Process Bus Communication Research Articles

Hardware Development and Interoperability Testing of a Multivendor-IEC-61850-Based Digital Substation

Substations are becoming increasingly reliant on international electrotechnical commission (IEC)-61850-enabled devices. However, device compatibility with these standards does not guarantee interoperability when devices are taken from different manufacturers. If interoperability of multivendor devices can be achieved, then power utilities will be in a position to implement multivendor devices in substations. The study here presents the development and testing of a digital substation test platform that incorporates devices from different manufacturers. The process bus communication and protection operation of the intelligent electronic devices (IEDs) were tested to validate device interoperability. The testbed was tested for two IED process bus communications, generic object-oriented substation event (GOOSE) and sampled measured value (SMV). The GOOSE is travelling between IED to IED with an end-to-end (ETE) delay of 2 ms and the SMV read by the IEDs are the same as the injected real-time substation inputs 220 kV and 1 kA. Three IED protection studies (overcurrent, earth fault, and overvoltage) were performed, and IED response curves were obtained. In addition, data monitoring and client–server communications were studied using installed software tools. The testbed configuration in this study has faced some real-time challenges regarding differences in device edition, device firmware, and ethernet switch due to its multivendor approach. All the mentioned configuration issues were resolved in this study with successful testing and validation of the testbed. The study of this testbed will provide solutions to the problems associated with a multivendor system faced by substation engineers and will help them in opting for multivendor installations. This system can be extended in the future by installing more multivendor devices with complex network topology and a SCADA system.

Impact and Vulnerability Analysis of IEC61850 in Smartgrids Using Multiple HIL Real-Time Testbeds

Due to the increasing use of smart components in smart grids, interoperability among them is a crucial aspect to address. IEC61850 is a communication standard that has been already used in substations because of its instant data transfer and the ability to enable data exchange between a variety of smart energy-related digital technologies. This article studies the application of the communication protocols defined by the IEC61850 standard in Intelligent Electronic Devices (IEDs) by using a prototype testbed architecture running on a real-time digital device. The goal of this activity is to study the impact of smart simulations and the vulnerability in terms of cyber-security. This testbed includes the supervisor, the substation bus, and the process bus communication layer creating a local network exchanging data at distinct levels. Different fault protection scenarios are discussed using both physical and emulated IEDs, and the communication protocols implemented in each scenario are explained showing that additional delays are introduced. In the first two scenarios, the operation of the testbed using physical versus emulated IEDs is analyzed and compared, ensuring the robustness of this methodology in situations where the use of a physical IED would be unfeasible. In these scenarios, the functionality and robustness of the protection mechanisms and communication protocols are confirmed. In the third scenario vulnerability of smart grids that use IEC61850 as their primary communication protocol to data injection attacks is studied. Sniffing the local network, packets are captured and monitored. Spoofed data with the same structure are injected into the network to conduct false data injection attacks on the supervisory unit. Vulnerability to cyber attacks of the IEC61850 protocol in specific situations is shown.

Real-Time Performance and Security of IEC 61850 Process Bus Communications

Modern power-network communications are based on the IEC 61850 series standards. In this paper, we investigate the real-time performance and the vulnerabilities and attack scenarios at the sensor level communication networks more precisely on Sampled Measured Value protocol. The approach jointly evaluates the communication protocol, network topology and impact on electrical protection functions. We test the practical feasibility of the attacks on an experimental workbench using real devices in a hardware-in-the-loop setup. The tests are conducted on the two high-availability automation networks currently used in IEC 61850 process bus communications: Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR)

Implementation of Secure Sampled Value (SeSV) Messages in Substation Automation System

IEC61850 is the mainstream of the development for substation automation. This paper presents a practical consideration and analysis for implementing a secure sampled measured value (SeSV) message in substation automation system. Due to the lack of security features in the standard, IEC Working Group 15 of Technical Committee 57 published IEC62351 on security for IEC61850 profiles. However, the use of authentication methods for SV based on IEC62351 standards are still not integrated, and computational capabilities and performance are not validated and tested with commercial grade equipment. Hence, this paper shows the performance of security feature enabled SeSV packets transmitted between protection and control devices by appending a message authentication code (MAC) to the extended IEC61850 packets. A prototype implementation on a low cost commodity embedded system has proved that the MAC-enabled SV message can fully secure the process bus communication in the digital substation with negligible time delay.

Real Time Operation of IEC 61850 Based Digital Substation

The advancement in technologies applied on substation studies are leading towards substation automation systems (SAS). In SAS network interoperability of substation devices is an important factor that needs good media of communication. IEC 61850 protocol has a greater role in device communications and protection functions of an integrated system. Also this standard can address the problem of interoperability of devices from various vendors. With the implementation of IEC 61850 standards in SAS networks, integration of latest devices like, intelligent electronic devices (IEDs), analog merging units (AMUs) and Ethernet networks are becoming possible. IEC 61850 standards will upgrade a conventional substation model into Digital Substation providing IEDs and modern substation devices are getting installed. In this paper IEC 61850 standard with its various operational levels have been studied for basic understanding of the protocol. A digital substation model with operational architecture has been shown and its various process bus communication messages have been discussed. To establish the concept of interoperability of subsation devices in a substaion model, a digital substation laboratory model has been developed here with IEC 61850 standard implementation. Real time analysis of protection functions with process bus communications of the substation model have been executed. The study of IEC 61850 standard and digital substation with its real time hardware test results will give the reader a clear idea about digital substations, substation devices interoperability operations and protection functions. This implementation and application of IEC standards in substation communication and protection functions can get used effectively in future for testing some other network topology.

Analysis of IEC 61850-9-2LE Measured Values Using a Neural Network

Process bus communication has an important role to digitalize substations. The IEC 61850-9-2 standard specifies the requirements to transmit digital data over Ethernet networks. The paper analyses the impact of IEC 61850-9-2LE on physical protections with (analog-digital) input data of voltage and current. With the increased interaction between physical devices and communication components, the test proposes a communication analysis for a substation with the conventional method (analog input) and digital method based on the IEC 61850 standard. The use of IEC 61850 as the basis for smart grids includes the use of merging units (MUs) and deployment of relays based on microprocessors. The paper analyses the merging unit's functions for relays using IEC 61850-9-2LE. The proposed method defines the sampled measured values source and analysis of the traffic. By using neural net pattern recognition that solves the pattern recognition problem, a relation between the inputs (number of samples/ms—interval time between the packets) and the source of the data is found. The benefit of this approach is to reduce the time to test the merging unit by getting the feedback from the merging unit and using the neural network to get the data structure of the publisher IED. Tests examine the GOOSE message and performance using the IEC standard based on a network traffic perspective.

Novel Technique for a Dynamically State Estimation In Contemporary Power Substations

This paper presents implementation and performance evaluation of states estimation in contemporary power substations. The estimation is based on streamed IEC 61850-9-2 Sampled Measured Values (SMV) that provide by the Merging Units (MUs) at process level (Level-0) . With the reference to the most challenging problem of tracking dynamic phenomena, the Unsented Kalman Filtering (UKF) is proposed to be used in the centralized computation of synchrophasors in a substation to enhance the power system state estimation. Such system can supersede the current Phasor Measurement Units (PMUs) and mitigating the problems of installing new dedicated PMUs due to the high cost. TrueTime, a Matlab/Simulink-based simulator that developed by ABB Corporate Research Group, Sweden to emulate the IEC 61850-9-2 process bus communication has been used for the simulation. In this simulation, evaluating the effects of latency introduced by the communication network, the offset and the clock drift at each sensor node (MU) on simulated Dynamic Phasor Estimation performance were given more attention. Representative results in evaluating the Phasors computation performance are presented in the paper.

Simulation and testing of the over-current protection system based on IEC 61850 Process-Buses and dynamic estimator

Abstract This paper presents a successful real-time simulation and testing of the over-current protection system based on IEC 61850-9-2 Sampled Measured Values communication and a dynamic estimator using a simulator of the real-time environment. The TrueTime software and the Matlab Simulink had been integrated into the real-time environment simulator for testing real-time performance of the IEC 61850 Process-Bus and the protection system. Performance of the IEC 61850 Process-Bus communications can be affected by many factors like, bandwidth and cable length. These factors will affect the measurements provided to protective relays through Process-Bus due to delay or loss of some Sampled Measured Values. The purpose of the tests in the real-time environment simulator is to show how an over-current protection relay would react to operation conditions of the IEC 61850 Process-Bus. Understanding how a physical protection system can respond to IEC 61850 Process-Bus communication will give engineers the confidence that is needed to assure that the system under consideration will behave as acceptable.

Design and Performance Testing of a Multivendor IEC61850–9-2 Process Bus Based Protection Scheme

The deployment of IEC61850-9-2 process bus increases the possibilities that new and refurbished substations will be based on the use of Ethernet communication networks with free allocation of Protection and Control functions. The design and performance testing of a multivendor prototype protection scheme based on the process bus for use in a mesh transmission substation is presented. A practical test setup is developed to evaluate the performance of the protection scheme, including interoperability between different manufacturers, degree of maturity, robustness, and possible benefits. This integrates network analysis software, test sets, conventional hardwired and IEC61850-9-2LE protection Intelligent Electronic Devices, Merging Units, Ethernet Switches, Fiber Optic communications and an IEC61850 process bus. The worst case scenario of traffic based on the current 100 Mbps network is created and the system responses investigated. Recommendations for process bus communication requirements are presented to avoid the degradation of system performance.

Impact of IEC 61850-9-2 Standard-Based Process Bus on the Operating Performance of Protection IEDS: Comparative Study

IEC 61850-9-2 is an international substation automation standard that proposes a Process Bus communication network between process level equipment and bay level Intelligent Electronic Devices (IEDs) used for power systems protection and control.This paper considers the drive towards the use of IEC 61850-9-2 Process Bus in substations. The impact of the IEC 61850-9-2 standard on the operating performance of protection IEDs in terms of dependability, security, and operating speed is considered. A lab-scale hardware-in-the-loop experiment involving the Real-Time Digital Simulator (RTDS), IEC 61850-9-2 protection IED based on Sampled Values (SV) inputs, conventional hardwired protection IED, GPS satellite clock, and industrial network switches is implemented and used for the investigations.The experiments are directed towards the comparison of the performance of the distance protection function of the two protection IEDs when subjected to various fault types at various fault locations, fault resistances, and fault inception angles, with different Source Impedance Ratios (SIRs). Furthermore, the possible impact of random noise/delay on the protection functions of the IEC 61850-9-2 Process Bus based protection IED is investigated. The stability and security of the protection function of the protection IED based on SVs generated from the GTNET-SV card of the RTDS is investigated and compared to that of the IED based on conventional hardwired CTs and VTs.

Dynamic Simulation and Test of IEC 61850-9-2 Process Bus Applications

IEC 61850-9-2 proposes the process bus communication for protection and automation within substations. The actual performance of process bus such as real-time, security and reliability are of concern, when transmission of sample values and trip signals over the same network. This paper presents the establishment of a dynamic simulation test platform, in order to facilitate the test of protection schemes over the process bus. An example is given to demonstrate that incorrect switch configuration, message priority tagging, and the volumes of traffic on the network may have an impact on the real time and reliability of the signals to be delivered.

Laboratory Investigation of IEC 61850-9-2-Based Busbar and Distance Relaying With Corrective Measure for Sampled Value Loss/Delay

After successful implementation of IEC 61850-8-1-based GOOSE at several power substations worldwide, major protective device vendors are currently developing interoperable products for IEC 61850-9-2-based time-critical sampled value (SV) messages over the digital process bus. Unlike GOOSE, the same SV message is not repeated several times and, therefore, it is important to analyze the impact of SV loss or delay on protection functions. This paper presents the hardware implementation of a typical IEC 61850-9-2-based process bus communication network for digital protection systems to investigate the proposed corrective measure for SV loss/delay. For the detailed testing, various process bus devices (e.g. protection intelligent electronic devices (IEDs), merging units (MUs), etc.) are developed over industrial embedded systems with a hard-real-time platform. The SV estimation algorithm is implemented as a part of bus differential and transmission-line distance protection IEDs, and it is tested for various SV loss/delay scenarios and power system fault conditions.

96/05040 Fibre optics standardisation

IEC 61850-9-2 is an international substation automation standard that proposes a Process Bus communication network between process level equipment and bay level Intelligent Electronic Devices (IEDs) used for power systems protection and control.This paper considers the drive towards the use of IEC 61850-9-2 Process Bus in substations. The impact of the IEC 61850-9-2 standard on the operating performance of protection IEDs in terms of dependability, security, and operating speed is considered. A lab-scale hardware-in-the-loop experiment involving the Real-Time Digital Simulator (RTDS), IEC 61850-9-2 protection IED based on Sampled Values (SV) inputs, conventional hardwired protection IED, GPS satellite clock, and industrial network switches is implemented and used for the investigations.The experiments are directed towards the comparison of the performance of the distance protection function of the two protection IEDs when subjected to various fault types at various fault locations, fault resistances, and fault inception angles, with different Source Impedance Ratios (SIRs). Furthermore, the possible impact of random noise/delay on the protection functions of the IEC 61850-9-2 Process Bus based protection IED is investigated. The stability and security of the protection function of the protection IED based on SVs generated from the GTNET-SV card of the RTDS is investigated and compared to that of the IED based on conventional hardwired CTs and VTs.

96/05036 An efficient approach to identify and integrate demand-side management on electric utility generation planning

IEC 61850-9-2 is an international substation automation standard that proposes a Process Bus communication network between process level equipment and bay level Intelligent Electronic Devices (IEDs) used for power systems protection and control.This paper considers the drive towards the use of IEC 61850-9-2 Process Bus in substations. The impact of the IEC 61850-9-2 standard on the operating performance of protection IEDs in terms of dependability, security, and operating speed is considered. A lab-scale hardware-in-the-loop experiment involving the Real-Time Digital Simulator (RTDS), IEC 61850-9-2 protection IED based on Sampled Values (SV) inputs, conventional hardwired protection IED, GPS satellite clock, and industrial network switches is implemented and used for the investigations.The experiments are directed towards the comparison of the performance of the distance protection function of the two protection IEDs when subjected to various fault types at various fault locations, fault resistances, and fault inception angles, with different Source Impedance Ratios (SIRs). Furthermore, the possible impact of random noise/delay on the protection functions of the IEC 61850-9-2 Process Bus based protection IED is investigated. The stability and security of the protection function of the protection IED based on SVs generated from the GTNET-SV card of the RTDS is investigated and compared to that of the IED based on conventional hardwired CTs and VTs.