591 research outputs found

    Cascading verification initiated by switching attacks through compromised digital relays

    Get PDF
    Attackers are able to enumerate all devices and computers within a compromised substation network. Digital relays deployed in the substation are the devices with IP addresses that can be discovered in the process of trial-and-error search. This paper is concerned with studies of cyberattacks manipulating digital relays to disruptively disconnect the associated breakers. The plausible enumeration of such disruptive attack for each relay in a substation is verified with the dynamic simulation studies with the special protection system for frequency, voltage, and rotor angle stability. A pertinent approach with smaller scale contingency analysis results is proposed to reduce the enormous computation burden. The devised enumeration reduction method is evaluated using IEEE test cases. The proposed method provides an extensive enumeration strategy that can be used by utility engineers to identify the pivotal relays in the system and can be further strengthened with security protection

    A methodology for performance and compatibility evaluation of an all-digital substation protection system

    Get PDF
    A power system protection system consists, at least, of an instrument trans- former, a protective device (relay), and a circuit breaker. Conventional instrument transformers bring currents and voltages from power network levels to much lower scaled-down replicas that serve as input signals to protective relays. The relay's function is to measure input signals (or a relationship among them in some cases) and compare them to defined operating characteristic thresholds (relay settings) to quickly decide whether to operate associated circuit breaker(s). Existing protection systems within a substation are based on a hardwired interface between instrument transformers and protective relays. Recent development of electronic instrument transformers and the spread of digital relays allow the development of an all-digital protection system, in which the traditional analog interface has been replaced with a digital signal connected to digital relays through a digital communication link (process bus). Due to their design, conventional instrument transformers introduce distortions to the current and voltage signal replicas. These distortions may cause protective relays to misoperate. On the other hand, non-conventional instrument transformers promise distortion-free replicas, which, in turn, should translate into better relay performance. Replacing hardwired signals with a communication bus also reduces the significant cost associated with copper wiring. An all-digital system should provide compatibility and interoperability so that different electronic instrument transformers can be connected to different digital relays (under a multi-vendor connection) Since the novel all-digital system has never been implemented and/or tested in practice so far, its superior performance needs to be evaluated. This thesis proposes a methodology for performance and compatibility evaluation of an all-digital protection system through application testing. The approach defines the performance indices and compatibility indices as well as the evaluation methodology

    Power simulator upgrade for smart grid algorithm development and testing

    Get PDF
    This thesis describes the conversion of WVU\u27s analog power simulator into a micro-grid of the future test bed by installing digital relays and intelligent electronic switches. The simulator is a hardware representation of the grid which contains traditional hardware, both digital and analog as well as the recent addition of highly connected, via Ethernet and potentially wireless communication, smart switching and monitoring devices. These new devices were chosen specifically for their cyber security capability to explore that facet of smart grid development. It is important to note that this simulator is a hardware implementation and as such is capable of testing smart grid ideas in the most realistic setting available without affecting real customers. This simulator also has the potential to have renewable resources like wind and solar as well as fuel cell and battery storage distributed resources tied in to test smart grid adaptability to these next generation ideas.;New digital relays were installed. Micro controller units and energy meter integrated circuits were investigated based on the desire to provide many modes of communication and as much processing power as was available in a small package. Solid state switches were designed and implemented for speed, compactness and reduced power consumption

    PERAN RELE GE-SR489 SEBAGAI PENGAMAN ARUS BEBAN LEBIH DI GENERATOR PUSRI AREA IV PT. PUPUK SRIWIJAYA

    Get PDF
    Generator is an electric machine that converts mechanical energy into electricity. In Generator Pusri IV is using digital relays GE-SR489, relays GE-SR489 is a relays with 489 EnerVista Setup software for setting relays and set points for inputting setting data. From the recommendation setting trip time value is a 2,5s and from the calculating setting the value is 2,527. There is a difference until 0,027s that because for setting relays GE-SR489 even though this relays is digital relays and using set points for inputting setting data. There is still not really have a real value same as the calculating setting, so we take the closest value from 2,527 is a 2,5s for trip time

    Novel Pilot Directional Protection for the FREEDM Smart Grid System

    Get PDF
    abstract: The presence of distributed generation in high renewable energy penetration system increases the complexity for fault detection as the power flow is bidirectional. The conventional protection scheme is not sufficient for the bidirectional power flow system, hence a fast and accurate protection scheme needs to be developed. This thesis mainly deals with the design and validation of the protection system based on the Future Renewable Electric Energy Delivery and Management (FREEDM) system, which is a bidirectional power flow loop system. The Large-Scale System Simulation (LSSS) is a system level PSCAD model which is used to validate component models for different time-scale platforms to provide a virtual testing platform for the Future Renewable Electric Energy Delivery and Management (FREEDM) system. It is also used to validate the cases of power system protection, renewable energy integration and storage, and load profiles. The protection of the FREEDM system against any abnormal condition is one of the important tasks. Therefore, the pilot directional protection scheme based on wireless communication is used in this thesis. The use of wireless communication is extended to protect the large scale meshed distributed generation from any fault. The complete protection system consists of the main protection and the back-up protection which are both presented in the thesis. The validation of the protection system is performed on a radial system test bed using commercial relays at the ASU power laboratory, and on the RTDS platform (Real Time Digital Power System) in CAPS (Center for Advanced Power System) Florida. Considering that the commercial relays have limitations of high cost and communicating with fault isolation devices, a hardware prototype using the interface between the ADC (analog to digital converter) and MATLAB software is developed, which takes advantage of economic efficiency and communication compatibility. Part of this research work has been written into a conference paper which was presented by IEEE Green Tech Meeting, 2017.Dissertation/ThesisMasters Thesis Electrical Engineering 201
    corecore