Toshiba VF-AS1 Setting the PID control, Adjust PID control gain, Fast response, Slow response

E6581301

3) Setting the PID control

In case of controlling the airflow, water flow and pressure, please set the parameter ￿￿￿￿￿to”￿￿”(Process type PID control operation)

(1)Please set the parameter ￿￿￿(Acceleration time),!￿￿(deceleration time) to the suitable time for the system. (2)Please set the following parameters to place limits to the setting value and the control value.

Placing a limit to the process value : The parameter ￿￿￿￿(Process upper limit), ￿￿￿￿ (Process lower limit)

Placing a limit to the PID deviation : The parameter ￿￿￿￿(PID deviation upper limit ), ￿￿￿￿ (PID deviation lower limit )

Placing a limit to the PID output : The parameter ￿￿￿￿(PID output upper limit ), ￿￿￿￿ (PID output lower limit )

Placing a limit to the output frequency : The parameter ￿￿(Upper limit frequency ), ￿￿ (Lower limit frequency )

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4) Adjust PID control gain

Adjust PID control gains according to the process value, the feedback input signal and the item to be controlled. Here are the parameters used to adjust PID control gains.

Title	Function	Adjustment range	Default setting
￿￿￿￿￿	Proportional (P) gain	￿￿￿￿~￿￿￿￿￿￿	￿￿￿￿￿
￿￿￿￿￿	Integral (I) gain	￿￿￿￿~￿￿￿￿￿￿	￿￿￿￿￿
￿￿￿￿￿	Differential (D) gain	￿￿￿￿~￿￿￿￿￿	￿￿￿￿￿

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￿￿￿￿￿Proportional (P) gain

The proportional (P) gain set with f362 is the proportional (P) gain obtained by PID control.

A proportional (P) gain, a factor by which the deviation (difference between the process value and the feedback value) is multiplied, is used to perform control in such a way as to make a correction in proportion to the deviation.

6 Although setting this gain high is effective in increasing the response speed, setting it excessively high may cause an unstable operation, such as vibration.

	Feedback value
	High proportional gain ￿￿￿￿		Process value
	Fast response	Low proportional gain ￿￿￿￿
		Slow response
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				Time
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￿￿￿￿Integral (I) gain

The integral (I) gain set with f363 is the integral (I) gain obtained by PID control.

The integral gain reduces the deviation remaining after proportional control to zero (offsetting of residual deviation). Although setting this gain high is effective in reducing the residual deviation, setting it excessively high may cause an unstable operation, such as vibration.

Feedback value

Low integral gain ￿￿￿￿

Process value

Residual deviation

High integral gain ￿￿￿￿

Time

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