Siemens Module B3 manual Setting the PI-Controller according to Ziegler-Nichols

Page 55

Automation and Drives - SCE

5.2 Setting the PI-Controller according to Ziegler-Nichols

By experimenting with P-T1-TLsystems, Ziegler and Nichols have found the following optimum controller settings for fixed setpoint control:

KPR =00,9.

Tg

KSTu

TN =33,33. Tu

In general, we get disturbance characteristics with these setting values that are quite good. [7]

5.3 Setting the PID Controller according to Chien, Hrones and Reswick

For this method, the response to setpoint characteristics as well as disturbance characteristics was examined, in order to get the most favorable controller parameters. Different values resulted for both cases.

The following settings were the result:
• For disturbance characteristics:
aperiodischer Einschwing-			20% overshoot
Apriodical transient reaction			20% Überschwingen
vorgang mit kürzester Dauer			Minimum period of oscillation
with the shortest period			minimale Schwingungsdauer
0.	Tg			Tg

			KPR = 0,7.
KPR = ,6
	KSTu			KSTu

TN = 4 Tu

TN = 2.,3 Tu

	Preface Fundamentals	Discontinuous Action Controller Controller Block (S)FB41	Setting the System Appendix

	T I A Training Document	Page 55 of 64	Module
			B3
Issued: 02/2008			Control Engineering with STEP 7

Image 55

Contents Module B3 Automation and Drives SCE Table of Contents Automation and Drives SCE Prerequisites To 3 days Module C To 3 days Module DFrequency Converter at Simatic S7 Learning ObjectivePLC Hardware and software requiredTasks of Control Engineering Fundamentals of Control EngineeringControlled Variable Components of a Control LoopFeedback Variable r Controlling Element Disturbance Variable zSetpoint Value w Comparing ElementControlled System ActuatorDead Time Characteristics Step Function for Examining Controlled Systems ForAutomation and Drives SCE Time constant Proportional Controlled System with a Time DelayTu Delay time Tg Transition time Proportional Controlled System with Two Time DelaysControllability of P-Tn systems Proportional Controlled System with n Time Delays Controlled Systems without Inherent Regulation Types of Controllers Two Position Controllers Hysteresis Switch-On Value Manipulated Variable TimeThree Position Controllers Basic Types of Continuous Controllers Proportional Controllers P-Controller Automation and Drives SCE Integral Action Controllers I- Controller WithController Layout PI ControllersPID Controllers Derivative Action Controllers D-ControllerObjectives for Controller Adjustment 450.85 Digital Controllers DAC Preface Fundamentals YES StructogramExercise Assignment List Symbol Address CommentNetwork Possible Solution for the PLC ProgramD24/AIFillSetpNorm/Norm.value for level setpoint Network 10 Title Task Definition for PID Standard Controller Function Diagram of the control system with a PID controller Use FB 41 ContcDescription Exercise Example Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE SP INT PLC’ Automation and Drives SCE Automation and Drives SCE Automation and Drives SCE Tu-TgApproximation GeneralT g Approximation Setting the PI-Controller according to Ziegler-Nichols For setpoint characteristic MAN Solution of the PLC program Setpoint Setting the PI controller according to Ziegler-NicholsAppendix Diagram of the controller blockComrst Bool False Input Parameters Data Value Range Default Description TypeParameter Data Type Value Range Default Lmnhlm Real Lmnllm Output Parameters Parameter Data Value Range Default Description Type