Voltage Gain of Booster Converter at 1kHz and 5kHz

[ToonBlue]

Homework Statement

Does the voltage gain follows the a linear relationship when the switching frequency is 5 kHz? and does it still follow the linear relationship when it is 1k Hz?

Homework Equations

The Attempt at a Solution

I am doing an experiment on this and I have found out that through simulation result using a software.
When the Switching frequency is 5 kHz , it doesn't follows a linear relationship but it follow a linear relationship when it has been change to 1 kHz.

On the actual experiment itself , for both cases (switching frequency is 5kHz or 1kHz) , it doesn't follow a linear relationship.

so now I am confused. I have read on some website that for booster converter , voltage gain doesn't follow linear relationship.

 

[berkeman]

Homework Statement

Does the voltage gain follows the a linear relationship when the switching frequency is 5 kHz? and does it still follow the linear relationship when it is 1k Hz?

Homework Equations

The Attempt at a Solution

I am doing an experiment on this and I have found out that through simulation result using a software.
When the Switching frequency is 5 kHz , it doesn't follows a linear relationship but it follow a linear relationship when it has been change to 1 kHz.

On the actual experiment itself , for both cases (switching frequency is 5kHz or 1kHz) , it doesn't follow a linear relationship.

so now I am confused. I have read on some website that for booster converter , voltage gain doesn't follow linear relationship.

Can you post your simulation results and you SPICE decks?

 

[ToonBlue]

In general . does switching frequency affect the linear relationship of voltage gain with respect to the duty cycle?

 

[ToonBlue]

I would like to ask one more question. Does this consider to be a linear relationship ? It doesn't look very linear to me?

 

[berkeman]

Can you label the axes? Or say what they are?

Does your simulation use real voltages for the diode and transistor switch? What about reverse recovery time of the diode, and the frequency characteristics of the transistor?

 

[rude man]

If you write the equation for the current thru the inductor at the end of the "ON" cycle, and the equation at the end of the "OFF" cycle, and realizing that the currenmt at the end of the "OFF" cycle must equal the current at the beginning of the "ON" cycle, then you can easily show that the relationship is not linear in the duty cycle δ defined as δ = "ON" time / ("ON" time + "OFF" time).

This assumes that the output voltage is constant (large output capacitor, not too large a load). "ON" means the transistor is on. Also ideal transistor and diode characteristics.

You can also show that for small δ the relationship between the duty cycle and the output voltage is approximately linear.