SIMetrex

What is the error?

Is D1 shorted?

Do you have two voltage sources stacked on top of one another? The "V" is clear, but the digit after is distorted, looks like two numbers superimposed.

-Mark

Thanks a million  i fixed the issue and it's simulating but am getting a straight line during simulation and this error "Warning : Cannot evaluate trace expression ':'

There are warnings. See list file for details, Error : Cannot find vector of name ':' 

Take a careful look at your schematic:

* R1 is short circuited , both sides are tied to ground.

* When V1's voltage is positive, D1 is reverse-biased and will be fine. But what do you think will happen when V1 is negative?

* You're using a 1N4148, which is a fairly low-current diode (Consult the datasheet.) It MIGHT simulate okay, but it would not work in real life. You'd get a more accurate simulation result if you chose a diode that could handle the full current, at the peak voltage.

* Your plot looks like an AC frequency sweep - is this the intent? Your initial question said you needed to measure true power; a transient simulation is better suited for that measurement.

Is this SIMetrix provided by ADI, or is it from another vendor? I'm not familiar with it (only LTspice.)

There is a note here: https://www.analog.com/en/design-center/interactive-design-tools/adisimpe.html

"LTspice is the preferred SPICE simulator of Analog Devices. We have sunsetted ADIsimPE, effective September 26, 2019. Unlike ADIsimPE, LTspice does not support SIMPLIS models. If you need SIMPLIS simulation capability, we recommend purchasing SIMetrix/SIMPLIS from www.simplis.com."

So if you're just doing simple circuits, consider LTspice.

-Mark

Take a careful look at your schematic:

* R1 is short circuited , both sides are tied to ground.

* When V1's voltage is positive, D1 is reverse-biased and will be fine. But what do you think will happen when V1 is negative?

* You're using a 1N4148, which is a fairly low-current diode (Consult the datasheet.) It MIGHT simulate okay, but it would not work in real life. You'd get a more accurate simulation result if you chose a diode that could handle the full current, at the peak voltage.

* Your plot looks like an AC frequency sweep - is this the intent? Your initial question said you needed to measure true power; a transient simulation is better suited for that measurement.

Is this SIMetrix provided by ADI, or is it from another vendor? I'm not familiar with it (only LTspice.)

There is a note here: https://www.analog.com/en/design-center/interactive-design-tools/adisimpe.html

"LTspice is the preferred SPICE simulator of Analog Devices. We have sunsetted ADIsimPE, effective September 26, 2019. Unlike ADIsimPE, LTspice does not support SIMPLIS models. If you need SIMPLIS simulation capability, we recommend purchasing SIMetrix/SIMPLIS from www.simplis.com."

So if you're just doing simple circuits, consider LTspice.

-Mark