Research of Compensated AC Regulated Power Supply in Electric Power Systems Based on a High-Frequency Isolated Transformer

2013 ◽  
Vol 676 ◽  
pp. 227-230
Author(s):  
Qi Liang Zhang ◽  
Ping Wang ◽  
Liu Yang

In this paper, a new topology of compensated AC regulated power supply (ACRPS) in electric power systems based on a high-frequency isolated transformer (HFIT) is proposed. In order to overcome the slow response and low accuracy of the existing ACRPS, the phase shift regulating control (PSRC) based on instantaneous value of voltage single closed loop is applied as well as the software phase locked loop (SPLL). The proposed ACRPS has been simulated in the case of the voltage fluctuation, harmonics and frequency shift with Matlab. The simulation results show that output voltage precision is controlled within 0.5% and total harmonic distribution (THD) can be limited to less than 1%. In a word, the feasibility of the proposed ACRPS is effectively verified.

2021 ◽  
Author(s):  
Sergey Goremykin

The textbook describes the main issues of the theory of relay protection and automation of electric power systems. The structure and functional purpose of protection devices and automation of power transmission lines of various configurations, synchronous generators, power transformers, electric motors and individual electrical installations are considered. For each of the types of protection of the above objects, the structure, the principle of operation, the order of selection of settings are given, the advantages and disadvantages are evaluated, indicating the scope of application. The manual includes material on complete devices based on semiconductor and microprocessor element bases. The progressive use of such devices (protection of the third and fourth generations) is appropriate and effective due to their significant advantages. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for students in the areas of training 13.03.02 "Electric power and electrical engineering" (profile "Power supply", discipline "Relay protection and automation of electric power systems") and 35.03.06 "Agroengineering" (profile "Power supply and electrical equipment of agricultural enterprises", discipline "Relay protection of electrical equipment of agricultural objects"), as well as for graduate students and specialists engaged in the field of electrification and automation of industrial and agrotechnical objects.


2013 ◽  
Vol 676 ◽  
pp. 218-221
Author(s):  
Xiao Hui Zeng ◽  
Yong Hui Chen ◽  
Gong Quan Tan

A fault phase selection method is proposed based on arc voltage after analysis of inadequate of fault phase selector existed in the paper. A precise fault phase selection can be achieved by using arc voltages in conjunction with phase current differences and sequence components of currents. The method proposed can solve false tripping problems in transmission line protections when single phase to ground faults occur with great reliabilities. Simulation results show that the method can identify faulted phase or phases correctly and effectively.


2013 ◽  
Vol 676 ◽  
pp. 222-226
Author(s):  
Jian Zhou Quan ◽  
Sheng Hua Wu ◽  
Peng Ju Cao ◽  
Jian Shi Xu

To achieve safety commutation of the bidirectional switch in Matrix Sinusoidal waveform converter with high-frequency link, a decoupling time-driven strategy is proposed in this paper. The two gates in each bidirectional switch are driven by different signals, so the voltage surge caused by non-synchronous commutation of two bidirectional switches can be avoided, and both ZVS and ZCS are also achieved. Since the current polarity of load need not to be detected, the circuit is easy in realization. Experiments has been carried out to verify the feasibility of the proposed method.


2005 ◽  
Vol 20 (3) ◽  
pp. 2281-2288 ◽  
Author(s):  
I.-Y. Chung ◽  
S.-W. Park ◽  
H.-J. Kim ◽  
S.-I. Moon ◽  
B.-M. Han ◽  
...  

Author(s):  
И.А. Богданов ◽  
Н.Д. Сенчило

Качественная и надежная работа электрических машин и устройств в электроэнергетических системах судов с электродвижением является одной из наиболее важных приоритетов для сохранности жизни и здоровья экипажа, судового оборудования и выполнения поставленных задач. Одним из основных критериев качества электроэнергии является напряжение. В статье рассмотрены факторы возникновения провалов напряжения в судах с электродвижением и способы поддержания параметров электроэнергии в рамках ГОСТ 32144-2013. В статье представлены результаты исследований порогов чувствительности по напряжению различных систем и устройств электроснабжения. Описаны основные методы обеспечения оптимального уровня напряжения. На основе описанных методов разработан алгоритм компенсации провалов напряжения система, позволяющий решить все поставленные задачи по обеспечению нормативных параметров качества электроснабжения судна с электрическим приводом. Описанный алгоритм автоматического регулирования реализуется на основе fuzzy-логики с возможностью совмещения методов реактивной компенсации, синфазной компенсации и полной компенсации. Одним из результатов работы является модель сети электроснабжения с динамическим компенсатором последовательного типа, совмещающая векторные настройки, фильтр-компенсирующие устройства и нечеткую логику в среде MatLab Simulink. В статье подробно описан функционал представленной модели. Представлены графические и качественные показатели работы разработанной модели. В результате научного исследования выявлена эффективность применения предложенного устройства динамической компенсации в задачах устранения провалов напряжения при его последовательном включении. High-quality and reliable operation of electric machines and devices in the electric power systems of electric propulsion watercrafts is one of the most important priorities. This article reflects the reasons of voltage dips and their impact of watercrafts equipped with electric motor, as well as describes the importance of maintaining the quality of ship power supply. Presented research describes a determined voltage sensitivity threshold for various power supply systems and devices. The result of research is optimal method for compensating voltage dips and developed operational algorithm of the compensator. The described automatic control algorithm is implemented on the basis of fuzzy-logic with the possibility of combining the methods of reactive compensation, common-mode compensation and full compensation. As a result of the work, a power supply network model with a sequential-type dynamic compensator was designed, combining vector settings, filter-compensating devices and fuzzy logic in the MatLab Simulink environment, and the functional part of the model is described in detail. The article contains functional diagrams of described model, as well as graphic and quality indicators of the developed model. In a conclusion, the scientific research reveals the effectiveness of the proposed device of dynamic compensation with sequential inclusion in the tasks of eliminating voltage dips.


2019 ◽  
Vol 139 ◽  
pp. 01012
Author(s):  
T.N. Nasirov ◽  
V.A. Nepomnyashchiy ◽  
O.V. Radionova

Reviewed and analyzed issues related to the reliability of electricity supply in non-full-phase modes of electrical networks, to calculate which use adaptive methods, is built on one Central principle of modeling the modes of electric power systems (EPS). Special attention is paid to the calculation of damages from no full provided of electricity in non-full-phase modes.


Dependability ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 47-52
Author(s):  
A. M. Koniukhov ◽  
A. V. Khlebnov ◽  
V. A. Timanov

The Aim of the paper is to show that improved power supply reliability and electric power system stability are achieved by applying new methods of testing relay protection and automation (RPaA). Major cascading failures in electric power systems are caused by cascading effects, i.e., effects involving several successive effects of various nature. Cascading effects allow extending the functionality while testing RP&A and taking into account the time factor in the context of effects of various nature. Method. A method is proposed for testing relay protection and automation taking into account the cascading effect that is used in the process of development, calibration and installation of protection devices for operation in predefined modes for the purpose of improved power supply reliability and unfailing stability of electric power systems. Result. Intermittent cascading effects do not allow the relay protection and automation recover the electric power system from the post-emergency mode, thus reducing the dynamic stability to the critical level. The diagram of relay protection and automation exposure allows taking into consideration the environmental effects in the process of testing the relay protection and automation. Conclusion. The proposed method of cascading exposure as part of testing relay protection and automation can be used in the process of development, calibration and installation of electric power systems protection and will enable improved stability of electric power systems and reliability of power supply.


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