Is Multiplying Phase Readings a Valid Method to Verify Transformer Load Balance?

Click For Summary
SUMMARY

The discussion centers on verifying transformer load balance through the analysis of low-voltage (LV) side ampere readings. The method proposed involves multiplying the readings from phases R, S, and T to confirm their accuracy and assess neutral current. However, it is established that neutral current consists of both unbalanced load and third harmonic current, necessitating the use of a spectrum analyzer to differentiate between these components. This approach ensures a more accurate evaluation of load distribution and neutral current measurement.

PREREQUISITES
  • Understanding of transformer load balance concepts
  • Knowledge of electrical phase relationships (120-degree phase difference)
  • Familiarity with neutral current characteristics
  • Experience with spectrum analyzers for electrical measurements
NEXT STEPS
  • Research methods for analyzing neutral current using a spectrum analyzer
  • Learn about the impact of third harmonic current on neutral measurements
  • Investigate techniques for load balancing in electrical systems
  • Explore the principles of power factor correction in electrical devices
USEFUL FOR

Electrical engineers, technicians working with transformers, and professionals involved in load balancing and electrical measurements will benefit from this discussion.

Muhammad Saber
Messages
1
Reaction score
0
I'm working in electrical company in a department in which I receive transformer LV side ampere readings and in most of these readings the neutral has amperege due to unbalanced loading, all I need a method in which I be certain that these readings are actual measured values specially neutral measuremen to make reldistributing the load to the phases, I thought that when I multiply the r,s,t readings the phase between r,s,t which is 120 diffrence it will make me be sure that these phases reading are correct and the neutral amperege. Is that right , if not what is the way to investigate these readings.
 
Engineering news on Phys.org
Muhammad Saber said:
I thought that when I multiply the r,s,t readings the phase between r,s,t which is 120 diffrence it will make me be sure that these phases reading are correct

i cannot make sense of that sentence.

What are you multiplying by what ? and why ?


Muhammad Saber said:
and the neutral amperege
Neutral current includes both unbalance AND third harmonic current.
Electronic devices made before power factor correction was mandated draw a lot of third harmonic current that shows up in the neutral. .
You'll need to look at your neutral current with a spectrum analyzer to know how much of it is at line frequency(unbalance) and how much is at 3X line frequency(electronic loads).
 
Last edited:
  • Like
Likes   Reactions: dlgoff

Similar threads

  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
7K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
20
Views
35K