scholarly journals Dual Frequency Regulation in Pumping Mode in a Wind–Hydro Isolated System

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2865 ◽  
Author(s):  
José Sarasúa ◽  
Guillermo Martínez-Lucas ◽  
Carlos Platero ◽  
José Sánchez-Fernández
Keyword(s):  
Power Systems ◽  
Power System ◽  
Frequency Control ◽  
Hydropower Plant ◽  
Frequency Regulation ◽  
Variable Speed ◽  
Dual Frequency ◽  
Pump Station ◽  
Control Scheme ◽  
Pumped Storage

Frequency control is one of the most critical tasks in isolated power systems, especially in high renewable penetration scenarios. This paper presents a new hydropower pumped-storage dual control strategy that combines variable-speed-driven pumps and fixed-speed-driven pumps. A possible case for implementation of such a control scheme is described based on El Hierro Island’s power system. This isolated power system consists of a hybrid wind pumped-storage hydropower plant and diesel generators. The pumped-storage power plant is divided into a hydropower plant equipped with four Pelton turbines and a pump station equipped with both fixed- and variable-speed pumps. According to the proposed control scheme, frequency regulation will be provided by a dual controller: a continuous controller for the variable-speed pumps and a discrete controller for the fixed-speed pumps. The Pelton units, which operate as synchronous condensers, also supply the power system inertia. Therefore, diesel units may be disconnected, decreasing generation costs and greenhouse gas emissions. Owing to the combination of both controllers and the inertia of the Pelton units, an acceptable frequency regulation can be achieved. This technique has been validated through computer simulations.

scholarly journals Analysis of the Implementation of the Primary and/or Inertial Frequency Control in Variable Speed Wind Turbines in an Isolated Power System with High Renewable Penetration. Case Study: El Hierro Power System

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 901 ◽  
Author(s):  
Guillermo Martínez-Lucas ◽  
José Ignacio Sarasúa ◽  
Juan Ignacio Pérez-Díaz ◽  
Sergio Martínez ◽  
Danny Ochoa
Keyword(s):  
Wind Speed ◽  
Power Systems ◽  
Power System ◽  
Wind Turbines ◽  
Wind Farm ◽  
Frequency Control ◽  
Frequency Regulation ◽  
Variable Speed ◽  
El Hierro

With high levels of wind energy penetration, the frequency response of isolated power systems is more likely to be affected in the event of a sudden frequency disturbance or fluctuating wind conditions. In order to minimize excessive frequency deviations, several techniques and control strategies involving Variable Speed Wind Turbines (VSWTs) have been investigated in isolated power systems. In this paper, the main benefits and disadvantages of introducing VSWTs—both their inertial contribution and primary frequency regulation—in an exclusively renewable isolated power system have been analyzed. Special attention has been paid to the influence of the delays of control signals in the wind farm when VSWTs provide primary regulation as well as to the wind power reserve value which is needed. To achieve this objective, a methodology has been proposed and applied to a case study: El Hierro power system. A mathematical dynamic model of the isolated power system, including exclusively renewable technologies, has been described. Representative generation schedules and wind speed signals have been fixed according to the observed system. Finally, in order to obtain conclusions, realistic system events such as fluctuations in wind speed and the outage of the generation unit with the higher assigned power in the power system have been simulated.

scholarly journals Simplified Model for Evaluation of Hydropower Plant Conversion into Pumped Storage Hydropower Plant

2021 ◽  
Vol 58 (3) ◽  
pp. 108-120
Author(s):  
S. Kiene ◽  
O. Linkevics
Keyword(s):  
Power Systems ◽  
Price Volatility ◽  
Hydropower Plant ◽  
Simplified Model ◽  
Plant Conversion ◽  
Power Exchange ◽  
Pump Station ◽  
Pumped Storage ◽  
Storage Technologies

Abstract Increasing capacity of intermittent generation brings new challenges to balance demand and supply in power systems. With retirement of conventional fossil generation, the role of energy storage is increasing. One of the most competitive storage technologies is pumped storage hydropower plant (PSHP). Usually, such PSHPs are constructed as green field solutions, but in some cases conversion of a hydropower plant into a pump storage hydropower plant by building a pump station is possible. To evaluate the feasibility of such modernisation it is necessary to estimate the benefits of PSHP operation. The simplified model was developed for simulation of charging and discharging cycles of PSHP in Latvian power system and trading electricity in Nord Pool power exchange. The nature of this task is stochastic as the price volatility has a trend to increase with expansion of wind and solar power plant capacity. Results of PSHP operation simulation were then used in the economic model to evaluate the feasibility of the proposed conversion.

Study on the Influence of DFIG Units with Additional Frequency Control on Power System Emergency Control

2012 ◽  
Vol 608-609 ◽  
pp. 579-583
Author(s):  
Yao Fei Hou ◽  
Guang Kai Li ◽  
Jian Ding ◽  
Jie Shen ◽  
Song Teng
Keyword(s):  
Power System ◽  
Wind Turbines ◽  
Frequency Control ◽  
Control Measures ◽  
Frequency Regulation ◽  
Variable Speed ◽  
Large Power ◽  
Emergency Control ◽  
Doubly Fed ◽  
System Frequency

The variable-speed doubly-fed wind turbines (DFIG) were able to participate in frequency regulation by adding an additional frequency control. The influences exerted by the additional frequency control of DFIG units and conventional units governors on system frequency emergency control measures were analyzed. When the power shortage is small, it is recommended to consider the DFIG units to participate in frequency regulation, While a large power shortage it is not recommended.

scholarly journals On the possibility of participation of npps with vverin emergency frequency regulation in power system

2019 ◽  
Vol 21 (3) ◽  
pp. 99-108
Author(s):  
V. A. Khrustalev ◽  
M. V. Garievskii ◽  
I. A. Rostuntsova ◽  
A. V. Portyankin
Keyword(s):  
Power Systems ◽  
Power System ◽  
Nuclear Power ◽  
Power Plants ◽  
Frequency Control ◽  
Reactor Core ◽  
Operating Conditions ◽  
Frequency Regulation ◽  
Primary Control ◽  
Main Circulation

The purpose of the article is to study the possibility and feasibility of participation of nuclear power plants (NPPs) with VVER in emergency frequency control in power systems with a high proportion of nuclear power units and, at the same time, of reducing the power consumption for the own needs of the main circulation pumps during modes with power below nominal. To solve these problems, it was proposed to increase the achievable speeds of power gain (load increase) due to the installation of frequency controlled drives of the MCP. Large system frequency variations (caused by large imbalances between generation and demand) may jeopardize electrical equipment, in terms of maintaining stable and reliable operating conditions. For NPPs, the task of preventing or localizing accidents is even more important than for TPPs, since in case of major system accidents, it is possible to completely stop external power supply of the NPPs own needs. Thus, besides the requirements for the primary control of the frequency of NPPs with VVER, today we need more stringent requirements for their emergency acceleration and mobility. The operation of NPPs with long-term non-recoverable active power shortage causes a decrease in the speed of the main circulation pumps of NPPs with VVER and a decrease in the coolant flow rate. It is shown that the installation of variable frequency drives of the MCPs at NPP with VVER is appropriate not only to save energy consumption for their drive in partial modes, but also to increase the power of NPP above the nominal (without reducing the reserve before the heat exchange crisis in the reactor core) for the elimination of system accidents, and thus to improve the safety of the NPPs included in the power system.

scholarly journals Prospects of Storage and Pumped-Storage Hydropower for Enhancing Integrated Nepal Power Systems

2014 ◽  
Vol 15 ◽  
pp. 37-41 ◽  
Author(s):  
Neeraj Kumar Sah ◽  
Madhab Uprety ◽  
Sangharsha Bhandari ◽  
Prativa Kharel ◽  
Saurav Suman ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Plants ◽  
Peak Load ◽  
Electrical Energy ◽  
Hydropower Plant ◽  
Hydropower Plants ◽  
Pumped Storage ◽  
Electrical Demand ◽  
Installed Capacity

An Integrated Power System (IPS) should have electrical energy generating plants for base load (e.g., nuclear and thermal plants) and peak load (e.g., hydropower plants) so that they can work in coordination in such a way that the demand is met in time. In Nepal, the Integrated Nepal Power System (INPS) is a hydro-dominated system where the base and intermediate power demands are covered primarily by run-of-river hydropower plants and the peak demand by seasonal storage and several diesel power plants of lower capacity. The INPS should have sufficient natural storage and forced storage power plants to improve the system’s reliability. On top of that, daily peak electrical demand could also be adequately covered by demand-side management, using a pumped-storage hydropower plant that can employ a system’s surplus energy during low demand period for pumping. To rectify this extreme imbalance of installed capacity in Nepal, this paper explores the prospect of storage and pumped-storage power plants for enhancing INPS. A case study of Rupa-Begnas pumped-storage hydropower is highlighted for these purposes.DOI: http://dx.doi.org/10.3126/hn.v15i0.11290HYDRO Nepal JournalJournal of Water, Energy and EnvironmentVolume: 15, 2014, JulyPage: 37-41 

scholarly journals Application of Battery Energy Storage Systems for Primary Frequency Control in Power Systems with High Renewable Energy Penetration

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1379
Author(s):  
Md Ruhul Amin ◽  
Michael Negnevitsky ◽  
Evan Franklin ◽  
Kazi Saiful Alam ◽  
Seyed Behzad Naderi
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Storage Systems ◽  
Frequency Control ◽  
Battery Energy Storage ◽  
Battery Energy Storage Systems ◽  
Battery Energy ◽  
Primary Frequency ◽  
Primary Frequency Control

In power systems, high renewable energy penetration generally results in conventional synchronous generators being displaced. Hence, the power system inertia reduces, thus causing a larger frequency deviation when an imbalance between load and generation occurs, and thus potential system instability. The problem associated with this increase in the system’s dynamic response can be addressed by various means, for example, flywheels, supercapacitors, and battery energy storage systems (BESSs). This paper investigates the application of BESSs for primary frequency control in power systems with very high penetration of renewable energy, and consequently, low levels of synchronous generation. By re-creating a major Australian power system separation event and then subsequently simulating the event under low inertia conditions but with BESSs providing frequency support, it has been demonstrated that a droop-controlled BESS can greatly improve frequency response, producing both faster reaction and smaller frequency deviation. Furthermore, it is shown via detailed investigation how factors such as available battery capacity and droop coefficient impact the system frequency response characteristics, providing guidance on how best to mitigate the impact of future synchronous generator retirements. It is intended that this analysis could be beneficial in determining the optimal BESS capacity and droop value to manage the potential frequency stability risks for a future power system with high renewable energy penetrations.

scholarly journals 5G Poor and Rich Novel Control Scheme Based Load Frequency Regulation of a Two-Area System with 100% Renewables in Africa

2020 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Hady H. Fayek
Keyword(s):  
Power System ◽  
Fractional Order ◽  
Packet Loss ◽  
Pid Controller ◽  
Frequency Control ◽  
Operating Conditions ◽  
Load Frequency Control ◽  
Load Frequency ◽  
Control Scheme ◽  
Non Linear

Remote farms in Africa are cultivated lands planned for 100% sustainable energy and organic agriculture in the future. This paper presents the load frequency control of a two-area power system feeding those farms. The power system is supplied by renewable technologies and storage facilities only which are photovoltaics, biogas, biodiesel, solar thermal, battery storage and flywheel storage systems. Each of those facilities has 150-kW capacity. This paper presents a model for each renewable energy technology and energy storage facility. The frequency is controlled by using a novel non-linear fractional order proportional integral derivative control scheme (NFOPID). The novel scheme is compared to a non-linear PID controller (NPID), fractional order PID controller (FOPID), and conventional PID. The effect of the different degradation factors related to the communication infrastructure, such as the time delay and packet loss, are modeled and simulated to assess the controlled system performance. A new cost function is presented in this research. The four controllers are tuned by novel poor and rich optimization (PRO) algorithm at different operating conditions. PRO controller design is compared to other state of the art techniques in this paper. The results show that the PRO design for a novel NFOPID controller has a promising future in load frequency control considering communication delays and packet loss. The simulation and optimization are applied on MATLAB/SIMULINK 2017a environment.

Frequency and inertia response effects, capabilities, and possibilities in renewable energy sources

2021 ◽  
Vol 14 ◽  
Author(s):  
Jishu Mary Gomez ◽  
Prabhakar Karthikeyan Shanmugam
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Energy Systems ◽  
Load Shedding ◽  
System Stability ◽  
Frequency Regulation ◽  
Control Schemes ◽  
Inertia Response

Background & Objectives: The global power system is in a state of continuous evolution, incorporating more and more renewable energy systems. The converter-based systems are void of inherent inertia control behavior and are unable to curb minor frequency deviations. The traditional power system, on the other hand, is made up majorly of synchronous generators that have their inertia and governor response for frequency control. For improved inertial and primary frequency response, the existing frequency control methods need to be modified and an additional power reserve is to be maintained mandatorily for this purpose. Energy self-sufficient renewable distributed generator systems can be made possible through optimum active power control techniques. Also, when major global blackouts were analyzed for causes, solutions, and precautions, load shedding techniques were found to be a useful tool to prevent frequency collapse due to power imbalances. The pre-existing load shedding techniques were designed for traditional power systems and were tuned to eliminate low inertia generators as the first step to system stability restoration. To incorporate emerging energy possibilities, the changes in the mixed power system must be addressed and new frequency control capabilities of these systems must be researched. Discussion: In this paper, the power reserve control schemes that enable frequency regulation in the widely incorporated solar photovoltaic and wind turbine generating systems are discussed. Techniques for Under Frequency Load Shedding (UFLS) that can be effectively implemented in renewable energy enabled micro-grid environment for frequency regulation are also briefly discussed. The paper intends to study frequency control schemes and technologies that promote the development of self- sustaining micro-grids. Conclusion: The area of renewable energy research is fast emerging with immense scope for future developments. The comprehensive literature study confirms the possibilities of frequency and inertia response enhancement through optimum energy conservation and control of distributed energy systems.

scholarly journals On the Contribution of Wind Farms in Automatic Generation Control: Review and New Control Approach

2018 ◽  
Vol 8 (10) ◽  
pp. 1848 ◽  
Author(s):  
Arman Oshnoei ◽  
Rahmat Khezri ◽  
SM Muyeen ◽  
Frede Blaabjerg
Keyword(s):  
Power System ◽  
Wind Turbine ◽  
Frequency Control ◽  
Wind Farms ◽  
Automatic Generation ◽  
Load Frequency Control ◽  
Automatic Generation Control ◽  
Frequency Regulation ◽  
Proportional Integral ◽  
Generation Control

Wind farms can contribute to ancillary services to the power system, by advancing and adopting new control techniques in existing, and also in new, wind turbine generator systems. One of the most important aspects of ancillary service related to wind farms is frequency regulation, which is partitioned into inertial response, primary control, and supplementary control or automatic generation control (AGC). The contribution of wind farms for the first two is well addressed in literature; however, the AGC and its associated controls require more attention. In this paper, in the first step, the contribution of wind farms in supplementary/load frequency control of AGC is overviewed. As second step, a fractional order proportional-integral-differential (FOPID) controller is proposed to control the governor speed of wind turbine to contribute to the AGC. The performance of FOPID controller is compared with classic proportional-integral-differential (PID) controller, to demonstrate the efficacy of the proposed control method in the frequency regulation of a two-area power system. Furthermore, the effect of penetration level of wind farms on the load frequency control is analyzed.

Sign in / Sign up

Export Citation Format

Share Document