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All conventional techniques for measuring frequency result in large deviations to the perceived or calculated frequency when the AC waveform undergoes a phase step. The deviation magnitude and duration are dependent on the phase step magnitude, and the applied windowing/filtering. Such phase steps do occur in the power system, and the erroneous frequency calculation can result in inappropriate reactions...
In a fast changing electrical power sector the design of ancillary services is challenged and policy makers are required to take decisions on the adjustment of current ancillary services practices and on the introduction of new ancillary services. Even though ancillary services are crucial for the reliability of unbundled power systems, current literature does not provide a structured approach to...
This paper presents the validation of a rule-based control strategy trying to maximize the self-consumption of PV-converted power and providing frequency containment reserve power at the same time with a battery energy storage system placed in a residential household with roof-top PV-plant. The single model of a residential household is integrated in a simulation model of a virtual battery energy...
This paper presents the development and performance evaluation of a new controller for permanent magnet generator (PMG)-based wind energy conversion systems (WECSs) that are equipped with battery storage units. The proposed controller is developed to ensure the voltage and frequency stability under changes in the grid demands for active and reactive powers, and under under variations in the wind speed...
This paper describes scenarios proposed for a control room decision support system aimed at future power network operators. The purpose is to consider the requirements of the future control room from the perspective of the operator under the conditions of a significant frequency excursion incident. The control room visualisation and decision support functionality for aiding the operator in restoring...
In this paper, economic simulations of virtual power plants participating on the Swiss balancing market are performed and discussed. The simulations are performed by creating a generic simulation model for balancing markets which account for functions such as bidding, market clearing, delivery of control energy, and others. Several simulations allowed to estimate the opportunity from both the capacity...
As microgrid installations are steadily growing in the United States and around the world, widespread adoption of commercial microgrids would rely upon the economic benefit to the owners and operators. With the introduction of new market mechanisms and growing penetration of non-traditional generation assets, there is an increasing need and interest in allowing distributed assets to participate in...
Demand-side frequency control can complement traditional generator controls to maintain the stability of large electric systems in the face of rising uncertainty and variability associated with renewable energy resources. This paper presents a hierarchical frequency-based load control strategy that uses a supervisor to flexibly adjust control gains that a population of end-use loads respond to in...
This paper discusses the determination of a target level for an area control error ACE that is used for the evaluation of a load frequency control (LFC) performance. According to the new ENTSO-E's network code on LFC a statistic model should be used which assumes random and normally distributed averaged ACE and frequency deviation. However this is not experienced in practice. Modifications are proposed...
In this paper an optimal controller based on Action Dependent Heuristic Dynamic Programming (ADHDP) has been proposed for interconnected Automatic Generation Control (AGC) scheme. ADHDP is a powerful technique of Approximate Dynamic Programming, used for providing optimal solution by minimizing the given objective function. Two area thermal systems with non-reheat turbine have been considered in this...
Frequency control from the demand side presents a novel and viable way to complement control by traditional generators. This paper presents practical guidelines for system operators to select gain settings for a proposed frequency-based load control strategy. Simulation tests in a large interconnected system model demonstrate the robustness to different values of control gains, and sensitivities to...
The use of multi-terminal HVDC grids is a promising option to tackle the coming challenges in long distance power transmission, but the combined operation of HVDC and AC grids will bring certain challenges. The dynamic interaction from the fast controllable converter station with the rotational inertia dependent AC grids has to be investigated in detail, as well as how the converter stations will...
Thermal loads such as refrigerators and electric space heaters use temperature hysteresis controllers that are insensitive to small temperature fluctuations. This results in an ability to modulate their power consumption, thus providing cost-effective frequency support, balancing services and energy arbitrage. In order to partially realise these benefits, ENTSO-E has proposed a mandatory frequency...
In this paper an optimal controller based on Action Dependent Heuristic Dynamic Programming (ADHDP) approach has been proposed for multi area Automatic Generation Control (AGC) scheme. A competitive environment has been considered in the interconnected power system. Conventional AGC model has been modified to include bilateral transactions taking place in the energy market. To implement the ADHDP...
A systematic procedure for design of variable structure model following load frequency controller for a single{area power system has been presented. The variable structure model following control (VSMFC) technique presented in this paper not only guarantees invariance to a class of parameter variations and disturbances but also possess other attractive features of variable structure systems (VSS)...
Nowadays conventional power plants connected to the transmission system provide instantaneous reserve with energy stored in the rotating masses. In the future, many conventional power plants will be replaced by generation based on renewable energy sources in situations with strong wind and solar irradiation. Based on a load-frequency-control model and a sophisticated scenario of generation and load...
Maintaining power system frequency at constant value is very important for the health of the power generating equipment and the utilization equipment at the customer end. The job of automatic frequency regulation is achieved by governing systems of individual turbine-generators and Automatic Generation Control (AGC) or Load frequency control (LFC) system of the power system. The main objective of...
Currently in the power supply system, a large number of decentralized energy conversion systems (ECSs) based on renewable energy sources (RESs) and intelligent infrastructures are installed into the conventional power systems in order to build up “Smart Grid”. These leads, the power systems have to be carefully clarified and managed for grid integration. The control strategy and management concept...
This paper presents a new concept for power flow control by distributed UPFC. The system, called distributed power flow controller (DPFC), consists of several low-power series converters and one shunt large-power converter without common dc link. Also new is that the power exchange between the shunt and series parts is through the existing transmission line at a harmonic frequency. This solution enables...
Hawaii Electric Light operates an autonomous power system on the island of Hawaii with a diverse mix of generating resources. Although the system is small, with an annual peak in 2009 of less than 200 MW, the power system balancing and frequency control is provided through a conventional centralized Automatic Generation Control system. The mix of generation resources on the Hawaii Electric Light System...
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