scholarly journals Statistical processing of wind and solar PV generation variability for assessment of additional power system flexibility

2021 ◽  
Vol 2021 (1) ◽  
pp. 14-28
Author(s):  
S.V. Shulzhenko ◽  

To solve the actual task of assessing additional flexible generation needed to smooth variable renewable energies (VRE) disturbances in the Power Systems worldwide the original method for statistical processing of wind and solar PV generation variability data was proposed in the article. The proposed method allows processing the historical data of VRE day-by-day and hour-to-hour generation and assessing the levels of potential disturbances this type of generation could cause. These disturbances should be smoothened in the Power System by others, usually conventional generators at least to ensure grid stability and electricity quality. Currently, at the stage of the power systems starts transformation, the sources of power system flexibility basically are the power plants whose individual flexibility is characterized by three dimensions: adjustability, ramping and lead time. Lack of flexible generation causes VRE curtailments that negatively affect economic efficiency of such clean generation. From the other hand, the improvement of existing power plants flexibility requires an essential investments and time to retrofit them, and because of that the important question - what is the required level of power system flexibility is needed to smooth current and future VRE generation. The results of statistical data processing for wind and solar PV hour-by-hour power output changes allow accepting the hypothesis about the normal distribution of these data sets. The article presents the key parameters of theoretical normal distributions are calculated for wind and solar PV data sets for 2019 and 2020 as a whole, and also for winter and summer seasons, which allow obtaining a more precise assessment of variability levels for renewables, especially for solar PV hour-by-hour generation changes. The assessments obtained in the article also could be used as the first step for more efficient management of the electricity market, for instance, forecasting the required level of flexible generation or ancillary services market for intraday power system balancing. Keywords: variable renewable energy, power system, flexibility, generation profile, statistical data processing

2019 ◽  
Vol 16 (2) ◽  
pp. 142 ◽  
Author(s):  
M. Albadi

Although solar photovoltaic (PV) systems are environmentally friendly, policy makers and power system operators have concerns regarding the high penetration of these systems due to potential impacts of solar power intermittency on power systems. Understanding the nature of this intermittency is important to make informed decisions regarding solar power plants, size and location, transmission and distribution systems planning, as well as thermal generation units and electricity markets operations. This article presents a review of solar PV power characteristics and its impacts on power system operation.


Author(s):  
B. Venkateswara Rao ◽  
Ramesh Devarapalli ◽  
H. Malik ◽  
Sravana Kumar Bali ◽  
Fausto Pedro García Márquez ◽  
...  

The trend of increasing demand creates a gap between generation and load in the field of electrical power systems. This is one of the significant problems for the science, where it require to add new generating units or use of novel automation technology for the better utilization of the existing generating units. The automation technology highly recommends the use of speedy and effective algorithms in optimal parameter adjustment for the system components. So newly developed nature inspired Bat Algorithm (BA) applied to discover the control parameters. In this scenario, this paper considers the minimization of real power generation cost with emission as an objective. Further, to improve the power system performance and reduction in the emission, two of the thermal plants were replaced with wind power plants. In addition, to boost the voltage profile, Static VAR Compensator (SVC) has been integrated. The proposed case study, i.e., considering wind plant and SVC with BA, is applied on the IEEE30 bus system. Due to the incorporation of wind plants into the system, the emission output is reduced, and with the application of SVC voltage profile improved.


2018 ◽  
Vol 8 (2) ◽  
pp. 2633-2639 ◽  
Author(s):  
K. Soleimani ◽  
J. Mazloum

Power systems include multiple units linked together to produce constantly moving electric power flux. Stability is very important in power systems, so controller systems should be implemented in power plants to ensure power system stability either in normal conditions or after the events of unwanted inputs and disorder. Frequency and active power control are more important regarding stability. Our effort focused on designing and implementing robust PID and PI controllers based on genetic algorithm by changing the reference of generating units for faster damping of frequency oscillations. Implementation results are examined on two-area power system in the ideally state and in the case of parameter deviation. According to the results, the proposed controllers are resistant to deviation of power system parameters and governor uncertainties.


2020 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Emilio Gómez-Lázaro ◽  
Eduard Muljadi ◽  
Ángel Molina-Garcia

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.


2020 ◽  
Vol 209 ◽  
pp. 07014
Author(s):  
Tulkin Gayibov ◽  
Bekzod Pulatov

Optimal planning of short-term modes of power systems is a complex nonlinear programming problem with many simple, functional and integral constraints in the form of equalities and inequalities. Especially, the presence of integral constraints causes significant difficulties in solving of such problem. Since, under such constraints, the modes of power system in separate time intervals of the considered planning period become dependent on the values of the parameters in other intervals. Accordingly, it becomes impossible to obtain the optimal mode plan as the results of separate optimization for individual time intervals of the period under consideration. And the simultaneous solution of the problem for all time intervals of the planning period in the conditions of large power systems is associated with additional difficulties in ensuring the reliability of convergence of the iterative computational process. In this regard, the issues of improving the methods and algorithms for optimization of short-term modes of power systems containing thermal and large hydroelectric power plants with reservoirs, in which water consumption is regulated in the short-term planning period, remains as an important task. In this paper, we propose the effective algorithm for solving the problem under consideration, which makes it possible to quickly and reliably determine the optimal operating modes of the power system for the planned period. The results of research of effectiveness of this algorithm are presented on the example of optimal planning of daily mode of the power system, which contains two thermal and three hydraulic power plants..


2011 ◽  
Vol 1 (4) ◽  
pp. 84-89
Author(s):  
E. A. Al-Ammar ◽  
N. H. Malik ◽  
M. Usman

One of the major world wide concerns of the utilities is to reduce the emissions from traditional power plants by using renewable energy and to reduce the high cost of supplying electricity to remote areas. Hybrid power systems can provide a good solution for such problems because they integrate renewable energy along with the traditional power plants. In Kingdom of Saudi Arabia a remote village called Al-Qtqt, was selected as a case study in order to investigate the ability to use a hybrid power system to provide the village with its needs of electricity. The simulation of this hybrid power system was done using HOMER software.


2021 ◽  
Vol 2021 (5) ◽  
pp. 55-62
Author(s):  
B.I. Basok ◽  
◽  
O.F. Butkevych ◽  
S.V. Dubovskyi ◽  
◽  
...  

Shot analysis of power systems decarbonisation problem to ensure a net-zero greenhouse gas emissions is given. The mathematical model of the power system capacity balancing, generating capacities of which are renewables and nuclear power plants (NPP) is proposed. For capacity balancing storage power plants (SPP) with specified efficiency indicators are used. By using the indicators of the operational conditions of the IPS of Ukraine in 2019 and mathematical modeling for various options of the NPP installed capacity in the decarbonised IPS of Ukraine, the needs in the renewables installed capacity and in the capacity and energy of various types of the SPP were estimated. References 10, figures 4, tables 2.


Author(s):  
Kwabena Addo Pambour ◽  
Burcin Cakir Erdener ◽  
Ricardo Bolado-Lavin ◽  
Gerard P. J. Dijkema

Gas and power networks are tightly coupled and interact with each other due to physically interconnected facilities. In an integrated gas and power network, a contingency observed in one system may cause iterative cascading failures, resulting in network wide disruptions. Therefore, understanding the impacts of the interactions in both systems is crucial for governments, system operators, regulators and operational planners, particularly, to ensure security of supply for the overall energy system. Although simulation has been widely used in the assessment of gas systems as well as power systems, there is a significant gap in simulation models that are able to address the coupling of both systems. In this paper, a simulation framework that models and simulates the gas and power network in an integrated manner is proposed. The framework consist of a transient model for the gas system and a steady state model for the power system based on AC-Optimal Power Flow. The gas and power system model are coupled through an interface which uses the coupling equations to establish the data exchange and coordination between the individual models. The bidirectional interlink between both systems considered in this studies are the fuel gas offtake of gas fired power plants for power generation and the power supply to LNG terminals and electric drivers installed in gas compressor stations and underground gas storage facilities. The simulation framework is implemented into an innovative simulation tool named SAInt (Scenario Analysis Interface for Energy Systems) and the capabilities of the tool are demonstrated by performing a contingency analysis for a real world example. Results indicate how a disruption triggered in one system propagates to the other system and affects the operation of critical facilities. In addition, the studies show the importance of using transient gas models for security of supply studies instead of successions of steady state models, where the time evolution of the line pack is not captured correctly.


2019 ◽  
Vol 114 ◽  
pp. 05007 ◽  
Author(s):  
Felix Byk ◽  
Yana Frolova ◽  
Ludmila Myshkina

The existing centralized power supply system has the alternative due to distributed generation. By certain conditions distributed cogeneration allows to increase the reliability and quality of power supply and to reduce the cost of electricity for consumers. Therefore, a lot of energy-intensive consumers switched to their own power supply systems, as it turned out to be a competitive technical solution. The total gasification of the country’s regions and the presence of domestic manufacturers of gas turbine and gas piston power plants accelerated this process. Nowadays local power systems are emerging with cogeneration plants are the main source of heat and electricity there. The feasibility justification of the kind and type of generation is determined by many factors, including circuit-mode parameters in the local power system and adjacent network. Local power systems based on the principles of self-balance are proposed to name as energy cells. The integration of energy cells with regional power system increases the technical and economic effectiveness of power supply system for consumers. The proposed power systems transition leads to certain systemic effects. Received effects are depending on functions of distributed generation. This paper explores the impact of scheme and mode factor on the technical effects.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 158 ◽  
Author(s):  
Harun Or Rashid Howlader ◽  
Oludamilare Bode Adewuyi ◽  
Ying-Yi Hong ◽  
Paras Mandal ◽  
Ashraf Mohamed Hemeida ◽  
...  

Energy storage systems (ESSs) are essential to ensure continuity of energy supply and maintain the reliability of modern power systems. Intermittency and uncertainty of renewable generations due to fluctuating weather conditions as well as uncertain behavior of load demand make ESSs an integral part of power system flexibility management. Typically, the load demand profile can be categorized into peak and off-peak periods, and adding power from renewable generations makes the load-generation dynamics more complicated. Therefore, the thermal generation (TG) units need to be turned on and off more frequently to meet the system load demand. In view of this, several research efforts have been directed towards analyzing the benefits of ESSs in solving optimal unit commitment (UC) problems, minimizing operating costs, and maximizing profits while ensuring supply reliability. In this paper, some recent research works and relevant UC models incorporating ESSs towards solving the abovementioned power system operational issues are reviewed and summarized to give prospective researchers a clear concept and tip-off on finding efficient solutions for future power system flexibility management. Conclusively, an example problem is simulated for the visualization of the formulation of UC problems with ESSs and solutions.


Sign in / Sign up

Export Citation Format

Share Document