Dependability Optimization of Process-level Protection in an IEC-61850-Based Substation

International audiencePower substations are intensively renovated toward using information and communication technologies such as object oriented modeling and Ethernet networks. In the last two decades, Substation automation systems used capabilities of network communication services adopted from sophisticated international standardization such as IEC 61850. Distributed safety related functions take advantage of these technologies to protect the process-level equipment. Substation devices such as intelligent electronic devices, measurement units and circuit breaker controllers, with new capabilities, i.e. enabling IEC 61850, are integrated to build the protection and control functions that form the safety-related system. The objective of this research is to evaluate quantitatively the dependability for transformer protection architectures in the bay level.Safety integrity levels model, described in both IEC 62061 and IEC 61508, gives measurements for safety integrity levels according to the probability of failure. The determination of these levels is an approach to estimate system dependability

Standardization of power system protection settings using IEC 61850 for improved interoperability

One of the potential benefits of smart grid development is that data becomes more open and available for use by multiple applications. Many existing protection relays use proprietary formats for storing protection settings. This paper proposes to apply the IEC 61850 data model and System Configuration description Language (SCL), which are formally defined, to represent protection settings. Protection setting files in proprietary formats are parsed using rule-based reasoning, mapped to the IEC 61850 data model, and exported as SCL files. An important application of using SCL-based protection setting files is to achieve protection setting interoperability, which could bring multiple compelling benefits, such as significantly streamlining the IED configuration process and releasing utilities from being “locked in” to one particular vendor. For this purpose, this paper proposes a uniform configuration process for future IEDs. The challenges involved in the implementation of the proposed approach are discussed and possible solutions are presented

An Investigation into the testing and commissioning requirements of IEC 61850 Station Bus Substations

The emergence of the new IEC 61850 standard generates a potential to deliver a safe, reliable and effective cost reduction in the way substations are designed and constructed. The IEC 61850 Station Bus systems architecture for a substation protection and automation system is based on a horizontal communication concept replicating what conventional copper wiring performed between Intelligent Electronic Devices (IED’s). The protection and control signals that are traditionally sent and received across a network of copper cables within the substation are now communicated over Ethernet based Local Area Networks (LAN) utilising Generic Object Oriented Substation Event (GOOSE) messages. Implementing a station bus system generates a substantial change to existing design and construction practices. With this significant change, it is critical to develop a methodology for testing and commissioning of protection systems using GOOSE messaging. Analysing current design standards and philosophies established a connection between current conventional practices and future practices using GOOSE messaging at a station bus level. A potential design of the GOOSE messaging protection functions was implemented using the new technology hardware and software. Identification of potential deviations from the design intent, examination of their possible causes and assessment of their consequences was achieved using a Hazard and Operability study (HAZOP). This assessment identified the parts of the intended design that required validating or verifying through the testing and commissioning process. The introduction of a test coverage matrix was developed to identify and optimise the relevant elements, settings, parameters, functions, systems and characteristics that will require validating or verifying through inspection, testing, measurement or simulations during the testing and commissioning process. Research conducted identified hardware and software that would be utilised to validate or verify the IEC 61850 system through inspection, testing, measurement or simulations. The Hazard and Operability study (HAZOP) has been identified as an effective, structured and systematic analysing process that will help identify what hardware, configurations, and functions that require testing and commissioning prior to placing a substation using IEC 61850 Station bus GOOSE messaging into service. This process enables power utilities to understand new challenges and develop testing and commissioning philosophies and quality assurance processes, while providing confidence that the IEC 61850 system will operate in a reliable, effective and secure manner

Power Systems Monitoring and Control using Telecom Network Management Standards

Historically, different solutions have been developed for power systems control and telecommunications network management environments. The former was characterized by proprietary solutions, while the latter has been involved for years in a strong standardization process guided by criteria of openness. Today, power systems control standardization is in progress, but it is at an early stage compared to the telecommunications management area, especially in terms of information modeling. Today, control equipment tends to exhibit more computational power, and communication lines have increased their performance. These trends hint at some conceptual convergence between power systems and telecommunications networks from a management perspective. This convergence leads us to suggest the application of well-established telecommunications management standards for power systems control. This paper shows that this is a real medium-to-long term possibility

Translating proprietary protection setting data into standardized IEC 61850 format for protection setting validation

For smart grid development, one of the key expectations is that the data should be accessible to and readily interpreted by different applications. Presently, protection settings are represented using proprietary parameters and stored in various file formats. This makes it very difficult for computer applications to manipulate such data directly. This paper introduces a process that translates the proprietary protection setting data into IEC 61850 standardised format and saves the data as System Configuration description Language (SCL) files. A code generation process that allows rapid implementation of the translation process is proposed. Among various applications, the paper demonstrates how such a translation process and generated SCL files can facilitate the development of an intelligent system for protection setting error detection and validation

An open platform for rapid-prototyping protection and control schemes with IEC 61850

Communications is becoming increasingly important to the operation of protection and control schemes. Although offering many benefits, using standards-based communications, particularly IEC 61850, in the course of the research and development of novel schemes can be complex. This paper describes an open-source platform which enables the rapid prototyping of communications-enhanced schemes. The platform automatically generates the data model and communications code required for an intelligent electronic device to implement a publisher-subscriber generic object-oriented substation event and sampled-value messaging. The generated code is tailored to a particular system configuration description (SCD) file, and is therefore extremely efficient at runtime. It is shown here how a model-centric tool, such as the open-source Eclipse Modeling Framework, can be used to manage the complexity of the IEC 61850 standard, by providing a framework for validating SCD files and by automating parts of the code generation process. The flexibility and convenience of the platform are demonstrated through a prototype of a real-time, fast-acting load-shedding scheme for a low-voltage microgrid network. The platform is the first open-source implementation of IEC 61850 which is suitable for real-time applications, such as protection, and is therefore readily available for research and education

Evaluation of Time-Critical Communications for IEC 61850-Substation Network Architecture

Present-day developments, in electrical power transmission and distribution, require considerations of the status quo. In other meaning, international regulations enforce increasing of reliability and reducing of environment impact, correspondingly they motivate developing of dependable systems. Power grids especially intelligent (smart grids) ones become industrial solutions that follow standardized development. The International standardization, in the field of power transmission and distribution, improve technology influences. The rise of dedicated standards for SAS (Substation Automation Systems) communications, such as the leading International Electro-technical Commission standard IEC 61850, enforces modern technological trends in this field. Within this standard, a constraint of low ETE (End-to-End) latency should be respected, and time-critical status transmission must be achieved. This experimental study emphasis on IEC 61850 SAS communication standard, e.g. IEC 61850 GOOSE (Generic Object Oriented Substation Events), to implement an investigational method to determine the protection communication delay. This method observes GOOSE behaviour by adopting monitoring and analysis capabilities. It is observed by using network test equipment, i.e. SPAN (Switch Port Analyser) and TAP (Test Access Point) devices, with on-the-shelf available hardware and software solutions

Demonstration of adaptive overcurrent protection using IEC 61850 communications

This paper contains a description of an adaptive protection scheme that has been implemented and demonstrated in a hardware in the loop simulation environment using commercially available protection hardware and IEC 61850 communications.The implementation is based on an actual 11kV system which includes distributed generation and network automation. IEC 61850 communications offers several benefits for the implementation of adaptive protection, but also presents some limitations which are discussed in the paper. An alternative approach to overcome a number of the limitations is also presented

Laboratory testing of the communication based protection relays

The proper operation of control and protection applications in Substation Automation System (SAS) demands very high-speed and reliable communications that has being achieved by using IEC 61850. Moreover, the practical implementation and testing of protection scheme requires a communication system that can be conventional or high-speed peer-to-peer communication. This paper presents the evaluation of the performance advantage of GOOSE (Generic Object Oriented Substation Event) message over its conventional hard-wired counterpart for the same relays protection