and efficiency. The paper also discusses the implementation of Frequency Containment Reserves (FCRs) and their role in stabilizing system frequency following disturbances by automatically adjusting power outputs. Additionally, the research explores the integration of the Baltic States into the European Union (EU) energy market, aiming for enhanced system security and reliability. After all, the Baltic States achieved full synchronization with the Continental Europe Synchronous Area (CESA). The outcomes confirm the suitability of the investigated CCPB for participation in AGC and FCR services under interconnected system operation.

This paper presents a comprehensive analysis of the Load Frequency Control (LFC) framework required for the synchronization of Electric Power Systems (EPSs) with Continental Europe (CE). The study focuses on ensuring stable and reliable operation of autonomously functioning EPSs by examining technical requirements and prequalification procedures for Frequency Containment Reserve (FCR) and LFC-related reserves. Numerical simulations were performed to assess system dynamic behavior under disturbance conditions. The results indicate that following a 100 MW active power loss, system frequency decreased to 49.82 Hz and was restored to the nominal 50 Hz within 9 min using FCR and automatic Frequency Restoration Reserve (aFRR). A more severe 200 MW disturbance resulted in a minimum frequency of 49.68 Hz, requiring additional activation of manual Frequency Restoration Reserve (mFRR), with recovery achieved in 18 minutes. In extreme scenarios involving up to 600 MW power loss, the frequency dropped below the critical threshold of 49.2 Hz, but full restoration was achieved within 36 min through coordinated activation of FCR, aFRR, mFRR, and Replacement Reserve (RR). Long-term simulations demonstrated that the Frequency Restoration Control Error (FRCE) remained within the System Operation Guidelines (SOGL) Level 1 limit for 75% of the time and within the stricter Level 2 limit for 96%, meeting CE quality requirements. The study also evaluates prequalification procedures, including technical testing, communication validation, and energy management for Limited Energy Reservoir providers, ensuring robust and non-discriminatory participation in balancing markets.