WOLFRAM SYSTEMMODELER

LimitedPI

Limited PI-controller with anti-windup and feed-forward

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Electrical.Machines.Examples.ControlledDCDrives.Utilities.LimitedPI"]
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Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Proportional - Integral - controller with optional feed-forward and limitation at the output.

The integral part can be switched off to obtain a limited P-controller.

The feed-forward gain can either be constant or given by the optional input kFF.

When the output is limited, the controller cannot bring the control error to zero and the integrator will not stop integrating. To avoid this WindUp - effect, an Anti-WindUp loop is implemented: The difference between unlimited and limited output is fed back to the integrator's input.

Parameters (13)

k

Value: 1

Type: Real

Description: Gain

useI

Value: true

Type: Boolean

Description: PI else P

Ti

Value: 1

Type: Time (s)

Description: Integral time constant (T>0 required)

useFF

Value: false

Type: Boolean

Description: Use feed-forward?

useConstantKFF

Value: true

Type: Boolean

Description: Use constant feed-forward factor?

KFF

Value: 1

Type: Real

Description: Feed-forward gain

constantLimits

Value: true

Type: Boolean

Description: Use constant limits?

symmetricLimits

Value: true

Type: Boolean

Description: Use symmetric limits?

yMax

Value: inf

Type: Real

Description: Upper limit of output

yMin

Value: -yMax

Type: Real

Description: Lower limit of output

initType

Value: Modelica.Blocks.Types.Init.NoInit

Type: Init

Description: Type of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output)

x_start

Value: 0

Type: Real

Description: Initial or guess value of state

y_start

Value: 0

Type: Real

Description: Initial value of output

Outputs (1)

controlError

Default Value: u - u_m

Type: Real

Description: Control error (set point - measurement)

Connectors (7)

u

Type: RealInput

Description: Connector of Real input signal

y

Type: RealOutput

Description: Connector of Real output signal

u_m

Type: RealInput

Description: Connector of measured signal

feedForward

Type: RealInput

Description: Connector of feed-forward signal

kFF

Type: RealInput

Description: Connector of feed-forward factor

yMaxVar

Type: RealInput

Description: Connector of yMax input signal

yMinVar

Type: RealInput

Description: Connector of yMin input signal

Components (13)

feedback

Type: Feedback

addAntiWindup

Type: Add

integrator

Type: Integrator

add3

Type: Add3

variableLimiter

Type: VariableLimiter

addSat

Type: Feedback

product

Type: Product

zeroI

Type: Constant

zeroFF

Type: Constant

constantKFF

Type: Constant

yMaxConst

Type: Constant

yMinConst

Type: Constant

gain

Type: Gain

Used in Examples (2)

SpeedControlledDCPM

Modelica.Electrical.Machines.Examples.ControlledDCDrives

Speed controlled DC PM drive with H-bridge from battery

PositionControlledDCPM

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Position controlled DC PM drive with H-bridge from battery

Used in Components (1)

PartialControlledDCPM

Modelica.Electrical.Machines.Examples.ControlledDCDrives.Utilities

Partial controlled DC PM drive with H-bridge from battery