power dissipation in subcircuits

Joined: 18 Aug 2009 Posts: 14

I have a circuit that contains a model for a diode in a subcircuit (lets call it D1). Because this diode contains a PWL parasitic capacitance, there is energy storage in the subcircuit (just like a real diode) so when I plot P(D1), I get both the dissipated and reacted energy. Is there a way to extract the power from just the resistive components of the subcircuit?

Donny Zimmanck
Hardware Engineer
Enphase Energy

Site Admin Joined: 15 Jan 2009 Posts: 25

If I understand it right, you have a subcircuit (say X1) which contains diode, capacitor, and probably something else?

First, be careful with plotting P(X1): it does not handle right power of V/I sources in the subcircuit. If there are just passive components, it's OK. Will be fixed soon.

Second, you can plot any V/I/P at any specific component inside the subcircuit. Add a trace of "Function" type, and the function should be:

P(X1.D1)

Here X1 is subcurcuit component name, and D1 is a name of a diod inside a subcircuit. If you have more resistive components in the subcircuit, you can use a formula to add power on any components you'd like:

P(X1.D1)+P(X1.R1)+P(X1.R2)....

Site Admin Joined: 15 Jan 2009 Posts: 25

nl5 wrote:

First, be careful with plotting P(X1): it does not handle right power of V/I sources in the subcircuit...

Fixed in 1.33. P trace can be used for all SubCir models.