Mitalkumar G. Kanabar

Opportunities and challenges of wireless communication technologies for smart grid applications

Two-way seamless communication is the key aspect of realizing the vision of smart grid. There are several standardized wired and wireless communication technologies available for various smart grid applications. With the recent growth in wireless communication, it can offer standardized technologies for wide area, metropolitan area, local area, and personal area networks. Moreover, wireless technologies not only offer significant benefits over wired, such as including low installation cost, rapid deployment, mobility, etc., but also more suitable for remote end applications. Several activities are going on to explore specific applications of these technologies in smart grid environment. This paper presents various smart grid applications achieved through standardized wireless communication technologies, e.g. IEEE 802.11 based wireless LAN, IEEE 802.16 based WiMAX, 3G/4G cellular, ZigBee based on IEEE 802.15, IEEE 802.20 based MobileFi, etc. Moreover, challenges related to each wireless communication technologies have been discussed in brief.

Performance of IEC 61850-9-2 Process Bus and Corrective Measure for Digital Relaying

International Electrotechnical Commission (IEC) standard 61850 proposes the Ethernet-based communication networks for protection and automation within the power substation. Major manufacturers are currently developing products for the process bus in compliance with IEC 61850 part 9-2. For the successful implementation of the IEC 61850-9-2 process bus, it is important to analyze the performance of time-critical messages for the substation protection and control functions. This paper presents the performance evaluation of the IEC 61850-9-2 process bus for a typical 345 kV/230 kV substation by studying the time-critical sampled value messages delay and loss by using the OPNET simulation tool in the first part of this paper. In the second part, this paper presents a corrective measure to address the issues with the several sampled value messages lost and/or delayed by proposing the sampled value estimation algorithm for any digital substation relaying. Finally, the proposed sampled value estimation algorithm has been examined for various power system scenarios with the help of PSCAD/EMTDC and MATLAB simulation tools.

Evaluation of communication technologies for IEC 61850 based distribution automation system with distributed energy resources

This paper presents the study of different communication systems between IEC 61850 based distribution substation and distributed energy resources (DERs). Communication networks have been simulated for a typical distribution automation system (DAS) with DERs using OPNET software. The simulation study shows the performance of wired and wireless communication systems for different messages, such as GOOSE and measured (metered) values between DAS and DERs. A laboratory set-up has been implemented using commercial relay and communication devices for evaluating the performance of GOOSE messages, using wired and wireless physical medium. Finally, simulation and laboratory results are discussed in detail.

Reliability and availability analysis of IEC 61850 based substation communication architectures

To achieve interoperability among multi-vendor substation automation devices, international electro-technical commission (IEC) has published IEC 61850 standard for communication networks within power substations. This standard specifies the communication systems based on Ethernet networks for the substation automation systems (SAS). Ethernet provides flexibility in terms of configuring various architectures with the help of Ethernet switches. However, the reliability and availability of the applicable Ethernet architectures need to be analyzed before they are implemented for critical applications in substations. This paper presents the reliability and availability evaluation of the practical Ethernet switch architectures using reliability block diagram (RBD) approach. The reliability block diagrams have been built for the intra-bay and inter-bay communications considering a typical transmission substation. Further, the reliability and availability of the practical Ethernet architectures have been compared and some suggestions have been made using the final results.

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.

Reviewing smart grid standards for protection, control, and monitoring applications

Two-way seamless communication is the key aspect of realizing the vision of smart grid. Currently, several smart grid standardization efforts are underway in US and Europe. National Institute of Standard and Technology (NIST) has prioritized several process of standardization and harmonization of existing standards with the new developments. Power system protection, control and monitoring (PCM) are one of the most time critical applications for power utilities in the smart grid environment. This paper present review of available standards for PCM and discusses their applications and current developments. Moreover, the paper also highlights the challenges related to smart grid standardization in brief.

Configuration and performance testing of IEC 61850 GOOSE

The IEC 61850 standard part 8-1 proposes Generic Object Oriented Substation Event (GOOSE) message for time critical applications over the Ethernet network. In order to cover the wide range of applications and achieve flexibility in implementation, GOOSE messages are kept generic in the standard. However, this flexibility leads to configuration problem achieving multi-vendor interoperability. Therefore, some efforts have been carried out in this work to present a systematic GOOSE configuration approach, as well as, verification and performance testing of the GOOSE. First part of this paper configuration of Ethernet switched network, including IEEE 1588 based time synchronization, Rapid Spanning Tree Protocol (RSTP), and IEEE 802.1Q based Quality of Services (QoS). In the second part, the paper leads to step-by-step configuration process comprising IEC 61850 data modeling, datasets of GOOSE within individual IEDs, and system integration of GOOSE. Finally, the verification of configured GOOSE messages is presented using network analyzer tools, and performance testing time delay) over the network is carried out for various network scenarios.

Packet scheduling of GOOSE messages in IEC 61850 based substation intelligent electronic devices (IEDs)

IEC61850 is a new international standard for communication networks and systems in substations that defines different message types based on their transfer time requirements. In IEC61850-based Substation Automation systems (SAS), Generic Object Oriented Substation Event (GOOSE) messages are used for conveying time critical information between the protection and control devices. In a switched SAS network architecture the switches are provided with a strict priority queuing discipline to provide higher priority for the real-time messages. However, the message scheduling inside the intelligent electronic devices is first in first out. The non-critical messages can add to the queuing delay of GOOSE messages during a heavy traffic congestion period. In this paper, different packet scheduling algorithms have been applied for SAS IEDs using an OPNET simulation tool. A sample SAS network is constructed based on IEC61850 specifications, and the effect of the different packet scheduling schemes in IEDs on GOOSE message delays is analyzed in detail. The comparison of these different packet scheduling schemes have been discussed from the results of the sample SAS.

A review of smart grid standards for protection, control, and monitoring applications

Two-way seamless communication is the key aspect of realizing the vision of smart grid. Currently, several smart grid standardization efforts are underway in US and Europe. National Institute of Standard and Technology (NIST) has prioritized several process of standardization and harmonization of existing standards with the new developments. Power system protection, control and monitoring (PCM) are one of the most time critical applications for power utilities in the smart grid environment. This paper present review of available standards for PCM and discusses their applications and current developments. Moreover, the paper also highlights the challenges related to smart grid standardization in brief.

Optimizing Wide Area Measurement System architectures with advancements in Phasor Data Concentrators (PDCs)

Large scale deployment of Wide Area Measurement System (WAMS) is underway at several major power utilities around the globe. This is influencing several activities and discussions at international standard associations (IEEE/IEC) and meetings (NASPI/CIGRE/PSRC) to devise the effective but optimum WAMS architecture. This paper presents some of the recent advancements in Phasor Data Concentrator (PDC) technology to achieve fit-to-purpose WAMS architecture. The presented guidelines can be used to reduce the network bandwidth requirements as well as PDC latency. In addition, this paper also discusses various desired features to handle communication network contingencies, e.g. GPS fail, loss of PMU communication, PMU streams with different data rates and different latency; lost synchrophasor data; diagnostics and their notification at upstream devices, etc.