scholarly journals A review of the protection for the multi-terminal VSC-HVDC grid

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Bin Li ◽  
Jiawei He ◽  
Ye Li ◽  
Botong Li
Keyword(s):  
Power System ◽  
Power Supply ◽  
Traveling Wave ◽  
Differential Protection ◽  
Protection Strategy ◽  
Current Differential Protection ◽  
The Future ◽  
Dc Line ◽  
Supply Reliability ◽  
Pilot Protection

AbstractThe multi-terminal VSC-HVDC grid is believed to be widely applied in the future power system. The dc line protection is the key technique for operation security and power supply reliability of the dc grid. In this paper, the single-ended protections, namely, the traveling-wave based protection and transient-variable based protection, as well as the pilot protections, mainly including the directional pilot protection and current differential protection, are discussed in detail. With the analyzed protections, the effective main and back-up protection strategy can be configured for the dc line in multi-terminal VSC-HVDC grid.

scholarly journals An Adaptive Differential Protection and Fast Auto-Closing System for 10 kV Distribution Networks Based on 4G LTE Wireless Communication

2019 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Wen An ◽  
Jun Jie Ma ◽  
Hong Yang Zhou ◽  
Hong Shan Chen ◽  
Xu Jun ◽  
...  
Keyword(s):  
Control System ◽  
Wireless Communication ◽  
Power System ◽  
Power Supply ◽  
Distribution Networks ◽  
Fault Isolation ◽  
Differential Protection ◽  
Current Differential Protection ◽  
Protection And Control ◽  
And Control

With the development of wireless communication technology and computer technology, more and more smart technologies have been applied in electricity distribution networks. This paper presents an adaptive current differential protection and fast auto-closing system for application in 10 kV distribution networks in China Southern Power Grid. The current differential protection can adaptively change its settings according to the topology change of the primary distribution networks, thus the system effectively reduces the operation and maintenance cost of the power distribution network. In order to restore the power supply for the healthy part of the 10 kV networks quickly after a power system fault is cleared, the protection and control system provides wide area control function for automatic fault isolation and automatic switching. The traditional overcurrent protection and control system have no fault location function, it may take several minutes or even hours to manually locate a fault and then restore the power supply. Compared with the protection and control system of the traditional 10 kV distribution networks, the system developed can locate and isolate faults within 900 ms (assuming that the operating time of the load switch is 700 ms), and can quickly restore power supply in less than one second after a power system fault is cleared.

scholarly journals Determination of reliability of power supply of ship's responsible power receivers

2020 ◽  
pp. 22-26
Author(s):  
С.Е. Кузнецов ◽  
Н.А. Алексеев ◽  
А.А. Виноградов
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Supply ◽  
Electric Power System ◽  
Time To Failure ◽  
Parallel Operation ◽  
Diesel Generator ◽  
Operating Modes ◽  
Reliability Indicators ◽  
Supply Reliability

Изложена методика расчета показателей безотказности электроснабжения (вероятности безотказного электроснабжения и средней наработки до отказа) ответственных приемников морского судна, подключаемых к аварийному электрораспределительному щиту. Методика реализована применительно к судовой электроэнергетической системе с тремя источниками электроэнергии – двумя основными дизель-генераторными агрегатами, подключенными к главному электрораспределительному щиту, и одним аварийным дизель-генераторным агрегатом, подключенным к аварийному электрораспределительному щиту. Рассмотрены различные режимы работы судовой электроэнергетической системы: при работе до первого отказа одного основного дизель-генератора, при параллельной работе двух основных дизель-генераторов, при работе одного аварийного дизель-генератора; а также после обесточивания с учетом возможности последующего включения резервного или (и) аварийного дизель генератора. Методика, с соответствующими корректировками, может быть использована для расчета показателей безотказного электроснабжения в судовых электроэнергетических системах другой комплектации. Расчет показателей безотказности электроснабжения необходим при проектировании для обеспечения требуемого уровня надежности электроснабжения судовых приемников электроэнергии, а при эксплуатации – для предупреждения отказов и планирования технического обслуживания и ремонта элементов судовых электроэнергетических систем. The methodology for calculating the indicators of the reliability of power supply (the probability of failure-free power supply and the mean time to failure) of critical receivers of a sea vessel connected to the emergency electrical switchboard is presented. The technique is implemented in relation to a ship power system with three sources of electricity - two main diesel generator sets connected to the main electrical switchboard, and one emergency diesel generator set connected to an emergency electrical switchboard. Various operating modes of the ship's electric power system are considered: during operation until the first failure of one main diesel generator, during parallel operation of two main diesel generators, during operation of one emergency diesel generator; as well as after de-energizing, taking into account the possibility of subsequent switching on of the backup and / or emergency diesel generator. The technique, with appropriate adjustments, can be used to calculate indicators of reliable power supply in ship power systems of a different configuration. Calculation of power supply reliability indicators is necessary during design to ensure the required level of power supply reliability for ship power receivers, and during operation - to prevent failures and plan maintenance and repair of elements of ship power systems.

Modeling and Practice of Wind/PV/Pumped-Storage Hybrid System

2014 ◽  
Vol 541-542 ◽  
pp. 892-897 ◽  
Author(s):  
Peng Fei Yi ◽  
Jian Zhang ◽  
Zhao Yuan Zhang
Keyword(s):  
Power System ◽  
Power Supply ◽  
Hydro Power ◽  
Hybrid Power System ◽  
Hybrid Power ◽  
Investment Cost ◽  
Important Sense ◽  
Pumped Storage ◽  
Installed Capacity ◽  
Supply Reliability

This paper built a hybrid power system, including wind power, PV power and hydro power generation. It is presented mathematical model for the optional design of hybrid power system. The object of the model are to minimize the initial investment cost, power supply reliability and power complementation. The constraint condition are included system working, installed capacity and load balance, So the capacity matching model is established. A stand-alone photovoltaic of pasturing area is calculated by using the model. The result shows that the optional design model have an important sense, which improved power supply reliability, complementary characteristics of hybrid power and reduce the total cost of the system.

scholarly journals A Novel Pilot Protection Principle Based on Modulus Traveling-Wave Currents for Voltage-Sourced Converter Based High Voltage Direct Current (VSC-HVDC) Transmission Lines

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2395 ◽  
Author(s):  
Xiangyu Pei ◽  
Guangfu Tang ◽  
Shengmei Zhang
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Traveling Wave ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Hvdc Transmission Lines ◽  
Dc Line ◽  
Voltage Sourced Converter ◽  
Pilot Protection

Protection for transmission lines is one of crucial problems that urgently to be solved in constructing the future high-voltage and large-capacity voltage-sourced converter based high voltage direct current (VSC-HVDC) systems. In order to prevent the DC line fault from deteriorating further due to the failure of main protection, a novel pilot protection principle for VSC-HVDC transmission lines is proposed in this paper. The proposed protection principle is based on characteristics of modulus traveling-wave (TW) currents. Firstly, the protection starting-up criterion is constructed by using the absolute value of the 1-mode TW current gradient. Secondly, the fault section identification is realized by comparing the polarities of wavelet transform modulus maxima (WTMM) of 1-mode initial TW currents acquired from both terminals of the DC line. Then, the selection of fault line is actualized according to the polarity of WTMM of local 0-mode initial reverse TW current. A four-terminal VSC-based DC grid electromagnetic transient model based on the actual engineering parameters is built to assess the performance of the proposed pilot protection principle. Simulation results for different cases prove that the proposed pilot protection principle is excellent in reliability, selectivity, and robustness. Moreover, the data synchronization is not required seriously. Therefore, the proposed novel pilot protection principle can be used as a relatively perfect backup protection for VSC-HVDC transmission lines.

Factors Affecting the Future of Power Supply Industry

2012 ◽  
pp. 13-26
Keyword(s):  
Power System ◽  
Power Supply ◽  
Planning Process ◽  
Power System Planning ◽  
System Planning ◽  
Factors Affecting ◽  
The Future ◽  
Supply Industry ◽  
Thinking Process ◽  
Guiding Principles

The understanding of all factors that might influence the planning process directly and indirectly is a prerequisite to guaranteeing a realistic outcome. This understanding provides the guiding principles and outer boundaries of the concepts and thinking process involved in power system planning.

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