Hitachi X200 Series instruction manual PID Control

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PID Control

Configuring Drive Parameters

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 set point (SP). The frequency command serves as the SP. The PID loop algorithm will read the analog input for the process variable (you specify the current or voltage input) and calculate the output.

•A scaled factor in A075 lets you multiply the PV factor, converting it into engineering units for the process.

•Potential, integral, and derivative gains are all adjustable.

•See “PID Loop Operation” on page 4-56for more information.

		“A” Function		Run		Defaults
Func.	Name /		Description	Mode -FE -FU				Units
Code	SRW Display			Edit	(EU)		(USA)
A071	PID enable		Enables PID function,		00		00	−
			two option codes:
			00…PID Disable
			01…PID Enable
	PID Mode	OFF
A072	PID proportional gain		Proportional gain has a range of	9	1.0		1.0	−
			0.2 to 5.0
	PID P	0001.0
A073	PID integral time constant		Integral time constant has a	9	1.0		1.0	sec
			range of 0.0 to 150 seconds
	PID I	0001.0s
A074	PID derivative time constant		Derivative time constant has a	9	0.00		0.00	sec
			range of 0.0 to 100 seconds
	PID D	000.00s
A075	PV scale conversion		Process Variable (PV), scale		1.00		1.00	−
			factor (multiplier), range of 0.01
	PID Cnv	001.00%	to 99.99
A076	PV source setting		Selects source of Process Variable		00		00	−
			(PV), option codes:
			00…[OI] terminal (current in)
			01…[O] terminal (voltage in)
			02…ModBus network
	PID INP	OI	10…Calculate function output
A077	Reverse PID action		Two option codes:		00		00	−
			00…PID input = SP-PV
			01…PID input = -(SP-PV)
	PID MINUS	OFF
A078	PID output limit		Sets the limit of PID output as		0.0		0.0	%
			percent of full scale,
	PID Vari	0000.0%	range is 0.0 to 100.0%

NOTE: The setting A073 for the integrator is the integrator’s time constant Ti, not the gain. The integrator gain Ki = 1/Ti. When you set A073 = 0, the integrator is disabled.