Intelligent monitoring of the health and performance of distribution automation

With a move to 'smarter' distribution networks through an increase in distribution automation and active network management, the volume of monitoring data available to engineers also increases. It can be onerous to interpret such data to produce meaningful information about the health and performance of automation and control equipment. Moreover, indicators of incipient failure may have to be tracked over several hours or days. This paper discusses some of the data analysis challenges inherent in assessing the health and performance of distribution automation based on available monitoring data. A rule-based expert system approach is proposed to provide decision support for engineers regarding the condition of these components. Implementation of such a system using a complex event processing system shell, to remove the manual task of tracking alarms over a number of days, is discussed

Impact Assessment of Hypothesized Cyberattacks on Interconnected Bulk Power Systems

The first-ever Ukraine cyberattack on power grid has proven its devastation by hacking into their critical cyber assets. With administrative privileges accessing substation networks/local control centers, one intelligent way of coordinated cyberattacks is to execute a series of disruptive switching executions on multiple substations using compromised supervisory control and data acquisition (SCADA) systems. These actions can cause significant impacts to an interconnected power grid. Unlike the previous power blackouts, such high-impact initiating events can aggravate operating conditions, initiating instability that may lead to system-wide cascading failure. A systemic evaluation of "nightmare" scenarios is highly desirable for asset owners to manage and prioritize the maintenance and investment in protecting their cyberinfrastructure. This survey paper is a conceptual expansion of real-time monitoring, anomaly detection, impact analyses, and mitigation (RAIM) framework that emphasizes on the resulting impacts, both on steady-state and dynamic aspects of power system stability. Hypothetically, we associate the combinatorial analyses of steady state on substations/components outages and dynamics of the sequential switching orders as part of the permutation. The expanded framework includes (1) critical/noncritical combination verification, (2) cascade confirmation, and (3) combination re-evaluation. This paper ends with a discussion of the open issues for metrics and future design pertaining the impact quantification of cyber-related contingencies

International White Book on DER Protection : Review and Testing Procedures

This white book provides an insight into the issues surrounding the impact of increasing levels of DER on the generator and network protection and the resulting necessary improvements in protection testing practices. Particular focus is placed on ever increasing inverter-interfaced DER installations and the challenges of utility network integration. This white book should also serve as a starting point for specifying DER protection testing requirements and procedures. A comprehensive review of international DER protection practices, standards and recommendations is presented. This is accompanied by the identifi cation of the main performance challenges related to these protection schemes under varied network operational conditions and the nature of DER generator and interface technologies. Emphasis is placed on the importance of dynamic testing that can only be delivered through laboratory-based platforms such as real-time simulators, integrated substation automation infrastructure and fl exible, inverter-equipped testing microgrids. To this end, the combination of fl exible network operation and new DER technologies underlines the importance of utilising the laboratory testing facilities available within the DERlab Network of Excellence. This not only informs the shaping of new protection testing and network integration practices by end users but also enables the process of de-risking new DER protection technologies. In order to support the issues discussed in the white paper, a comparative case study between UK and German DER protection and scheme testing practices is presented. This also highlights the level of complexity associated with standardisation and approval mechanisms adopted by different countries

Development Needs in Automatic Fault Location, Isolation and Supply Restoration of MicroSCADA Pro DMS600

Tightened reliability requirements for the electricity distribution are causing distribution system operators to improve the quality of supply by renovating the network. To achieve a weather-proof distribution network by the end of year 2028, major investments must be made by means of replacing overhead lines with cables and increasing the level of automation in the network. Since the renovation process is rather slow and expensive, DSOs must obtain cost savings in distribution network operation by utilizing existing network automation more efficiently. One of the main solutions is to automatize the fault management and thereby reduce outage duration experienced by the customer. Traditional fault management comprises the co-operation of the network control center and field crews working along the distribution network. An increasing amount of network automation, such as remote-controlled disconnectors, sectionalizing reclosers and fault detectors, is improving the response time of medium network faults when the operator can isolate the fault remotely from the control center. However, multiple simultaneous faults in major electricity disruption can cause personnel of the control center to be overburdened with fault handling and dispatching field crews. Therefore, automatic Fault Location, Isolation, and supply Restoration (FLIR) functionality is considered as a beneficial tool to assist the network operator. While the FLIR performs the first steps of fault management, operator is freed to conduct the operation of field crews repairing failures. MicroSCADA Pro is a product family for electricity distribution control and supervisory by ABB. The current version of MicroSCADA Pro DMS600 4.5 already includes functionality for automatic fault isolation and supply restoration, but it is not used by any DSOs due to functional imperfections. The current fault detection, isolation and supply restoration (FDIR) functionality requires an exact fault location inferred by fault current measurements or fault indicator operations and therefore, it can rarely operate due to lack of initial data. To achieve an efficient operation, a trial switching sequence must be introduced as part of the existing functionality. The method of trial switching is normally used by the operator when fault cannot be located according to measurements and indications. A basic principle of the trial switchings is to divide faulty feeder into minor sections and close the substation circuit breaker against the suspected fault. This is continued until the circuit breaker trips and the fault has been located and isolated into a single disconnector zone. The research for this thesis was carried out by interviews for Finnish DSOs to gather requirements and restrictions for the FLIR functionality. The main objective of the interview process was to familiarize the fault management process of a network control center operator, so as human-like operation of the FLIR could be obtained. Interviews gathered the most important development needs and possible restrictions to ensure the most fluent operation between automation and the network control center operators. For example, automation may not be wanted to restore supply from adjacent feeders during major disturbance, since multiple fault can occur and cause also backup feeder to trip and increase the faulty area. Automatic functionality should not also disturb the operation of network control center, and thus separate fault handling areas should be determined for FLIR to operate

Improving the reliability performance of medium voltage networks

The aim of this dissertation is to investigate alternative, more reliable and cost effective ways of improving the reliability performance of medium voltage networks. Customers are mainly affected by faults on the distribution MV network, to which, consequently, we have to pay particular attention. A major requirement on electricity supply systems is high supply reliability for the customer which is mainly determined by the distribution networks. Power system reliability is an essential factor in the quality of supply and is directly related to the number and duration of outages. By analysing the power system properly, the weaknesses will then be identified and improvements can be introduced to minimise the occurrence of outages. A decrease in the outage rate will result in an improvement in reliability and quality of supply of the distribution MV network. The dissertation focuses on improving the network management by increasing the level of network automation and control which improves the operating efficiency of medium voltage distribution networks. Steps are shown how to equip the network according to progressive investment capability, from Fault Path Indicators (FPIs) and remote control Pulseclosing technologies to automatic FuseSavers and Tripsavers used in a feeder automation scheme to minimise the number of disturbances and the outage durations experienced when they occur. The results of a study analysing the impact of different intelligent automation solutions on the reliability performance of Medium Voltage distribution networks are presented in the dissertation. The respective system topologies are modelled and the resulting system reliability performance is determined by reliability calculations such as the SAIDI and SAIFI values. The results show that the distribution automation technologies can have a very significant impact on both the SAIDI and SAIFI performance of the systems. Further, selected details related to the implementation of such intelligent automation schemes are presented in this dissertation

Emerging technologies and future trends in substation automation systems for the protection, monitoring and control of electrical substations

Tese de Mestrado Integrado. Engenharia Electrotécnica e de Computadores (Automação). Faculdade de Engenharia. Universidade do Porto. 201

Integrating Low Voltage Distribution Systems to Distribution Automation

The aim of this thesis is to define and study the key elements and the main characteris-tics of the integration of the low voltage (LV) distribution systems to distribution auto-mation (DA). The key elements are defined by studying the development of essential systems in LV distribution networks as well as by studying the development of the net-works by way of evolution phases. The key elements and the main characteristics of the integration to DA are illustrated by a certain model of a LV distribution network under its development. For a start DA is reviewed by generally used functions and by technologies. The review includes the data and the information systems and in addition the communication net-works are studied generally. Thereafter the main elements of LV distribution networks are presented and their evolution visions are introduced. The main elements comprises of the distribution network, distributed generation, smart energy metering, electric vehicles and energy storages. The approach to the integration is the evolution of LV distribution networks, so four main evolution phases are introduced; traditional, boom of distributed generation, mi-crogrid and intelligent microgrid. The evolution phases bases on general research publi-cations and visions of Smart Grids. Management architectures for the networks are pre-sented. Also requirements for communication are evaluated by studying the number of nodes, capacity requirements for transferred data types and fault and event frequencies. In order to define a proposal for integrating LV distribution networks to DA, the man-agement architectures and the studied requirements are compared to produce functions for DA. As a result, the proposal is presented based on the studied architectures and re-quirements. In addition considerable issues are introduced relating to the functions in devices or sub-systems, which are needed for DA applications. This thesis indicates the need for further studies, such as: Which are the desired DA functions to be extended to LV distribution networks? Which device or system should offer the desired functions? How well the potential protocols using some media type serves the functions?fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format