# 3rd harmonic component of flux and current in Star -Star connected 3phase transformer

I wanted to understand what will be 3rd harmonic component of flux and current in following connection .

Connection - Star- Star connection (with neutral on primary side only)

Further description-

Balanced 3 phase sinusoidal Supply(also in star) is connected to primary winding(in star) of transformer with neutral also included while secondary winding (connected in star ) of transformer is connected to 3phase balanced linear load without neutral.

First I thought that since primary side has neutral connected to supply and hence 3rd harmonic component of current can flow through it and hence flux will be almost sinusoidal .Now on secondary side since flux is sinusoidal in primary so it should be sinusoidal also in secondary but problem is -

Load is connected in star without neutral so there is no possibility of 3rd harmonic current in secondary side and hence flux should have 3rd harmonic component but it is opposite to what I have concluded earlier .

Where did I make mistake in my analysis? what should be 3rd harmonic component of current and flux on both sides?

any help would be much appreciated!