Wide Area Protection System Research Articles

Analyses and Discussions of the Blackout in Indian Power Grid

Widespread blackouts of “7.30” and “7.31” occurred in India in 2012. Severe problems in the infrastructure, operation and management in India power grid have come to light after the successive blackouts. The fundamental reason and trigger factors are analyzed in this paper first. Based on the similar characteristics between China power grid and India power grid, in the case of Chinese grid, lessons of preventing blackout of large power grid were discussed by analysis and comparison, mainly on harmonious development and interactive operation of source-grid-load, and construction of wide-area protection system. Suggestions are proposed to improve the security and stability of large power grid with coordinated control system.

Wide-Area Protection Fault Identification Algorithm Based on Multi-Information Fusion

Wide-area protection systems can be used to avoid complicated setting coordination of traditional backup relays and effectively prevent cascading trip events. Since they depend on a multisource data of transmission network to identify a faulted element, fault-tolerance capacity of the system is required. This paper proposes a faulted element identification algorithm based on multisource information fusion for wide-area protection. A fault identification encoding method based upon grid topology is presented. Meanwhile, the operation information of traditional primary/backup relays and the status of breakers are utilized to establish fitness function and state expectation function. The fitness of protected elements is used to determine their fault probability; and faulted elements are identified with high fault tolerance. The property of the presented algorithm is validated by simulation tests based on an IEEE 10-generator 39-bus system.

Research and Engineering Practice of Wide area Protection and Control Systems

Wide area protection (WAP) system is a control and protection system based on power grid information through network communication. WAP can determine fault location and clear fault selectively and quickly, then analysis the effect of power system stability after fault components disconnection and take appropriate control measures. WAP consists of master and slave station. With wide area information, WAP can solve the setting and matching difficulty of protective relaying, and can shorter the delay time of back-up protection. WAP also can improve the level of power system security and stability operation, and coordinate protective relaying and stability control. Obtain real-time wide area information reliably and accurately is the key point to build WAP. The reliability of network, synchronization accuracy, and the efficiency of communication protocols are key technologies of WAP. Full use of wide area information to get smarter, more reliable and more adaptable control strategy that coordinated protective relaying and stability control is the core contents of WAP. This paper summarizes the theory and engineering problems countered in the process of WAP research and application, and introduces the solutions or ideas. This paper brings out several urgent problems to be solved in order to promote WAP technology, and gives outlook of key issues in the implementation WAP at smart substation.

Cooperation Mechanism of Wide-area Protection System Based on Multi-Agents

With the rapid growth of power system, it is becoming increasingly difficult to realize reach and time coordination for conventional backup protection. To cope with those problems, wide-area protection is widely researched. In this paper, a novel dynamic cooperation mechanism of wide-area protection is proposed, which can operate better than distributed and centralized systems with respect to reliability, section selectivity, and so on. The multi-agents technology is used to enhance adaptability and decrease communication traffic of wide-area protection system. The improvement of backup protection performance to overcome some specific conditions, such as communication bit error, protection failure, and breaker failure, is also illustrated by utilizing communication networks and distributed protection agents which enables an easy and flexible construction and operation of the proposed wide-area protection system. The example analysis on IEEE 5 nodes system shows the concrete cooperation processing among agents in the cases of typical faults. DOI: http://dx.doi.org/10.11591/telkomnika.v11i1.1888

Architecture and Fault Identification of Wide-area Protection System

W ide-area protection system (WAPS) is widely studied for the purpose of improvi ng the performance of conventional backup protectio n . In this paper, the system architecture of WAPS is proposed and its key technologies are discussed in view of engineering projects . So a mixed structure-centralized-distributed structure which is more suitable for WAPS in limited power grid region, is obtained based on the advantages of the centralized structure and distributed structure. Furthermore, regional distance protection algorithm was taken as an example to illustrate the functions of the constituent units . F aulted components can be detect ed based on multi-source imformation fuse in the algorithm. A nd the algorithm can not only improved the selectivity, the rapidity, and the reliability of relaying protection but also has high fault tolerant capability . A simulation of 220 kV grid systems in Easter Hubei province showed the effectiveness of the wide-area protection system presented by this paper.

Architecture and Fault Identification of Wide-area Protection System

Architecture and Fault Identification of Wide-area Protection System

Architecture and Fault Identification of Wide-area Protection System

Wide-area protection system (WAPS) is widely studied for the purpose of improvng the performance of conventional backup protection. In this paper, the system architecture of WAPS is proposed and its key technologies are discussed in view of engineering projects. So a mixed structure—centralized-distributed structure which is more suitable for WAPS in limited power grid region, is obtained based on the advantages of the centralized structure and distributed structure. Furthermore, regional distance protection algorithm was taken as an example to illustrate the functions of the constituent units. Faulted components can be detected based on multi-source imformation fuse in the algorithm. And the algorithm cannot only improve the selectivity, the rapidity, and the reliability of relaying protection but also has high fault tolerant capability. A simulation of 220 kV grid systems in Easter Hubei province shows the effectiveness of the wide-area protection system presented by this paper. DOI: http://dx.doi.org/10.11591/telkomnika.v10i3.604

Study on the Technology of MPLS in Wide Area Protection System

Subject to protection of power system, the article analyzes the communication technologies suitable for the current WAPS like IP exchange technology and MPLS etc. and analyzes the feasibility of these technologies in the field of power system WAPS. After comparative analysis of the current communication means, i.e. physical media and communication model etc., the article proposes a WAPS communication network scheme based on MPLS technology. Finally, the article uses network emulation software OPNET to simulate the communication performance of this communication scheme, compares it with current WAPS communication networks and gets the conclusion that the proposed wide area communication network scheme meets WAPS communication requirements

Smart Grid applications for improved Power System Control

The paper is aiming at implementation of new methods and technologies called Smart Grids in Power Systems Control. Among such new methods and technologies, let us mention e.g., synchronous Phasor Measurements Units (PMU) and their local and/or global applications. PMU are basic units of Wide Area Monitoring System (WAMS), and Wide Area Protection and Control System (WAMPaC). The effective way of validation and verification of Smart Grids functionalities is to use Modelling and Simulation of Power Systems that can be divided into two categories: Engineering Simulators (ES) and Dispatch Training Simulators (DTS). The testing of Electronic devices, Control systems, Protections, PMU and local automata can be realized in “HW–in–the–Loop” methods with help of Real Time Digital Simulator (RTDS). One of possible applications – Sequence Impedance Calculations for Lines – is described in this paper.

Reliability Evaluation of the Communication Network in Wide-Area Protection

Various principles and algorithms of the wide-area protection system (WAPS) have been developed so far. However, there are few discussions about the foundation in implementation of the WAPS (i.e., the corresponding communication system and its reliability). This paper presents a reliability evaluation method for the communication systems in wide-area protection (CSWAP). First, system structure and characteristics of the CSWAP are hierarchically analyzed from layers of substation communication, regional communication, and wide-area communication. The reliability model based on fault-tree analysis for each layer is then established. Second, three reliability indices are introduced. Third, an index calculation method based on sequential Monte Carlo simulation is proposed, which adopts the idea of static handling, takes into account faults and repairs of components, and overcomes several disadvantages of analytical methods, such as complicated calculation and weak adaptability. Finally, a case of the CSWAP in the IEEE 11-bus system is analyzed to summarize the effect factors of its reliability and demonstrate the validity of the proposed method. The results show that the models have definite physical significance, and the proposed method is helpful for quantitative reliability assessment, influencing factor analysis, and weakness identification.

에이전트 기반 컬러 페트리 넷을 이용한 전력 계통의 정보 흐름 모델링: 광역 보호 시스템에의 적용

While most of the existing protection schemes have been designed with local information around individual components, these local schemes are not considered capable of protecting the modern electric power gird with growing complexity. Recent blackouts in North America and Europe have renewed the emphasis on coordinated protection and control actions to avoid systemwide blackouts, utilizing all of the available grid information. Thus, this paper proposes a new methodology, Agent-based Colored Petri Net (ACPN) modeling for systematically representing, modeling and analyzing information flows and interactions among the entities of the electric power grid. The paper demonstrates its efficacy and accuracy by investigating an ACPN model of a wide area protection system for a typical power grid. The proposed modeling and analysis schemes may further provide a framework to help assure reliability and interoperability of diverse smart grid components.

스마트그리드를 위한 자율형 상태관측기 연구

In this study, authors have proposed the autonomous state estimation which has been composed with IEC61850, GPS time synchronization and objective model design concept. The proposed method is able to supervise/correct measurement and communication error from SCADA. The major advantages of the proposed autonomous state estimation are that it is possible to evaluate integrity of data measured and transferred from SCADA, to reduce human intervention and to expense national-size applications such as EMS (Energy Management System), WAMS (Wide Area Monitoring System) or WAPS (Wide Area Protection System). This study addresses the issues related to the operation of the smart grid and proposes a new automated approach to achieve this goal. Through applying the proposed system to IEEE 14-bus test electric system, we prove the possibility of the proposed idea.

Measurements get together

This article deals with the synchronized measurement technology that has the potential of becoming the backbone for real-time monitoring system. The secure and reliable operation of modern power systems is an increasingly challenging task due to the ever-increasing demand for electricity, the growing number of interconnections, penetration of variable renewable energy sources, and deregulated energy market conditions. Power companies in different parts of the world are therefore feeling the need for a real-time wide area monitoring, protection, and control (WAMPAC) system. Synchronized measurement technology (SMT) has the potential of becoming the backbone of this system. The major advantages of using SMT are that 1) the measurements from widely dispersed locations can be synchronized with respect to a Global Positioning System (GPS) clock, 2) voltage phase angles can be measured directly, which was so far technically infeasible, and 3) the accuracy and speed of energy management system (EMS) applications increases manifold.

Communication service model for wide area protection system based on IEC 61850

In order to meet the requirements of information exchange varieties and manners in wide area protection system, a communication service model based on IEC 61850 is proposed. This service model can realize communication consistency and cooperation between different types of devices. Furthermore, the communication reliability and time delay performance are guaranteed to meet the requirements of relay protection from the upper layer. Message structure of generic substation event (GSE) and its communication mechanism are discussed. General methods to communicate digital information by generic substation status event (GSSE) and communicate analog sampling information by sampling analog value (SAV) of GSE are proposed.

Wide-Area Protection and Power System Utilization

This paper describes basic principles and philosophy for wide-area protection schemes, also known as remedial action schemes (RAS) or system protection schemes (SPS). In the areas of power system automation and substation automation, there are two parallel trends in different directions: centralization and decentralization. More and more functions are moved from local and regional control centers toward the central or national control center. At the same time we also observe more and more "intelligence" and "decision-power" moving closer toward the actual power system process. We also see a great deal of functional integration, i.e., more and more functionality enclosed in the same hardware. This raises discussions concerning reliability (security and dependability). The main targets for this paper is therefore to: 1) sort out the terminology used in this area; 2) describe different application areas and related requirements; 3) illustrate different design principles-"top-down", "bottom-up", hierarchy, flat, etc., for different applications; and 4) identify similarities and differences between classic equipment protection and system protection-concerning philosophy as well as concerning product and system design. The theme of the paper is on the use of information technology to obtain more flexibility and smartness in power-system controls.

Wide-Area Protection and Emergency Control

System-wide disturbances in power systems are a challenging problem for the utility industry because of the large scale and the complexity of the power system. When a major power system disturbance occurs, protection and control actions are required to stop the power system degradation, restore the system to a normal state, and minimize the impact of the disturbance. In some cases, the present control actions are not designed for a fast-developing disturbance and may be too slow. The report explores special protection schemes and new technologies for advanced, wide-area protection. There seems to be a great potential for advanced wide-area protection and control systems, based on powerful, flexible and reliable system protection terminals, high speed, communication, and GPS synchronization in conjunction with careful and skilled engineering by power system analysts and protection engineers in cooperation.

時刻同期と広帶域通信を用いた広域保護システムの一構成法

時刻同期と広帶域通信を用いた広域保護システムの一構成法

Wide-area current differential backup protection employing broadband communications and time transfer systems

As power systems grow larger, it is becoming difficult to achieve reach and time coordination in backup protection when using distance relays. To cope with those problems, current differential backup protection for a busbar and transmission circuits connected to that busbar on an inter-station or wide-area basis is proposed. The proposed system can operate better than conventional systems with respect to operation time, section selectivity, etc. A system configuration is also proposed to utilize ATM transmission networks and time synchronous systems which make the construction and operation of the proposed wide-area protection system easy and flexible.

Wide-area protection against voltage collapse

A wide-area protection system against long-term voltage collapse was designed, implemented, tested, modified, and commissioned. The system is based on the present SCADA system in southern Sweden, which has been complemented with input signals and equipment to execute action orders from the protection system. Bus voltages from the transmission system, reactive power output from generators connected to the transmission system, and current limiter information from main generators were used as input signals to the wide-area protection system. Actions from the protection system are shunt reactor disconnection, shunt capacitor connection, start of gas turbines, emergency power request from the HVDC connection to Germany, low priority load disconnection, and finally shedding of high priority load.