Relay Training Center Software 

is a self-paced tutorial. With every topic presented there is a page for trying your hand at the practical calculations.

This software became the basis for both our seminar and the Relays 101 Part 1.pdf booklet. 

From this package you will learn how to calculate:

Symmetrical Components

Phase-to-Phase values

Apparent Fault Impedance

Primary-to-Secondary Impedance Conversions

(and much more) 

The Relay Training Center "Excel-lent" Training Modules

are built as spreadsheet workbooks in MS Office Excel (97 or later). These modules use some spreadsheet functions but mostly the built in VBA capability of Excel. You must have Excel 97 or later and you must allow macros for these modules to run.

Every training module has a cover page, at least one lesson page and a simulation page. Read the lesson and learn. Click on the simulator page and play with the graphics and calculations built into the various Visual Basic tools that are used in the simulator.

87B 

Here we see the 87B Training Module. Since this module (and all modules) are NOT password protected then you can add to the lesson. These lessons are presented skeleton-style; bare-bones so that you can add the narrative text that already exists in your own training program.

Or use them as is for a pre-built training program. This 87B training module has a short topic and a simulator that shows circuit breakers, a bypass disconnect, CT's, a trip circuit and the ability to adjust some of the circuit parameters so that you can see when and why the 87B might trip.

If your CT Ratios do not match then you will see the relay current go above zero. Close the bypass disconnect and watch the CB's open!

Click on the images to see full-size images for better viewing detail. 

87T 

Relay Training Center has 4 87T training modules built from a common framework. 87T1 shows how a transformer differential is supposed to work. But close a bypass disconnect and watch the CB's open!

87T2 adds to that the ability to mismatch the CT ratios, change DETC and LTC tap positions and give the transformer an external fault so that you can see your transformer differential operate! 

87T3 allows you to see how CT errors can affect your 87T protective relaying scheme. 

87T4 gives you the tap changer and CT errors, the CT ratio changes, the bypass disconnect, the through fault and a minimum pickup and slope setting for the relay.

The first two modules are good for all trainees; including future system operators, switchmen and relay technicians. The final two modules give details intended for protective relay technician trainees. 

CB Control Scheme 

This is a circuit breaker control scheme. Select Local and see the local permissive contacts close; select Supervisory and see the local permissive contacts open and the supervisory permissive contacts close. Turn the reclosing relay on and watch the 79CO permissive contacts close. Apply a bolted fault and close the CB with the Anti-Pump scheme operational. Try it again with the Anti-Pump disabled; the low-air lock-out will prevent this simulator from running forever. This training module is designed with system operators, switchmen, station operators, apparatus electricians and relay technicians in mind.

Intro to Relays - 27, 50, 67

and Step Distance Concepts

 These three modules are excellent for anyone involved with substations. The concepts that are presented are basic and required knowledge for all.

Protective relay technicians, of course, will build upon these concepts. System operators need these topics as a general foundation of how-things-work.

The module on 27 & 50 devices allows the user to set the relays' pick-up points. Adjust the circuit parameters and watch the relay contacts close that would ordinarily trip the circuit breaker. The power transformer ratios, PT Ratios and CT ratios are all variable; another teaching point for your future technicians and operators.

There is no hair-pulling in calibrating these relays but everything else is the same. Learn the concepts of calibrations from a simulator built on a spreadsheet framework. Trip the CB on your laptop instead of in real life!

The 67 Relay demonstrates graphically the difference between a 67 and a 50 device. Adjust relay pick-up points, CT Ratios and circuit parameters. Set load current or apply a fault. Change direction of current flow and predict which 67 relay will pick and watch the CB's trip!

Intro to Step-Distance does not teach distance relay calibration. Rather it introduces the concepts of "zones" in a package of protection on transmission lines. Zones are there for a reason. There are errors that must be accounted for with relay protection and there is a desire to trip only the faulted line section. This module provides an environment that demonstrates how zones work for step-distance protection. 

CT Polarity

CT's & PT's

Neutral Current

These three modules present topics that are needed without necessarily being unique to protective relay technicians.

A question posed to a system operator was: "Do you need to know about Zero-Sequence Quantities?" 

His response was: "Absolutely not!"

Next question: "Would you like to know about Neutral Current occurring during single-phase switching?"

Response: "Yes!"

These modules concentrate on Transformer Ratios, CT Polarity and Unbalanced Current.

These modules do not get hung up in the dialog about Symmetrical Components. They are straight forward topics for the Journey-Level Operators.

Any technician or operator that has ever had to decipher a Bus Differential Scheme needs to understand CT's and CT Polarity.

If you ever find yourself single-phase switching then you need to know the reason to why you must disable ground-tripping.