scholarly journals An overview of Ancillary Services and HVDC systems in European Context

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3481 ◽  
Author(s):  
Abhimanyu Kaushal ◽  
Dirk Van Hertem
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electricity Markets ◽  
Power Transmission ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
Cost Effective ◽  
Transmission System ◽  
Ancillary Services ◽  
Market Practices

Liberalization of electricity markets has brought focus on the optimal use of generation and transmission infrastructure. In such a scenario, where the power transmission systems are being operated closer to their critical limits, Ancillary Services (AS) play an important role in ensuring secure and cost-effective operation of power systems. Emerging converter-based HVDC technologies and integration of renewable energy sources (RES) have changed the power system dynamics which are based on classical power plant operation and synchronous generator dynamics. Transmission system interconnections between different countries and integrated energy markets in Europe have led to a reduction in the use of energy from non-renewable fossil-based sources. This review paper gives an insight into ancillary services definitions and market practices for procurement and activation of these ancillary services in different control areas within the European Network of Transmission System Operators for Electricity (ENTSO-E). The focus lies particularly on ancillary services from HVDC systems. It is foreseen that DC elements will play an important role in the control and management of the future power system and in particular through ancillary services provision. Keeping this in view, the capability of HVDC systems to provide ancillary services is presented.

Parametric Modeling and Optimal Control of a Combined Heating and Power System With Energy Storage

2020 ◽  
Author(s):  
Claudia Lucia De Pascalis ◽  
Stephanie Stockar
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Power System ◽  
Energy Management ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Parametric Modeling ◽  
Medium Size ◽  
Energy Management Strategy ◽  
Generation Cost

Abstract Cogeneration is a well-known and cost effective solution for generating power and heat within the same plant, leading to improved overall efficiency and reduced generation cost. Combined heating and power systems can facilitate the penetration of renewable energy sources in medium size applications through the integration of electric and thermal energy storage units. Due to the complexity of the plant as well as significantly variability in power demand and generation, the design and operation of such systems requires a systematic co-optimization of plant and controller for guaranteeing near optimal performance. In this scenario, this paper presents a physics-based parametric modeling approach for the characterization of the main components of a 1MW combined heating and power system that includes renewable sources, electric and thermal storage devices. To demonstrate the model flexibility and potential benefits achieved by an optimal sizing, the system energy management is optimized using Dynamic Programming. The operational costs for different configurations are compared showing that an optimization of the energy management strategy in conjunction with an improved system sizing lead to more than 6% of reduction in the operational cost.

scholarly journals Operational Planning and Bidding for District Heating Systems with Uncertain Renewable Energy Production

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3310 ◽  
Author(s):  
Ignacio Blanco ◽  
Daniela Guericke ◽  
Anders Andersen ◽  
Henrik Madsen
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Electricity Markets ◽  
Electricity Market ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Operational Planning ◽  
Solution Approach ◽  
The Impact

In countries with an extended use of district heating (DH), the integrated operation of DH and power systems can increase the flexibility of the power system, achieving a higher integration of renewable energy sources (RES). DH operators can not only provide flexibility to the power system by acting on the electricity market, but also profit from the situation to lower the overall system cost. However, the operational planning and bidding includes several uncertain components at the time of planning: electricity prices as well as heat and power production from RES. In this publication, we propose a planning method based on stochastic programming that supports DH operators by scheduling the production and creating bids for the day-ahead and balancing electricity markets. We apply our solution approach to a real case study in Denmark and perform an extensive analysis of the production and trading behavior of the DH system. The analysis provides insights on system costs, how DH system can provide regulating power, and the impact of RES on the planning.

Synthesizing a Power System Stabilizer Using the Fuzzy Logic and Neural Network Methods

2021 ◽  
pp. 22-30
Author(s):  
Kahramon R. ALLAEV ◽  
◽  
Tokhir F. MAKHMUDOV ◽  
Keyword(s):  
Neural Network ◽  
Fuzzy Logic ◽  
Power Systems ◽  
Power System ◽  
Fuzzy Logic Controller ◽  
Power Transmission ◽  
Low Frequency ◽  
Synchronous Generator ◽  
Electromechanical Oscillations ◽  
The Stability

Power systems are large non-linear systems that are often subject to low frequency electromechanical oscillations with a frequency of 0.5–2.5 Hz. Power system stabilizers (PSS) are commonly used as effective and economically efficient means to dampen electromechanical oscillations of generators and increase the stability of power systems. PSS can increase the power transmission stability limits by adding a stabilizing signal through the channels of the automatic excitation control system. The article presents the results of training a neural network based on which a fuzzy logic PSS is obtained for increasing the stability of electric power systems. The synchronous generator rotor speed deviation and acceleration were taken as input data for the fuzzy logic controller. These variables have a significant effect on damping the rotor's electromechanical oscillations. The characteristics of the power system equipped with the proposed fuzzy logic based PSS are compared with its characteristics with a PSS with non-optimized parameters and without a PSS.

scholarly journals Contingency Analysis of Fault and Minimization of Power System Outage using Fuzzy Controller

2019 ◽  
Vol 9 (1) ◽  
pp. 4111-4115
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Line ◽  
Power Flow ◽  
Power Transmission ◽  
Fuzzy Controller ◽  
Transmission System ◽  
Load Flow ◽  
Contingency Analysis ◽  
Additional Advantage

In power systems, voltage stability perform the major role in design and its operation. Major system failures are occur due to voltage variability and breakdown. To meet and compensate the rising power demand of regular usage in modern trends, transmission networks are enormously loaded which create the voltage instability. Contingency analysis is a recognized energy managing tool. It calculate the violation in the transmission line. In this paper a computational controller fuzzy system is suggested to handle the transmission line outage and overload in other branch kind of problems in Power system. The efficiency of power transmission system with fuzzy controller is inveterate by computation of various parameters of transmission bus under different loading situations. For the contingency analysis the transmission power flow several methods have been developed. Fast Decoupled load flow program is the effective method which provides a fast and effective solution to the contingency analysis in the transmission system and also it is incorporate with matrix alteration formula which gives additional advantage for the system.

scholarly journals Ancillary Services Market Design in Distribution Networks: Review and Identification of Barriers

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 917 ◽  
Author(s):  
Konstantinos Oureilidis ◽  
Kyriaki-Nefeli Malamaki ◽  
Konstantinos Gallos ◽  
Achilleas Tsitsimelis ◽  
Christos Dikaiakos ◽  
...  
Keyword(s):  
Electricity Markets ◽  
Renewable Energy Sources ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Transmission System ◽  
Ancillary Services ◽  
Distribution Grid ◽  
Specific System ◽  
Support Functions ◽  
Grid Level

The high proliferation of converter-dominated Distributed Renewable Energy Sources (DRESs) at the distribution grid level has gradually replaced the conventional synchronous generators (SGs) of the transmission system, resulting in emerging stability and security challenges. The inherent characteristics of the SGs are currently used for providing ancillary services (ASs), following the instructions of the Transmission System Operator, while the DRESs are obliged to offer specific system support functions, without being remunerated for these functions, but only for the energy they inject. This changing environment has prompted the integration of energy storage systems as a solution for transfusing new characteristics and elaborating their business in the electricity markets, while the smart grid infrastructure and the upcoming microgrid architectures contribute to the transformation of the distribution grid. This review investigates the existing ASs in transmission system with the respective markets (emphasizing the DRESs’ participation in these markets) and proposes new ASs at distribution grid level, with emphasis to inertial response, active power ramp rate control, frequency response, voltage regulation, fault contribution and harmonic mitigation. The market tools and mechanisms for the procurement of these ASs are presented evolving the existing role of the Operators. Finally, potential barriers in the technical, regulatory, and financial framework have been identified and analyzed.

scholarly journals Comparison of Virtual Synchronous Generator Strategies for Control of Distributed Energy Sources and Power System Stability Improvement

2021 ◽  
Author(s):  
Guilherme Penha da Silva Júnior ◽  
Thiago Figueiredo do Nascimento ◽  
Luciano Sales Barros
Keyword(s):  
Power Systems ◽  
Power System ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
System Stability ◽  
Control Mode ◽  
Voltage Source ◽  
Energy Sources ◽  
And Performance ◽  
Virtual Synchronous Generator

The high integration of distributed generation (DG) system based on renewable energy sources (RES) in the power system requires changes regarding the control mode of these sources with some urgency. Such changes seek to maintain the stability of the power systems. Thus, there is a demand for using control techniques on DGs/RESs that can mitigate the disturbances caused by low inertia and the lack of control over the dispatched powers. As a solution, one can use virtual synchronous generator (VSG) techniques making the voltage  source inverter (VSI) control behave similarly to the traditional synchronous generator (SG). This paper presents a literature review and performance tests for the main VSG topologies used in DGs/RESs: ISE, VSYNC, VISMA and Synchronverter. The implementation of VSG in the DGs/RESs has made possible increase inertia in the grid and, additionally regulate the active and reactive powers separately and bidirectionally. So, it has been possible to meet power system requirements; being able to operation both grid-connected or island-mode, which is ideal for microgrids. The results obtained confirm the literature reports. It was observed that the Synchronverter topology presented advantages over the other VSG topologies.

scholarly journals Frequency Support Markets and Wind Power Integration

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7450
Author(s):  
Anzhelika Ivanova ◽  
José Luis Domínguez-García ◽  
Cristina Corchero
Keyword(s):  
Wind Power ◽  
Electricity Markets ◽  
Power Plants ◽  
Economic Benefits ◽  
Ancillary Services ◽  
Renewable Sources ◽  
Wind Generators ◽  
Wind Power Plants ◽  
Market Practices ◽  
System Benefit

Europe’s initiative to reduce the emissions of harmful gases has significantly increased the integration of renewable sources into power networks, particularly wind power. Variable renewable sources pose challenges to sustain the balance between generation and demand. Thus, the need for ancillary services to cope with this problem has increased. In this regard, the integration of larger shares of wind generation would have a clear system benefit when wind generators are able to provide these ancillary services. This would also have implications for electricity markets, enabling these services from wind power plants. This article gives an overview of several European markets for frequency support (FS) services, also referred to as FS markets. It identifies the changes in national regulations of 10 European countries to standardize these services based on the ENTSO-E guidelines. However, most of the countries still use their national service definitions, which presents a problem for researchers to understand the national regulations in relation to the ENTSO-E guidelines. This article provides a classification of the national FS services under the definitions of the ENTSO-E guidelines to facilitate research on this topic. Furthermore, it highlights the main requirements for the market practices that would encourage the participation of wind power generation in the provision of these services. An estimation of the economic benefits for wind producers from the provision of FS services is provided as well to show a possible outcome if changes are not made in national policies.

scholarly journals Dynamic Analysis for VSG-Based Power Flow Control Applied to DG Systems

2021 ◽  
Author(s):  
THIAGO FIGUEIREDO DO NASCIMENTO ◽  
ANDRES ORTIZ SALAZAR
Keyword(s):  
Power Systems ◽  
Dynamic Analysis ◽  
Power Flow ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Dynamic Performance ◽  
Synchronous Generator ◽  
Power Flow Control ◽  
Grid Impedance ◽  
Impedance Parameters

The integration of distributed generation (DG) systems based on renewable energy sources (RES) by using power converters is an emerging technology in modern power systems. Among the control strategies applied to this new configuration, the virtual synchronous generator (VSG) approach has proven to be an attractive solution due providing suitable dynamic performance. Thus, this paper presents a dynamic analysis of gridtied converters controlled by using VSG concept. This analysis is based on a dynamic model that describes the DG power flow transient characteristics. Based on this model, the grid impedance parameters variation effects on the VSG controllers dynamic performance are discussed. Simulation results are presented to evaluate the effectiveness of the theoretical analysis performed.

scholarly journals Operating Performance of Power Systems Integrated HVDC Solution: KonTum-GiaLai Transmission System Case Considering Penetration of Renewable Energy

2020 ◽  
Vol 18 (4.2) ◽  
pp. 32
Author(s):  
Kim Hung Le ◽  
Ngoc Thien Nam Tran ◽  
Viet Tri Nguyen ◽  
The Khanh Truong ◽  
Minh Quan Duong
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
High Voltage ◽  
Short Circuit ◽  
Renewable Energy Sources ◽  
Transmission Efficiency ◽  
Transmission System ◽  
Large Power ◽  
Hvdc System ◽  
Hvdc Transmission

The increasing demand for electricity along with the development of distributed generators showed that improving transmission efficiency and reliability is an indispensable requirement in the operation of the power system. Advanced technologies need to be applied to modern power systems for purposes of conveying large power flows, mitigating the risk of faults. High-voltage direct current (HVDC) transmission is now considered an effective solution for investment in large-length power lines, replacing the conventional high-voltage alternative current (HVAC) transmission system, especially in period of increasing generation capacity due to the penetration of renewable energy sources. This study assesses the performance of the HVDC system on an actual power grid based on planning and improvement demands. The calculation results of power flows, power losses and short-circuit faults were investigated using ETAP software X  

scholarly journals A Review of Virtual Inertia Techniques for Renewable Energy-Based Generators

2020 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Emilio Gómez-Lázaro ◽  
Eduard Muljadi ◽  
Ángel Molina-Garcia
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Plants ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Extensive Discussion ◽  
Renewable Sources ◽  
Virtual Inertia ◽  
Alternative Sources

Over recent decades, the penetration of renewable energy sources (RES), especially photovoltaic and wind power plants, has been promoted in most countries. However, as these both alternative sources have power electronics at the grid interface (inverters), they are electrically decoupled from the grid. Subsequently, stability and reliability of power systems are compromised. Inertia in power systems has been traditionally determined by considering all the rotating masses directly connected to the grid. Thus, as the penetration of renewable units increases, the inertia of the power system decreases due to the reduction of directly connected rotating machines. As a consequence, power systems require a new set of strategies to include these renewable sources. In fact, ‘hidden inertia,’ ‘synthetic inertia’ and ‘virtual inertia’ are terms currently used to represent an artificial inertia created by inverter control strategies of such renewable sources. This chapter reviews the inertia concept and proposes a method to estimate the rotational inertia in different parts of the world. In addition, an extensive discussion on wind and photovoltaic power plants and their contribution to inertia and power system stability is presented.

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