[Gnucap-devel] Re: PSS analysis

[henrik johansson]

Hi again,

The only general and practical solution to the problem I think is to
go from NA to MNA forumulation, at least for the inductors. I don't
think this would be so difficult.

The issues that comes to mind are: current state vector has to be
added to SIM, coil device has to be re-written, convergence criterions
have to be changed, current probes should use the current state.

What do you think Al?

Best regards,

Henrik

2009/6/1 henrik johansson <address@hidden>:
> Hi Al,
>
> I'm trying to find a solution to how to set the initial condition for
> inner transient analysis. Correct me if I'm wrong but isn't it
> impossible to calculate the state-transition function Phi(v0, 0, T)
> and the jacobian of it Jphi with NA since the full-state of the
> circuit is not captured by the voltage vector. Using MNA the vector of
> node voltages and currents through inductors represents the state of
> the circuit.
>
> It would be possible to probe the current of all inductors and then
> calculate the MNA matrix and LU-factor it for each timestep and then
> use that to calculate the state-transition Jacobian. But it would be a
> pity to not use the NA Jacobian. But I don't know how to handle this
> for spice-devices.
>
> Any ideas?
>
> Best regards,
>
> Henrik
>