Research on Reliability of Relaying Protection in Smart Substation

Research on reliability of relaying protection in smart substation not only has a positive effect on the rational configuration scheme of relaying protection in smart substation, but also can promote the stability and safety of the overall operation of power system. There are many reliability strategies for relaying protection in smart substation. In practice, the key points of relaying protection should be clarified. Based on the reality, the protection configuration should be strengthened;the voltage limited delay should be used for protection, and the protection configuration scheme of actual lines should be paid attention to, so as to improve the reliability of relaying protection in smart substation and promote the realization of stable and sustainable development of power system and smart substation.

Research on the Process Layer and Substation Layer Relay Protection in Smart Substation Relay Protection

The intelligent substation relay protection facility is a fundamental element in construction of modern power system,based on the principles of flexibility,security and accuracy,and it can be divided into process layer and substation layer according to specific equipment.The former is suitable for individual sampling of disposable equipment,can be separated from the base station synchronization sampling,with the help of synchronous digital system and ping-pong algorithm to achieve synchronization of the overall sampling,that is to take the distribution protection components,through the separate transmission medium to realize the information transmission;the latter is for variable power plant components centralized backup protection,taking online real-time tuning technique.

The Research of Intelligent Substation Time Synchronization System and the Influence of Its Fault to Relay Protection

The intelligent substation realizes the digitization of information in the whole substation and thus time synchronization system becomes more and more important. This paper introduces time synchronization technology of intelligent substation and puts forward the principles for designing intelligent substation time synchronization system. According to some relay protection malfunction examples caused by time synchronization system fault, analyze the influence of time synchronization system fault to relay protection and correspondingly put forward some improving measures.

Advanced Communication System in Substation for Integrated Protection

This paper proposes an advanced substation integrated protection communication system based on the latest development in power system.The integrated protection communication system within a substation comprises a number of major components such as the merging unit, communication network and integrated protection unit.The design and capability evaluation of the communication network based on IEC61850 are focused on.Results show that huge information from 4 merging units can be transmitted real-time via adopting 100 Mbit/s optical fiber in a substation,and the proposed communication network is able to achieve required performance.

Fault Detection and Protection System of Electric Railway Substation

The industrial power systems are moving to digital networks,and unmanned systems are increasing recently with the technological development of information and communication technology.In particular,reliability of system operation is very important for stable power supply.Most industrial power distribution facilities use a 154 kV or 22.9 kV extra HV(high voltage)power system,and a special monitoring system is required because a large loss occurs when an error occurs in the power facility in the field.Although digital protection relay(IED;intelligent electronic device)and FR(fault recorder)are applied to the field to protect the power system,various improvement activities are still ongoing.In this paper,a 22.9 kV high-voltage panel and its test bed,which are widely used in railway stations,tunnels,substations and large plants,were tested as test subjects.The developed fault detection system automatically starts the AL(auto-lock)circuit or outputs an alarm signal to user by monitoring in real time problems such as CT(current transformer)-open and poor-contact that the existing digital protection relay cannot cover.In addition,it is intended to increase the safety and reliability of the power system by blocking various accidents in the system in advance and accurately analyzing the causes of faults with the developed fault detection system.

Comparative Study on Substation Shielding Due to Direct Lightning Strokes

Malaysia is one of the many countries that experience high lightning related activities. In fact, according to Malaysian Meteorological Department the Ground Flash Density (GFD) in Malaysia, it is rated at the fifth place in the ten most lightning cities of the world, with a high keraunic level, which is 240 thunderstorm days per year, and in other words, a Ground Flash Density (GFD) of 48.3 flashes per square kilometer per year. In the power systems, high keraunic level would contribute to high possibility of power interruptions such as disruption, degradation, damage and downtime. These outages would ultimately lead to revenue losses and reduction of network reliability. These lightning related interruptions may be in terms of direct lightning strikes to the lines or to the equipments in the substation. By the use of Mat Lab GUI (Graphic Users Interface), this study presents a simple computer program which uses the electro-geometric model (EGM) for the designing of substation shielding systems. The EGM uses the concept where the protection zone of a lightning system lies within the radius where the upward channel initiates and propagates through the air terminal to meet the downward leader. This interception point is called “the point of discrimination” and is where the downward leader decides its final jump. The distance at which the last jump occurs is known as the striking distance. With the use of the striking distance and the mathematical equations developed by Young, Brown-Whitehead, IEEE-1992 (IEEE T&D Committee Equations) and IEEE-1995 (IEEE Substations Committee Equations). This project aimed to investigate, understand and analyse the substation protection by means of masts and shield wires. The analysis is extended to account for lightning protection provided by single mast to two masts as well as from single shield wire to double shielding wires. The outcomes of these four equations will be compared.

Reliability analysis for vertical integration of protection,measurement,merge unit,and intelligent terminal device

The reliability analysis of vertically integrated protection devices is crucial for designing International Electrotechnical Commission(IEC)61850-based substations.This paper presents the hardware architecture of a four-inone vertically integrated device and the information transmission path of each function based on the functional information transmission chain of protection devices,measurement and control devices,merging units,and intelligent terminals.Additionally,a reliability analysis model of the protection device and its protection system is constructed using the fault tree analysis method while considering the characteristics of each module of the vertically integrated device.The stability probability of the protection system in each state is analyzed by combining the state-transfer equations of line and busbar protection with a Markov chain.Finally,the failure rate and availability of the protection device and its protection system are calculated under different ambient temperatures using a 110 kV intelligent substation as an example.The sensitivity of each device module is analyzed.

The Automated System of Unified Templates as an Element of Trainability of Microprocessor Relay Protection Devices

The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.

Simulation Studies of an Integrated Overcurrent Relay Protection Scheme for Distribution Systems

This paper presents an integrated protection technique for power distribution systems. A novel integrated protection scheme based on overcurrent protection technique for distribution system is described, in which a specially designed protection relay is installed at each substation of a network and responsible for the protection of every line sections connected to the substation busbar The conventional directional overcurrent and the new adaptive accelerated protection algorithms with multiple settings are implemented into the relay to cover all the protected line sections. The paper includes studies of a typical multi section distribution network to demonstrate the principle of the scheme. Studies show that the new scheme not only offer the new protection features for individual power line section, but also provide the characteristics of integrated protection.

A Compound Relay Protection Operation Criterion Based on Kirchhoff’s Current Law and Abnormal Data Detecting Algorithm

A compound relay protection operation criterion is proposed based on Kirchhoff’s Current Law and abnormal data detecting algorithm. The abnormal data detecting algorithm are proposed after deep research on the abnormal data properties. The current transformer status monitoring system and current phase angle detecting system is introduced. A simulation model containing different power sources and loads is established in Matlab. The simulation results show that this compound criterion can work quickly and reliably in all conditions.

A Design of 220 kV Line Protection Action Deduction System Based on Numerical Simulation

Accurate conditions monitoring and early wrong action warnings of relay protection in the Smart Substation is the basic guarantee to realize the normal operation of primary and secondary system of the power grid.At present,the traditional operation and maintenance monitoring methods of relay protections have poor timeliness,while some automatic monitoring methods have insufficient early warning performance,and lack the online action deduction function independent of the actual device.In this paper,a design method of integrated action deduction system including protection logic reasoning and software and hardware operation condition is proposed.The system can receive real-time operation information of protection online,simulate different types of faults,and output the recording information of sub modules belongs to the action deduction system.It can realize the online monitoring of device faults such as deducing the correctness of setting values at a certain time in the future,giving the wrong action warnings and predicting the probability of them as well,which effectively improves the operation and maintenance efficiency of the secondary system in the intelligent substation.

Comprehensive Automation of Microprocessor Protection Relay Terminals Operated on AC Railways

The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.

Impact of Sensor Technology for Line Protection Performance

The paper has presented the impact on the line protection performance with the introduction of MUs （merging units） in the process bus level. The paper begins with the introduction on modem digital substation structure and process bus. Then, the paper describes the performances of different sensors such as CTs （current transformers）, CVTs （capacitive voltage transformers）, FOCS （fiber optical current transducers） and FOVS （fiber optical voltage transducers）. With the use of above transducers together with MUs, the performance of distance protection function and line differential protection function have been investigated and presented. Finally, conclusions based on the study are presented in the paper.

Natural Ionizing System of Electrical Protection and Energies against Atmospheric Discharges （Lightning）

This is the new highest technology, 100% Venezuelan and unique in the world, technological innovation, world patent for maximum protection, security and zero risk （0） to all electrical and power generation systems： hydroelectric and thermoelectric power plants, wind, nuclear and solar power plants, etc.; it is the only technology around the world that has the potential to disperse and propagate to land mass the enormous energies associated to the atmospheric discharges （lightning）, which are in the order： 200,000 to 500,000 Amperes; 1,000 million kilowatts and high-level transient voltage of 100 million volts. This new high technology is the solution to the paradigm of Benjamin Franklin and it is the mechanism to end ＂blackouts＂ that produces so many damages and losses of billions of dollars to both generators and users of electrical service, throughout the world.

Hierarchical protection control system of smart substations

This paper analyzes the problems of the relay protections and secondary circuits of traditional substations,and introduces the hierarchical protection and control system of smart substations based on the technologies like IEC 61850 Standard,electronic instrument transformer,process level network,and wide area optical fiber communication network,etc.The hierarchical protection and control system includes three levels:local area protection,substation area protection and control,and wide area protection and control.These three levels are combined to solve the problems of the relay protections in traditional substations,thus improving protection performance and control capability of the system.

Substation area joint defensive protection strategy based on distributed cooperative all-in-one device

Integration of primary and secondary devices are impelled by the development of smart grid. Based on the ideology of primary and secondary device integration, an all-in-one device and its concept, configuration and function are proposed. Then, an all-in-one device framework of distributed substation area protection is proposed. Point-topoint model and virtual local area network(VLAN) based network-to-network model are adopted in this framework.The dual redundancy on hardware and software level is realized by modularization and protection information mirroring storage/overwriting. Considering the fact that the sampling, logic judgment and information sharing processes of protection may fail in atrocious conditions, a distributed cooperative all-in-one device cluster based substation area joint defensive protection strategy is proposed. The adaptability of sectional component failure in secondary system is strengthened by reusing module function, setting value mirroring storage and dynamic load balancing computing ability to constitute strong intelligent outdoor secondary device integrated network. Finally, the simulation examples based on EPOCHS which consider various system failure conditions are presented to verify the validity and rationality of the proposed architecture and strategy.

Research on Testing Technology of Relay Protection for Intelligent Substations

Intelligent substations adopt various kinds of new technologies, including information sharing technology based on IEC61850, digital sampling technology, synchronization technology, and network transmission technology. Relay protection equipment faces all the challenges brought by the application of these new technologies. After analyzing the demand for test, the authors propose testing methods and technical requirements targeting the test items in great need, including ICD model file test, digital interface performance test, coordination performance test with merging unit and smart terminal, network pressure test. And the problems occurring during the tests are summarized.

Distributed Protection for Smart Substations Based on Multiple Overlapping Units

Taking advantage of the information sharing mechanism in smart substations,a distributed protection based on multiple overlapping units is introduced in this paper.The area division and the construction of protection units are studied based on the principle of differential protection.Mutual perception and information interaction among units,calculation with multisource information and coordinated protection schemes are proposed to improve the reliability and adaptability of the substation protection system.A multi agent system(MAS)approach is used to model the units’working process in various situations,such as communication failure and sampled data failure.Test results demonstrate that the method can accelerate the backup protection as well as reduce the power-off range.

Teaching Protective Relaying Design and Application Using New Modeling and Simulation Tools

As the smart grid concepts are emphasized lately, the need to modernize the power engineering education is also well recognized. This paper presents a set of newly developed modeling, simulation and testing tools aimed at better understanding of the design concept and related applications for protective relaying and substation automation solutions for the smart grid. Since the smart grid applications require integration of data from multiple IEDs （intelligent electronic devices）, understanding properties of each IED type in detail, as well as their responses to the power system events is needed. In addition, understanding the communication requirements to perform data integration is also important. To illustrate how the mentioned smart grid issues may be taught, the following advanced teaching approaches are presented： （1） Use of modeling and simulation means to better understand interaction between the relays and power system; （2） Use of IED test facilities to better understand performance of physical devices used for protection, monitoring and control; （3） Utilization of communication network modeling tools to simulate the communication network within SAS （substation automation system）. Examples showing the use of proposed techniques for teaching the fundamentals and applications are presented. The examples demonstrate the adequacy and efficiency of the proposed techniques.

电力信息物理系统中信息系统物理化的建模及分析方法

该文基于信息系统物理化的设想提出电力信息物理系统(cyber-physical power system,CPPS)中的信息流建模和计算分析方法。采用连续时间函数来刻画信息流的特征,并定义信息网络运行参数为流量累积函数、信息流速和时延。首先,基于遍历法搜索出信息流路径,建立信息流速矩阵的范式;然后利用改进的网络演算(network calculus,NC)特性赋值流速矩阵的元素;进一步采用流量累积函数表征信源数据发送规律,从而显式求解时延上界。最后将提出的信息流建模方法应用于智能变电站自动化系统的时延计算,通过与OPNET的仿真结果相比较,验证所提出模型的有效性,而且该方法可以提供定量分析指标以优化变电站组网方案设计中的信息流分布。