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Testing Tactics:

Surge Test For Electric Motors: Modern Variables for the Diagnostic of the Winding Insulation Condition

1 p.m. CT Thursday, September 22

Attendees of this webinar are eligible to receive 

 either 1 PDH or 0.1 CEU

The Surge test of electric motors has been an industry practice for more than 90 years, and can detect turn-to-turn, coil-to-coil, group-to-group, and phase-to-phase winding flaws that can not be detected by insulation resistance, dielectric absorption, or the hipot test. Through the years, we had several changes for the manufacturing of surge testers, and also changes in the way those testers can identify weak insulation in windings. Modern surge testers must obtain accurate calculations to predict or identify winding problems during the test.

 

This webinar will cover a brief history of the surge test, the old way to diagnose weak insulation, changes of the diagnostics through the years, evolution of standards, and the modern variables used during the surge test

Testing Tactics:

Systematic Approach to Testing Power Swing Blocking and Out-Of-Step Tripping Elements

10 a.m. CT Friday, September 23

Attendees of this webinar are eligible to receive 

1 NETA CTD and either 1 PDH or 0.1 CEU

Heavily loaded Power Systems operating near the stability limit are prone to the occurrence of power flow oscillations that happen because of the presence of a fault, loss of generation capacity, or other type of disturbance such as the loss or insertion of loads, in the system. Large Power Swings can cause unwanted relay operations which may aggravate the original power system disturbance resulting in cascading blackouts across the power system.


Modern protection systems can differentiate between stable and unstable Power Swings and operate properly for them using Power Swing Blocking and Out-Of-Step tripping elements. Properly testing these elements, requires understanding the difference between a stable and an unstable power swing, what is the principle of operation of such elements and how to generate the proper power system signals to simulate such conditions.

In this webinar we show the theory behind stable and unstable Power Swings as well as their effects in the operation of the power system. We show how relays can detect Power Swing conditions, and differentiate between a fault and a Power Swing to avoid unnecessary trips. We also discuss several methods used for Power Swing Blocking. We then show different ways to simulate Power Swings, and how to verify the proper operation of the Power Swing Blocking elements in the relay. We also show different ways to simulate unstable Power Swings and how to use the results of such simulations to properly test the operation of the Out-Of-Step protection in the protection system.

Testing Tactics:

Partial Discharge Fault Location on Power Transformers

10 a.m. CT Friday, October 21

Attendees of this webinar are eligible to receive 

1 NETA CTD and either 1 PDH or 0.1 CEU

Partial discharge (PD) is one of the first signs of a deteriorating insulation system and can lead to costly repairs or even failure of medium and high voltage (HV) equipment. Therefore, partial discharge measurements are vital concerning the quality assessment of high voltage products such as power/distribution transformers, cables, bushings, gas-insulated switchgears, and many others.

 

Among high voltage equipment, large power transformers have an insulation system with relatively high complexity. Compared to other HV assets the inner components of a transformer are not accessible. For this reason, testing is limited to the terminals and tank wall. Concerning detection of the PD activity during Factory Acceptance Test (FAT) or when the transformer is in service, the data regarding the fault location is very helpful for maintenance. This webinar explains general root causes of PD in power transformers and methods to locate the PD.