How to Solve Transformer Flux, Reluctance, MMF, and Magnetic Circuits

[Zach Stone P.E.]

Magnetic circuits used to be one of my least favorite types of problems on the electrical power PE exam.It seemed overly complicated and resources that taught this type of problem were hard to find without diving too far into the subject of physics, which is beyond what the PE exam tests on.

The two videos below go over how to:

• Relate the magnetic circuit variables (f = ΦR) to electrical circuit variables that we are more familiar with (V = IR).
  
• Convert any magnetic circuit, even with an air gap, into an electrical equivalent circuit.
  
• How to write Kirchoff's Current Law (KCL) equations using magnetic circuit variables (f = ΦR).
  
• How to combine series and parallel reluctances (R) in a magnetic circuit to determine the total equivalent reluctance (Req)
  

To make sure you really understand transformer flux and magnetic circuit problems, we also included two practice problems worked out and solved on video for extra practice.
 


1. Transformer Magnetic Circuit, Flux, and Reluctance Practice Problem