Micromod Micro-DCI: 53SL5100A Single Loop Controller Manual de usuario descargar pdf (Pagina 117)

Single Loop Process Controller Instruction Manual

Easy-Tune 109

11.5 Modifications to Tuning Criteria

During EASY-TUNE sequence execution, each of the three algorithm variables: Time Constant (TP ),

Process Gain (K

P), and Dead-Time (WP), are altered by 10% in the conservative direction, (instrument

operating characteristics would be slower response, but less chance of oscillation and instability) before

the tuning parameters are computed using the ITAE equations listed in Table 11-4. (Figure 11-2 illustrates

the equation variables with respect to the response curve.)

The three variables T

P, KP, and WP can be increased numerically to compute tuning parameters that are

more conservative, or decreased for less conservative tuning parameter calculations (instrument operating

characteristics would be faster response and greater chance of instability or oscillation). Parameters used

to alter the variables are the EASY-TUNE Modifiers, datapoints C382 (T

P Modifier), C383 (DP Modifier), and

C384 (W

P Modifier). It is recommended that the values entered in C382, C383, and C384 be between -0.5

and 0.5. The effect on the equation variables is as follows:

P modified = TP (1 - C382)

P modified = KP (1+ C383)

P modified = WP (1+ C384)

Table 11-4. EASY-TUNE Equations

Mode PB in % TR (Minutes) TR* (Minutes)

204KP(WP/TP)

1.084

116.4KP(WP/TP)

0.977

(TP/40.44)(WP/TP)

0.68

PID

73.69KP(WP/TP)

0.947

(TP/51.02)(WP/TP)

0.738

(TP/157.5)(WP/TP)

0.995

PD**

54.02KP(WP/TP)

0.947

0(TP/157.5)(WP/TP)

0.995

i**

0 TP[(KP/25)(WP/TP)

0.15

Note: Process characteristics TP, KP, and WP are used to compute the ideal tuning parameters according to the

Minimum Integral of Absolute Error Multiplied by Time Criterion (ITAE) for P, PI, and PID modes.

*If computed to be < B003/50, then T

D = 0.

**Empirical estimates, not based on ITAE method.

✎ Note The approximation of a process step response curve by a first order

time lag plus dead-time model is done by equating their values at

0.2835 and 0.6321 fraction of the total excursion.

1 2 ... 112 113 114 115 116 117 118 119 120 121 122 ... 151 152

Comentarios a estos manuales

Sin comentarios

Micromod Micro-DCI: 53SL5100A Single Loop Controller Manual de usuario Pagina 117

Comentarios a estos manuales

Relacionado con productos y manuales para Equipo Micromod Micro-DCI: 53SL5100A Single Loop Controller