Delta Electronics VFD-M manual PID Feedback Terminal Selection, Integral Time

Pr. 117

Chapter 4 Parameters

Targeted +						+	Limit of PID	One Time	Frequency
		P	I	Upper Bound +			Output
value				of Integral				Delay	Command
	-	Pr.117	Pr.118	Value		+	Frequency	Pr.121
					Pr.120		Pr.122
			D
			Pr.119
						Definition of		Selection of
			LPF			Detection Value		Detection value
					AVI(Pr.128~Pr.130)			Pr.116
			Pr.135		ACI(Pr.131~Pr.133)

Pr. 116 PID Feedback Terminal Selection

Factory Setting: 00

Settings 00 Input positive PID feedback, PV from AVI (0 to 10V)

01Input negative PID feedback, PV from AVI (0 to 10V)

02Input positive PID feedback, PV from ACI (4 to 20mA)

03Input negative PID feedback, PV from ACI (4 to 20mA)

Select an input terminal to be the PID feedback. Please verify the PID feedback position is different from the Frequency Set Point position.

Negative feedback = positive targeted value – detective value. Positive feedback = negative targeted value + detective value.

Proportional Gain (P)

Settings 0.0 to 10.0Factory Setting: 1.0

This parameter determines the feedback loop Gain. If the gain is large, the response will be strong and immediate (If the gain is too large, vibration may occur). If the gain is small, the response will be weak and slow.

When I=0.0 and D=0.0, it is only used for proportional control.

Pr. 118 Integral Time (I)

Unit: 0.01sec

Factory Setting: 1.00

Settings 0.01 to 100.00 sec 0.00 disable

This parameter determines the speed of response for the PID feedback loop. If the integral time is long, the response will be slow. If the integral time is short, the response will be quick. Be careful not to set (I) too small, since a rapid response may cause oscillation in the PID loop.

Revision May 2008, ME14, SW V3.04 4-77