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

Archiving Black Movements: Shifting Power and Exploring a Community-Centered Approach

With the move towards both critical information literacy and community-centered archives, cultural heritage and information professionals have been called to further interrogate our role as collectors and catalogers of materials. We know that the preservation and description of objects, records, and ephemera ascribe historical meaning, are culturally bound, and impact understanding beyond our lifetime. In this heightened time of social injustice, Black librarians, archivists, and curators are collaborating with community and organizing groups to select and preserve materials related to uprisings in real-time. However, there is a disconnect from the records and items selected for the archives and materials valued by the organizers themselves. There is also a lack of published texts centering the approaches and materials of Black people organizing for their own communities as a part of the archival record with few exceptions. Knowing there is power in the archives, there must be careful consideration to the prioritization and representation of Black communities in their own words. In the following conversations, we thought critically about the provenance and authority of records found on the internet and how archivists should consider materials created by organizers and those created by the community at large. We facilitated three interviews with activists and organizers whose work focuses on the liberation of Black lives globally to both frame and interrogate current archival practices. These interviews explored our archival approach, specifically centering the narratives of the people on the ground. Through these conversations, we discussed the state of organizing and creating digital content as well as how cultural heritage professionals should prioritize the histories of various movements for Black life globally. The interviewees included activists and organizers from the Illinois Chapter of the Black Panther Party (1968-1970s), Black Nashville Assembly, and formerly of Black Lives Matter (2013-present), and End SARS (Special Anti-Robbery Squad) movement (2020-present) in Nigeria. In shaping this conversation, we considered these key questions:  What objects speak to your “work”? What content do you think will help future generations understand past and present movements around Black life? How can cultural heritage professionals determine what is created by BLM, BPP, etc. versus what is contributed by the community-at-large? What does Black liberation look like to you? This article outlines and reimagines archival work as community-based, highly collaborative, and iterative for professionals outside of Black social and political movements. With a focus on intentionality around the communities impacted, individuals involved, and the movements at large, we framed what archival materials are important to Black organizers of our time. With their insight, cultural heritage and archival professionals can create deliberate processes to get direct feedback from the creators themselves for the archives. Overall, this article aims to introduce ways of thinking to decentralize power in archival collections and provide agency to organizers through their own historical record. Pre-print first published online 8/5/202

Application of MPLS-TP for transporting power system protection data

Power utilities are increasingly dependent on the use of communications networks. These networks are evolving to be packet-based, rather than using conventional Time-Division Multiplexing (TDM) technologies. Transporting current differential protection traffic over a packet network is especially challenging, due to the safety-critical nature of protection, the strict requirements for low delay and low asymmetrical delay, and the extensive use of legacy TDM-based protocols. This paper highlights the key technical characteristics of Multi-Protocol Label Switching-Transport Profile (MPLS-TP), and demonstrates its application for transporting current differential protection traffic. A real-time hardware-in-the-loop testing approach has been used to thoroughly validate the technologies in various configurations. It is demonstrated that MPLS-TP technologies can meet the requirements of current differential protection and other, less critical applications. In particular, it is shown that delay and asymmetrical delay can be controlled through the inherent use of bi-directional paths---even when “hitless” link redundancy is configured. The importance of appropriate traffic engineering, clocking schemes, circuit emulation methods is also demonstrated

Automatically detecting and correcting errors in power quality monitoring data

Dependable power quality (PQ) monitoring is crucial for evaluating the impact of smart grid developments. Monitoring schemes may need to cover a relatively large network area, yet must be conducted in a cost-effective manner. Real-time communications may not be available to observe the status of a monitoring scheme or to provide time synchronization, and therefore undetected errors may be present in the data collected. This paper describes a process for automatically detecting and correcting errors in PQ monitoring data, which has been applied in an actual smart grid project. It is demonstrated how to: unambiguously recover from various device installation errors; enforce time synchronization between multiple monitoring devices and other events by correlation of measured frequency trends; and efficiently visualize PQ data without causing visual distortion, even when some data values are missing. This process is designed to be applied retrospectively to maximize the useful data obtained from a network PQ monitoring scheme, before quantitative analysis is performed. This work therefore ensures that insights gained from the analysis of the data - and subsequent network operation or planning decisions - are also valid. A case study of a UK smart grid project, involving wide-scale distribution system PQ monitoring, demonstrates the effectiveness of these contributions. All source code used for the paper is available for reuse

A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30 800 μS/cm (Cl = 11 200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria

Modelling and analysis of asymmetrical latency in packet-based networks for current differential protection application

Current differential protection typically requires symmetrical communications channels—with equal latency in each direction—for correct operation. Conventionally, this has been delivered using protocols such as IEEE C37.94 over a Time-Division Multiplexing (TDM) wide-area network (WAN). Modern packet-based WANs offer improvements in efficiency, flexibility, and cost-effectiveness for utility applications. However, jitter is unavoidable in packet-based networks and, in extreme cases, jitter inevitably results in substantial asymmetrical latency in communications paths. This paper clearly defines how a new source of asymmetry arises due to the use of "de-jitter" buffers, which can jeopardize critical protection services. This is demonstrated using an analytical modelling approach, which precisely quantifies the degree of risk, and through real-time demonstration with actual devices, involving current differential protection over an IP/MPLS WAN. Using a novel method of real-time manipulation of Ethernet traffic to emulate large WANs, the modelling approach has been validated. It is shown how the sensitivity of relays to asymmetry depends on the protection settings and the magnitude of the measured load current. To address the risk of protection maloperation, a new approach for compensating for asymmetrical latency has been comprehensively validated. These developments will be of immediate interest to utilities operating, or migrating to, a packet-based infrastructure

Enabling efficient engineering processes and automated analysis for power protection systems

The reliable operation of power networks depends on the correct configuration of protection systems. These systems involve the coordination of devices across a wide area, each with numerous setting parameters. Presently, protection settings data are typically stored in various vendor-specific proprietary formats, which are difficult to access, interchange, and manipulate automatically. Consequently, the engineering processes for implementing modern protection systems are extremely complex, involving multiple software tools from different vendors. This paper presents a novel solution to these challenges, through the use of the data model provided by the IEC 61850 standard, with the System Configuration description Language (SCL) format to represent protection settings data. The design of a Protection Setting data Conversion Tool (PSCT) that can automatically convert existing settings data between proprietary formats and the SCL-based format is presented. A case study of its implementation demonstrates the benefits of the common representation of protection settings for network operators and other stakeholders. The paper also addresses the challenges that network operators face in migrating to the new approach from existing legacy protection devices and data formats. Adoption of these recommendations and design approaches would shift protection systems from being largely single-vendor solutions to becoming efficient and truly open platforms, capable of supporting future intelligent applications and tools such as automated protection settings validation, diagnostics, and system simulation

A wavelet based synchronized waveform measurement unit algorithm

Power systems with high penetrations of inverter-based resources are increasingly vulnerable to severe disturbances which may manifest as non-stationary voltage and current waveforms, presenting challenges to phasor measurement units which assume quasi-stationary conditions. Time synchronized, high-resolution, waveform measurements have emerged as a solution to accurately monitor emerging system dynamics. This paper proposes a synchronized waveform measurement unit algorithm to detect and characterize transient and dynamic phenomena present in synchronized waveform measurements. The proposed method utilizes the discrete wavelet packet transform to represent non-sinusoidal transients, while the adaptive empirical wavelet transform is applied to extract the fundamental and possible oscillation components. Finally, dynamic phasor extraction is performed via the Hilbert transform. The performance of the proposed algorithm is evaluated using synthetic test signals and compared to a phasor measurement unit algorithm using a goodness of fit metric. The results indicate that the proposed method produces an accurate and sparse representation of the underlying signal dynamics. The proposed method can potentially reduce communication requirements associated with high resolution synchronized waveform measurements, thus enabling real-time synchronized waveform-based applications