[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

# SRM Inductance plot at constant current

- To: <femm@yahoogroups.com>
- Subject: SRM Inductance plot at constant current
- From: "Brad Frustaglio" <fuzz@wildrail.net>
- Date: Tue, 6 May 2003 08:26:10 -0500
- Importance: Normal
- In-reply-to: <86916FE08FDA1C4BA606D0331B6F4D46069CAF@stivesmail.linx.co.uk>

Hi All, I have been using FEMM for a few years now. Many thanks to Dave, excellent program. I have question on evaluating the A-J integral and then calculating the self inductance from the result. I am modeling a 4 phase SRM with 8 stator poles and 6 rotor poles. I am attempting to extract the torque profile and inductance profile with one phase excited at constant current as the rotor moves through one stroke. The torque magnitude and shape looks reasonable. However I am having trouble understanding how to calculate the inductance correctly. The profile shape looks as expected I am just concerned on the magnitude of inductance. My method is: Highlight the blocks with the current flowing ( In my case there are 2 current blocks per pole (one on each side of the stator pole) for a total of 4 current blocks per phase. Evaluate the A-J integral at each respective rotor position The self inductance as defined is int(A-J)dV /i^2) where i is the coil current I think I am running into trouble on the coil current term. What is the correct coil current to use to evaluate the inductance correctly? The value of one current block or the sum of all current blocks.Also this is actually amp-turns. Not the actual current flowing in the wire itself. Right? For instance: the current in one blockin the model is defined as 11.15 MA/m^2. The coil area is 2.6903 x 10^-5 m^2. So the magnitude of current in the coil block is 300 A-T. Is this the current I use for the evaluation of self inductance using the A-J integral? Regards, Brad Frustaglio

- Follow-Ups:
  - Re: [femm] SRM Inductance plot at constant current
    - From: David Meeker <dmeeker@ieee.org>

- References:
  - RE: [femm] Density plot colours and Lua
    - From: Mark Smith <mark.smith@linx.co.uk>

- Prev by Date: RE: [femm] Density plot colours and Lua
- Next by Date: Re: [femm] SRM Inductance plot at constant current
- Previous by thread: RE: [femm] Density plot colours and Lua
- Next by thread: Re: [femm] SRM Inductance plot at constant current
- Index(es):
  - Date
  - Thread