scholarly journals Fast frequency oscillations detection in low inertia power systems with excessive demand-side response for frequency regulation

2021 ◽  
Vol 19 ◽  
pp. 557-560
Author(s):  
Leo Casasola-Aignesberger ◽  
◽  
Sergio Martinez

The reduction in inertia present in electric power systems due to the increase in renewable generation interfaced with power converters presents various challenges in power system operation. One of these challenges is keeping the frequency of the system within acceptable bounds, as the reduced inertia allows faster changes in frequency. A possible way to mitigate this effect is to introduce a certain degree of frequency response in the demand side, in such a way that a loss in generation leads to a decrease in the demanded power, levelling the generation-demand balance. In this paper, one limitation of this approach is analysed, specifically the case where the demand response is excessive to the system inertia and demand, producing fast frequency oscillations. A scenario where this happens, on a simulated islanded system based on the electric power system of the island of San Cristóbal, in Galápagos (Ecuador), is studied, and a method of detecting these oscillations is proposed, as a first step to develop an appropriate response to them.

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.


Vestnik MEI ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 11-18
Author(s):  
Nailia Sh. Chemborisova ◽  
◽  
Ivan D. Chernenkov ◽  

The problem of selecting the electric power system control nodes is studied. By performing control of these modes, matters concerned with providing reliable power supply of the required quality to consumers can be settled in the most efficient manner. As an example, a fragment of the electric power system mathematical model used in the Finist mode-setting simulator for a power system dispatch control center operator is considered, which represents a highly branched electrical network consisting of eleven 110 kV nodes, three 220 kV nodes connected with the system, and two generator nodes. A new procedure for selecting the control nodes is proposed, which takes into account a combination of different indicators having different measurement units, dimensions and scales is proposed. These indicators characterize the following properties of power system nodes: the reactive power fraction absorbed at a node, the sensitivity of voltage to reactive load variations, the number of connected power lines, and statistical indicators characterizing the change of voltage at the nodes and reactive power flows for different options of installing the reactive power compensation devices. For combined use of these indicators, they were ranked according to the efficiency of installing reactive power compensation devices in the system. For each indicator, a scale of five ranks (intervals) is set, which determine the preferences (qualitative judgments) of the researcher in evaluating the reactive power compensation devices installation efficiency at the system nodes. The highest rank (5) corresponds to the maximum efficiency, and the lowest rank (1) corresponds to the minimum efficiency. To calculate the individual (integral) priority indicator of installing reactive power compensation devices, the ranks of indicators are added together, and their sum is divided by the product of the number of ranks by the number of the used indicators (features). Based on the calculation results, the rating (location) of each node is determined, and the nodes for installing the reactive power compensation devices are selected according to their effect on ensuring the electric power system operation reliability, active power losses in the network, and voltage regulation. Thus, a new procedure is presented for determining the integral indicators for comprehensively estimating the properties of complex electric power system nodes and selecting the controlled nodes using a system of various indicators. These indicators characterize the studied nodes in terms of the efficiency of installing reactive power compensation devices to reduce active power losses in the network, voltage regulation, and ensuring the electric power system operational reliability. The validity of the results obtained in the study is confirmed by their comparison with the indicators of the balance-conductivity method, which has proven itself in solving problems connected with determining the nodes for controlling electric power system operation modes.


2013 ◽  
Vol 2 (4) ◽  
pp. 44-58 ◽  
Author(s):  
E. V. Markova ◽  
I. V. Sidler ◽  
V. V. Trufanov

The first part of the paper is devoted to the problem of optimal control in the area of electric power industry which is described on the basis of a one-sector variant of Glushkov integral model of developing systems. The authors consider the ways uncertain conditions of future electric power system development influence the optimal service life. The results of calculations for the Unified Electric Power System of Russia are presented and analyzed. The second part of the paper deals with the application of Prony method to identification of the Volterra equations in the two-sector models of developing systems. The authors suggest a numerical method for identifying the efficiency function parameters. An illustrative example is given.


2019 ◽  
Vol 24 ◽  
pp. 02012
Author(s):  
Yury Shornikov ◽  
Evgeny Popov

Transients in electric power systems are of great interest to power engineers when designing a new or maintaining an existing system. The paper deals with using hybrid system theory for modeling and simulation of an electric power system with controllers. The presented technique is rather convenient and recommended as mathematical models of transients in electric power systems with controllers in general contain both continuous and discrete components. The modeling and simulation were carried out in the modeling and simulation environment ISMA, which is briefly presented in the paper.


2018 ◽  
Vol 100 (4) ◽  
pp. 2677-2693 ◽  
Author(s):  
Michel Rezkalla ◽  
Michael Pertl ◽  
Mattia Marinelli

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Agustín Flores ◽  
Eduardo Quiles ◽  
Emilio García ◽  
Francisco Morant ◽  
Antonio Correcher

This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system.


2018 ◽  
Vol 55 (2) ◽  
pp. 3-10
Author(s):  
A. Obushevs ◽  
A. Mutule

Abstract The paper focuses on the application of synchrophasor measurements that present unprecedented benefits compared to SCADA systems in order to facilitate the successful transformation of the Nordic-Baltic-and-European electric power system to operate with large amounts of renewable energy sources and improve situational awareness of the power system. The article describes new functionalities of visualisation tools to estimate a grid inertia level in real time with monitoring results between Nordic and Baltic power systems.


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