# Modeling a Flyback Converter with a Lot of Parasitic Components

#### BlackMelon

Joined Mar 19, 2015
143
Dear All,

I would like to include all capacitances in the MOSFET, practical model of the transformer including cap from primary to secondary, cap between turns of the primary side, etc.. If I am going to solve the system's equation, what is the most popular way to do this?

Without knowing the value of parasitic components in advance, if I want to derive an output response equation, having parasitics as parameters, can numerical methods do this? If so, could you suggest books for this job? If not, any good books for solving high order differential equations?

BlackMelon

#### crutschow

Joined Mar 14, 2008
31,126
Do you need to solve this mathematically?
Much easier to simulate it with a Spice simulator such as the free LTspice.

#### ci139

Joined Jul 11, 2016
1,873
I/O ?power/?voltage/?current ← ranges the possible topologies , device parameters , literature

#### BlackMelon

Joined Mar 19, 2015
143
Do you need to solve this mathematically?
Much easier to simulate it with a Spice simulator such as the free LTspice.
Yes, that's what people do in both my ex-company and the current one. But I wonder if I can make a math model works too.

I/O ?power/?voltage/?current ← ranges the possible topologies , device parameters , literature
130W, nominal voltage and current: 24V, 5.417A. Quasi-resonant flyback converter (Power switches are a MOSFET on the primary side and a diode on the secondary side). I am going to design based on Infineon's paper.

#### ci139

Joined Jul 11, 2016
1,873
is the 130W output at ~120V/230V AC . . . "diode at output" so it's DC out
https://www.mouser.com/pdfdocs/2-9.pdf ← i must seek other data on QR feature

anyway 130W RMS may mean some 50A capable pulse TF (unless the QR somehow significantly reduces that . . .)

(((i hate that party)))