This paper reviews the past and present uses of relay models. It discusses the various types of models, what information is required to build such models and the model validation process. Examples of present and possible future use of software models are given.

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Software models for relays

Modeling relays for power system protection studies

This paper describes modeling and simulation software developed specifically for teaching protective relaying application and design concepts. The emphasis was on implementing user-friendly and open-system solutions that will allow an easy use and straight-forward future expansion. This is achieved by introducing new libraries of signal sources and relay elements developed for the Simulink environment of MATLAB. Combined with the Power Block Set (PBS) toolbox of MATLAB, the mentioned libraries allow for a variety of studies aimed at a better understanding of protective relay design approaches and related applications.

/pdf/user-friendly-open-system-software-for-teaching-protective-43rb2u97qy.pdf

User-friendly, open-system software for teaching protective relaying application and design concepts

The purpose of this discussion is to provide an educational tool for investigating relaying concepts by modeling digital relays using TACS functions within EMTP in a closed-loop manner. Various elements of digital protection systems are identified and organized to generate an systematic approach to modeling the actual hardware of relay systems. Discussion is limited to conventional relaying systems that monitor the vitality of the 60 fit voltages and/or currents. TACS functions for transport delay and pulse generators are used to model dynamics associated with analog to digital conversion and sampling systems. DSP algorithms convert a sequence of sampled data into a sequence of values for magnitude and phase components. A simple example of a time overcurrent relay is developed to demonstrate the techniques to implement relay control in EMTP with TACS and illustrates the kinds of phenomena that can be studied using these techniques.

Using TACS functions within EMTP to teach protective relaying fundamentals

As the smart grid concepts are emphasized lately the need to modernize the power engineering education is also well recognized. This paper presents a set of newly developed modeling, simulation and testing tools aimed at better understanding the design concept and related applications for protective relaying and substation automation solutions for the smart grid. Since the smart grid applications require integration of data from multiple IEDs, understanding properties of each IED type in detail, as well as their responses to the power system events is needed. In addition, understanding the communication requirements to perform data integration is also important. To illustrate how the mentioned smart grid issues may be taught, the following advanced teaching approaches are presented: 1) Use of modeling and simulation means to better understand interaction between the relays and power system; 2) Use of IED test facilities to better understand performance of physical devices used for protection, monitoring and control; 3) Utilization of communication network modeling tools to simulate the communication network within Substation Automation System (SAS). Examples showing the use of proposed techniques for teaching the fundamentals and applications are presented. The examples demonstrate the adequacy and efficiency of the proposed techniques.

/pdf/modeling-and-simulation-tools-for-teaching-protective-qt1vd4wdqx.pdf

Modeling and simulation tools for teaching protective relaying design and application for the smart grid

An interactive software is presented for evaluating algorithms for digital relay designs. The software includes signal processing and protection modules that are used in digital relays. The software also includes facilities for generating data for testing the performance of digital relay designs. The performance of the designs can also be studied by using data recorded at a power system bus or generated by another software. The results can be displayed in the form of graphs for visual inspection. The software is interactive and can be used with ease. >

M. Nagpal

Papers

Interactive software for evaluating and teaching digital relaying algorithms