Siemens Module B3 manual With, Integral Action Controllers I- Controller

Automation and Drives - SCE

2.7.3.2 Integral Action Controllers (I- Controller)

Integrating controllers are used to completely correct system deviations at every operating point. As long as the system deviation is not equal to zero, the amount of the controller output changes. Only when the reference variable and the controlled variable are equal -at the latest however, when the controller output reaches its system-dependent limit (Umax, Pmax etc.)- is the controller in a steady state.

The mathematical formula for this integral action is:

The controller output is proportional to the time integral of the system deviation:

with

How fast the controller output rises (or falls), depends on the system deviation and the integration time.

Block Diagram

	Preface	Fundamentals	Discontinuous Action Controller Controller Block (S)FB41	Setting the System Appendix
	T I A Training Document		Page 24 of 64	Module
				B3
Issued: 02/2008				Control Engineering with STEP 7