Hitachi L100 instruction manual PID Control

L100 Inverter

3–17

PID Control

When enabled, the built-in PID loop calculates an ideal inverter output value to cause a loop feedback process variable (PV) to move closer in value to the setpoint (SP). The current frequency command serves as the SP. The PID loop calculations will read the analog input for the process variable (you specify the current or voltage input) and calcu- late the output. A scale factor in A75 lets you multiply the PV by a factor, converting it into engineering units for the process. Proportional, integral, and derivative gains are all adjustable. See page 4–27 for more information on PID loop control.

	“A” Function		Run-	Defaults		DOP,DRW,DOP+
Func.	Name	Description	time	EU/	Units	Func.	Name
			Edit
Code				US		Code
A71	PID Function Enable	Enables PID function,	✘	00	—	F-43	PID SW
		two option codes:
		00... PID Disable
		01... PID Enable
A72	PID proportional gain	Proportional gain has a range	✘	1.0	—	F-43	PID P
		of 0.2 to 5.0
A73	PID integral time	Integral time constant has a	✘	1.0	sec.	F-43	PID I
	constant	range of 0.0 to 150 seconds
A74	PID derivative gain	Derivative gain has a range of	✘	0.0	sec.	F-43	PID D
		0.0 to 100 seconds
A75	PV scale conversion	Process Variable (PV) scale	✘	1.0	—	F-43	PID
		factor (multiplier), range of					CONV
		0.01 to 99.99
A76	PV source setting	Selects source of Process	✘	00	—	F-43	PID INPT
		Variable (PV), option codes:
		00... “OI” terminal (current in)
		01... “O” terminal (voltage in)

NOTE: The setting A73 for the integrator is the integrator’s time constant Ti, not the gain. The integrator gain Ki = 1/Ti. When you set A73 = 0, the integrator is disabled.

Drive Parameters Configuring