Re: gEDA-user: Non-linear spice models for power sources operating near stall
Turned out that the mechanical coupling coefffient is so low that a stall cannot occur. So Matthew W.'s #1 approach will work for me. Thanks everyone for the help! Mike On Wed, 2010-06-02 at 20:13 +0200, Armin Faltl wrote: > > Mike Crowe wrote: > >>3. More complicated models would vary the inductance depending on > >>rotation speed, electrical frequency and possibly angular position of > >>the rotor... but hopefully you don't have to go that far. > >>All in all... I think Spice will be a pretty awkward tool to do any > >>more than (1.). I'd look at something like University of South > >>Carolina's VTB (Virtual Test Bed). It's free, but closed source. > >> > > Unfortunately, I believe that the model will be more like #3. The power > > source is a periodic hydraulic one. My ultimate task is to deliver peak > > power from the mechanical system regardless of the available input power > > (wave action). In addition to modeling the motor, I will need to model > > the mechanical components.I looked briefly at the SC site, but it > > requires a plug-in that I don't have. > > > How about setting up the differential equations of your dynamic model. > If you can formulate > them as a system of ordinary explicit de's and as initial value problem, > you can use a > Runge-Kutta method, that should be readily available as C-source (or at > least FORTRAN). > > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Non-linear spice models for power sources operating near stall
Mike Crowe wrote: 3. More complicated models would vary the inductance depending on rotation speed, electrical frequency and possibly angular position of the rotor... but hopefully you don't have to go that far. All in all... I think Spice will be a pretty awkward tool to do any more than (1.). I'd look at something like University of South Carolina's VTB (Virtual Test Bed). It's free, but closed source. Unfortunately, I believe that the model will be more like #3. The power source is a periodic hydraulic one. My ultimate task is to deliver peak power from the mechanical system regardless of the available input power (wave action). In addition to modeling the motor, I will need to model the mechanical components.I looked briefly at the SC site, but it requires a plug-in that I don't have. How about setting up the differential equations of your dynamic model. If you can formulate them as a system of ordinary explicit de's and as initial value problem, you can use a Runge-Kutta method, that should be readily available as C-source (or at least FORTRAN). ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Non-linear spice models for power sources operating near stall
On Wed, 2010-06-02 at 09:17 -0700, Matthew Wilkins wrote: > I guess it depends how sophisticated you want your model to be. >1. A simple motor/generator model is a resistor, inductor and voltage >source in series. The voltage source is proportional to speed. Torque >is proportional to current through the winding. You can measure the >values directly from the motor; keep the rotor stationary for the >resistance and inductance measurements. This is sufficient for a lot >of motor modelling work. >2. If you're truly stalling the generator, you might want to map out >the inductance measurements at different rotor positions. Also, you >might be able to model cogging torque by putting a sinusoidal current >source in parallel with the winding, with phase controlled by a >multiple of rotor position. >3. More complicated models would vary the inductance depending on >rotation speed, electrical frequency and possibly angular position of >the rotor... but hopefully you don't have to go that far. >All in all... I think Spice will be a pretty awkward tool to do any >more than (1.). I'd look at something like University of South >Carolina's VTB (Virtual Test Bed). It's free, but closed source. Unfortunately, I believe that the model will be more like #3. The power source is a periodic hydraulic one. My ultimate task is to deliver peak power from the mechanical system regardless of the available input power (wave action). In addition to modeling the motor, I will need to model the mechanical components.I looked briefly at the SC site, but it requires a plug-in that I don't have. > __ > >From: Mike Crowe > To: gEDA user mailing list >Sent: Wed, June 2, 2010 7:28:43 AM >Subject: gEDA-user: Non-linear spice models for power sources operating >near stall >Hello >Somewhat off topic, but >I am working on an energy harvesting device which uses a small >generator >(<100W). I am looking for a spice model that I can use as a template >to >create a model for the motor dynamics near stall. Can anyone point me >to a good starting point? >Thanks >Mike >___ >geda-user mailing list >[1]geda-u...@moria.seul.org >[2]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > References > >1. mailto:geda-user@moria.seul.org >2. http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Non-linear spice models for power sources operating near stall
I guess it depends how sophisticated you want your model to be. 1. A simple motor/generator model is a resistor, inductor and voltage source in series. The voltage source is proportional to speed. Torque is proportional to current through the winding. You can measure the values directly from the motor; keep the rotor stationary for the resistance and inductance measurements. This is sufficient for a lot of motor modelling work. 2. If you're truly stalling the generator, you might want to map out the inductance measurements at different rotor positions. Also, you might be able to model cogging torque by putting a sinusoidal current source in parallel with the winding, with phase controlled by a multiple of rotor position. 3. More complicated models would vary the inductance depending on rotation speed, electrical frequency and possibly angular position of the rotor... but hopefully you don't have to go that far. All in all... I think Spice will be a pretty awkward tool to do any more than (1.). I'd look at something like University of South Carolina's VTB (Virtual Test Bed). It's free, but closed source. __ From: Mike Crowe To: gEDA user mailing list Sent: Wed, June 2, 2010 7:28:43 AM Subject: gEDA-user: Non-linear spice models for power sources operating near stall Hello Somewhat off topic, but I am working on an energy harvesting device which uses a small generator (<100W). I am looking for a spice model that I can use as a template to create a model for the motor dynamics near stall. Can anyone point me to a good starting point? Thanks Mike ___ geda-user mailing list [1]geda-u...@moria.seul.org [2]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user References 1. mailto:geda-user@moria.seul.org 2. http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: Non-linear spice models for power sources operating near stall
Hello Somewhat off topic, but I am working on an energy harvesting device which uses a small generator (<100W). I am looking for a spice model that I can use as a template to create a model for the motor dynamics near stall. Can anyone point me to a good starting point? Thanks Mike ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
