113
Magtrol Model DSP7000 Dynamometer Controller
Chapter 10 – Theory
MAINTENACNCE
The speed correction factor is calculated on each entry into the PID loop equations.
Speed Correction Factor = - 0.0001 * x * 2 + 0.0203 * x + 0.005 limited to 0.051 to 1
where x = RPM / NOMINAL SPEED * 100
NOMINAL SPEED is set by the user and obtained from the data sheets for the dynamometer or brake.
10.1.3 equaTionS
Where Skp, Ski and Skd are system coefficients…
Yd(t) = (e(t) - e(t-3) + 3 * (e(t-1) - e(t-2))) * (10/Skd) * D%
Yp(t) = (e(t) + Yd(t)) * (10/Skp) * P%
Yi(t) = Yi(t-1) + (e(t) + Yd(t)) * (10/Ski) * I%
Yt(t) = Yp(t) + Yi(t)
Ys(t) = Scale * Yt(t)
10.2 ADDITIONAL SCALE FACTOR
The Additional Scale Factor is a multiplier of the P, I or D term. Due to the fact there are so many
different dynamometer types and motor combinations, this multiplier is needed to extend the range
of the PID. The letters represent the following:
A = 0.001 F = 0.5
B = 0.005 G = 1
C = 0.01 H = 5
D = 0.05 I = 10
E = 0.1
In using the multiplier, the user can input PID numbers from 0.001 (.001 x 1%) to 990 (10.0 x 99%)
with good resolution.
10.2.1 How To SeT aDDiTional SCale faCTor
Before following the setup instructions, the values that must be set will need to determined. This
will depend on which testing instrument has been chosen for the configuration. For appropriate
settings, refer to the guide provided in Appendix D: Additional Scale Factor Table. Once the proper
settings have been determined, proceed with the following instructions for setup.
10.2.1.1 Setting Additional Scale Factor for P (Proportional Gain)
1. Press SHIFT then the P button. Use the dial to change value (A, B, C, D, E, F, G, H and I).
2. Once the letter is chosen, press SHIFT to return to the main menu.
10.2.1.2 Setting Additional Scale Factor for I (Integral)
1. Press SHIFT then the I button. Use the dial to change value (A, B, C, D, E, F, G, H and I).
2. Once the letter is chosen, press SHIFT to return to the main menu.
10.2.1.3 Setting Additional Scale Factor for D (Derivative)
1. Press SHIFT then the D button. Use the dial to change value (A, B, C, D, E, F, G, H and
I).
2. Once the letter is chosen, press SHIFT to return to the main menu.
To Next Page
Loading...
Need help?
General