Hi, anyone knows why my switching losses of my boost converter is too high?
i have a boost converter that its output voltage should be regulated at 388VDC.
However, my circuit works with very low efficiency, when my load is 70W, and i put in input voltage of 80W, there is no voltage regulation. In fact, the output votlage dropped to 288VDC.

input voltage was 80W and output voltage was 40W, which means the remaining 40W was switching losses. I am wondering why? The voltage feedback loop is working fine.


The boost topology has this formula, Vout/Vin=1/(1-D)
However when the Duty cycle is too high, out Vout will saturate at a point. so when the output voltage saturates, will it cause high switching losses?

my circuit i am working on is actually a power factor correction rectifier circuit connected to a converter.

I obtained unity power factor but not voltage regulation. So i think the problem in my circuit is on the dc-dc converter.

As Duty cycle of the mosfet increases, the switching losses will be higher?

It would help if you added the component values that you are using. What are you supplying Vcc from?

Also voltage is measured in Volts (V) and power is measured in Watts, W so

Originally Posted by yuchween

input voltage was 80W and output voltage was 40W, which means the remaining 40W was switching losses.

doesn't really make any sense.

You should tell us what the input voltage and current are, and what the output voltage and current are.

Sorry was my mistake. I meant was input power and output power.
In Watts.

I dont think those values do much in my question. I just like to know when the duty cycle of the converter saturates, means if the duty cycle increases, there will no longer be any increase in output voltage.
Boost converter voltages are governed by this equation:
Vout/Vin=1/(1-D)

When D further increase beyond 0.8, the boost level will saturate. During that saturation, will the switching losses increase drastically?