Error in calculating power losses from direct current of the secondary winding of the LLC converter

Hello svarog46,

Good morning and thank you for choosing Power Integrations.

Let me check this one with the relevant team internally. I will give an update as soon as I receive feedback from them.

Thank you and have a great day ahead.

Regards,

Tommy

Thank you. I'm waiting for your reply.

Hello svarog46,

Good morning.

The formula for the estimated power loss due to DC resistance (DCR_Ploss_Sec1) is as follows:

DCR_Ploss _Sec1 =  (IO1)^2 * DCR_100C_Sec1 * 2

where IO1  (row 14) is the maximum main output current and DCR_100C_Sec1 (row 133) is the estimated resistance per phase at 100 C.

DCR_Ploss _Sec1 = (3)^2 * 29.33 mΩ * 2 = 0.52794 W = 0.53 W

I hope that this clarifies your inquiry. Let me know if there's anything that I can help you with.

Regards,

Tommy

Hello Tommy

Thank you for your attention.

A pulsating current flowsthrough eachsecondary half-winding, which contains a constant and an alternating component

If for the alternating component the power is determined by

row 135 is multiplied by row 127 squared and multiplied by two- and the result is clear !

Then why is a different formula givenfordirectcurrent –where is the logic?

Hi svarog46,

Good day.

Just a quick note: the actual DC current that will flow continuously through each winding at full load is the maximum main output current listed in row 14, which is 3 A. Therefore, this is the parameter used to calculate the estimated power loss due to DC resistance (DCR_Ploss_Sec1).

I hope this clarifies the confusion. Thank you and have a great day ahead.

Regards,

Tommy

Hello Tommy

I do not understand this calculation, then why write in row 126 that the constant component of the secondary half-winding is 1.5 amperes
if it is not applied, but the load current is applied I looked at several articles there calculating the power as I wrote

Hello svarog46,

Good morning.

Let me check this one internally and will let you know as soon as there's an update.

Thank you for your understanding.

Regards,

Tommy