Provision of Ancillary Services with Variable Speed Wind Turbines

In recent years, the amount of wind turbines in the power system has increased tremendously. As the current wind turbines do not participate in the provision of ancillary services such as frequency control and voltage control, this may compromise the proper functioning of the electric power system. However, since the modern wind turbines are equipped with a power-electronic converter, they can assist in the provision of ancillary services. To achieve this, additional control loops have to be added to the wind turbine controller. In this paper, an overview of the different ancillary services is given. The ability to provide them with wind turbines is discussed. Since frequency and voltage control are the most important, these two services are further elaborated. It can be concluded that wind turbines are suited to provide frequency control, especially when they are operated slightly below their maximum power point. They can also assist in voltage control, while operation in the maximum power point is usually possible, so few energy is lost. These are important outcomes, since wind turbines which provide ancillary services can contribute in allowing a higher penetration of renewable energy in the power system without compromising its proper functioning

Optimal household energy management and participation in ancillary services with PV production

The work presented in this paper deals with a project aiming to increase the value of photovoltaic (PV) solar production for residential application. To contribute to the development of the new functionalities for such system and the efficient control system to optimize its operation, this paper defines the possibility for the proposed system to participate to the ancillary services, particularly in active power service provider. This service of PV-based system for housing application, as it does not exist today, has led to a market design proposition in the distribution system. The mathematical model for calculating the optimal operation of system (sources, load, and the exchange power with the grid) results in a linear mix integer optimization problem where the objective is to maximize the profit obtained by participating to electricity market. The approach is illustrated in an example study case. The PV producer could benefit from its intervention on balancing market or ancillary services market despite of the impact on the profit of several kinds of uncertainty, as the intermittence of PV source.energy management ; ancillary services ; PV production ; household application

Voltage control ancillary services for low voltage distributed generation

This paper sheds light on the provision of voltage control ancillary services for low voltage distributed generation, DG, the need for the creation of the microgrid ancillary services market, since the ancillary service network operation does not include small size energy generation. The limitations facing the participation of DG in the provision of ancillary services, the basis for the creation of a microgrid ancillary service market, the gap between the large power plants and smaller sources, as well as useful recommendations to help proffer solution to the problem were considered. This work also embraces the types of ancillary services, microgrid, distributed generations, voltage control ancillary services, the various types of voltage control service and their usefulness to power system network. The various techniques for voltage control and the relationship between reactive power and voltage control, power factor and power factor corrections and its useful to power system was also illustrated

Efficient bidding for hydro power plants in markets for energy and ancillary services

In order to preserve stability of electricity supply generators must provide ancillary services in addition to energy production. Hydroelectric resources have significant ancillary service capability because of their dynamic flexibility. This paper suggests a solution for optimal bidding for hydro units operating in simultaneous markets for energy and ancillary services by estimating water shadow price from operating parameters of the hydro unit, expectations on prices of energy and ancillary services, and water availability. The model implications are illustrated on a numerical example of a hydro unit operating in markets of New York Independent System Operator. Participation in ancillary services market increases or decreases water shadow price depending on water availability. As a result of participation in ancillary services markets, a unit with water availability given by a capacity factor of 0.6 increases the value of existing generating capacity by 25% and nearly doubles the value of incremental generating capacity

Ancillary Services in Hybrid AC/DC Low Voltage Distribution Networks

In the last decade, distribution systems are experiencing a drastic transformation with the advent of new technologies. In fact, distribution networks are no longer passive systems, considering the current integration rates of new agents such as distributed generation, electrical vehicles and energy storage, which are greatly influencing the way these systems are operated. In addition, the intrinsic DC nature of these components, interfaced to the AC system through power electronics converters, is unlocking the possibility for new distribution topologies based on AC/DC networks. This paper analyzes the evolution of AC distribution systems, the advantages of AC/DC hybrid arrangements and the active role that the new distributed agents may play in the upcoming decarbonized paradigm by providing different ancillary services.Ministerio de Economía y Competitividad ENE2017-84813-RUnión Europea (Programa Horizonte 2020) 76409

Smart Fridge / Dumb Grid? Demand Dispatch for the Power Grid of 2020

In discussions at the 2015 HICSS meeting, it was argued that loads can provide most of the ancillary services required today and in the future. Through load-level and grid-level control design, high-quality ancillary service for the grid is obtained without impacting quality of service delivered to the consumer. This approach to grid regulation is called demand dispatch: loads are providing service continuously and automatically, without consumer interference. In this paper we ask, what intelligence is required at the grid-level? In particular, does the grid-operator require more than one-way communication to the loads? Our main conclusion: risk is not great in lower frequency ranges, e.g., PJM's RegA or BPA's balancing reserves. In particular, ancillary services from refrigerators and pool-pumps can be obtained successfully with only one-way communication. This requires intelligence at the loads, and much less intelligence at the grid level

Strategic allocation and energy management of BESS for the provision of ancillary services in active distribution networks

The increased penetration of renewables has prompted the integration of battery energy storage systems (BESSs) in active distribution networks. The BESS not only act as backup power supply but also provides various ancillary services with extra degree of flexibility to distribution networks by changing its' role as generation and load. In this study, a new optimization framework is developed to optimally allocate the intense wind power generation units and BESSs considering its ancillary services in distribution systems. The BESSs are strategically allocated at two sites in coordination with the renewable generating source. One is installed at grid substation to participate in central ancillary services whereas; second will be used to participate in distributed ancillary services. The objective is to minimize the cost of annual energy loss while performing various ancillary services in distribution network. The proposed optimization framework is implemented on a real-life 108-bus Indian distribution system for different cases and solved using genetic algorithm. The comparison of simulation results show that the proposed optimization framework provides more energy loss reduction, improved system voltage and power factor at higher penetration of wind power generation units as compared to the cases in which ancillary services are not considered in planning

Market-based Control of Air-Conditioning Loads with Switching Constraints for Providing Ancillary Services

Air-conditioning loads (ACLs) are among the most promising demand side resources for their thermal storage capacity and fast response potential. This paper adopts the principle of market-based control (MBC) for the ACLs to participate in the ancillary services. The MBC method is suitable for the control of distributed ACLs because it can satisfy diversified requirements, reduce the communication bandwidth and protect users' privacy. The modified bidding and clearing strategies proposed in this paper makes it possible to adjust the switching frequency and strictly satisfy the lockout time constraint for mechanical wear reduction and device protection, without increasing the communication traffic and computational cost of the control center. The performance of the ACL cluster in two typical ancillary services is studied to demonstrate the effect of the proposed method. The case studies also investigate how the control parameters affect the response performance, comfort level and switching frequency.Comment: 5 pages, conferenc

Risk assessment for ancillary services

The power trading and ancillary services provision comprise technical and financial risks and therefore require a structured risk management. Focus in this paper is on financial risk management that is important for the system operator faces when providing and using ancillary services for balancing of power system. Risk on ancillary services portfolio is modeled through value at risk and conditional value at risk measures. The application of these risk measures in power system is given in detail to show how to using the risk concept in practice. Conditional value at risk optimization is analysed in the context of portfolio selection and how to apply this optimization for hedging a portfolio consisting of different types of ancillary services

A Review of Ancillary Services Implementation in the Revenue Management Systems

Ancillary services in air transport represent a set of services provided to passengers to choose from, enabling them to enhance their travel experience while accumu-lating additional airline revenue. Low-cost airlines pi-oneered the practice, but the separation of ancillary services from the basic service has become an intense-ly growing trend in the air transport industry over the last decade. This practice has enabled low-cost airlines to significantly reduce the price of the basic service. To remain competitive in an era of transparency provided by search engines, traditional airlines offer ancillary ser-vices in addition to the basic service. To meet the passen-ger’s needs, a whole range of ancillary services has been created. However, existing revenue management systems do not take this ancillary revenue into account when cal-culating reservation limits. If the airline knew that an in-dividual passenger is willing to pay more for ancillary services, the system would be able to adjust the availabil-ity of the service for that passenger during the booking process. A review of research on passengers’ willingness to pay for ancillary services is presented in the paper, as well as a review on research on the personalisation of ancillary services and challenges of integrating person-alised pricing into existing revenue management systems