Biblioteca Técnica

PD Scan - Reporting Software and Firmware

The Power Grid Corporation of India Limited (PGCIL) is an Indian state-owned company headquartered in Gurugram (North India) engaged mainly in Trans-mission  of  Power  and  transmits  about  50%  of  the  total  power  generated  in  India  on  its  transmission  network.  The  company  owns  and  operates  about  1,61,790  circuit  kms  of  transmission  lines  at  800/765 kV,  400 kV,  220 kV  &  132 kV EHVAC and +500 kV HVDC levels and 248 sub-stations. Also, it has the transformation capacity of about 396 825 MVA as of 30th November 2019.

Transformer equipment manufacturers (OEMs) have a critical need to measure true ratio, as they must confirm proper manufacture of their transformers during construction and final assembly. Improper construction has consequences of higher cost, late delivery, and poor quality. The ability of a ratio instrument to be used for all steps involved makes it a practical valueto OEMs because only one instrument is purchased and used throughout each stage. Only the most reliable and accurate instruments make it to the factory floor. Winding stack under constructionre used: Art Mandigo Winding Service.

This application note is more than a description of how to use SVERKER 900 for testing frequency relays. It also wantsto spread the knowledge about IEC standardization in relay protection. Many engineers often associate theIEC series of protection standards IEC 60255-1xx1to relay type testing, and believe that they do not need to have competence about this series of standards. This is a misunderstanding: many of the concepts, definitions and test procedures described in thestandards are there to be used in relay technique, no matter if the role is relay manufacturer, user, or commissioning / maintenance testing engineer ([2], [3]).

When measuring very low resistance the four-wire test method has for many years been the standard method. The main advantage being that it simply and easily removes the resistance of the test leads from the measurement. However, what happens when those test leads need to be verylong?

Introducing the first low resistance ohmmeter to feature a difference meter, a device that turns changes in resistance into a moving pointer and percentage change. When testing multiple similar connections, it makes it easy to spot those small increases in resistance that eventually turn into major faults.

Safety warnings for DLRO2

Software download files for PowerDB

Software for the SmartFuse 250

Megger’s article “Transformer Winding Resistance Measurement: Field Challenges” was presented at the 2020 NETA PowerTest Conference in Chicago, Il. This article takes an in-depth look at the lesser known facts associated with the DC winding resistance (WR) measurements, diving deeper into topics such as selection of the correct test current, and the importance of compliance voltage during the test. Phenomena as core saturation, current stabilization, the influence of winding inductance on readings, and the effect of temperature, are also explained.