LLC – Lead-lag compensator

Block SymbolLicensing group: STANDARD
PIC

Function Description
The LLC block is a discrete simulator of integral-derivative element

C(s) = atau s + 1 tau s + 1 ,

where tau is the denominator time constant and the time constant of numerator is an a-multiple of tau (atau). If ISSF = on, then the state of the filter is set to the steady value at the block initialization according to the input signal u.

This block is ideal for simulation of first order plus dead time systems (FOPDT). Just set the a parameter to zero.

The exact discretization at the sampling instants is used for discretization of the C(s) transfer function. The sampling period used for discretization is equivalent to the execution period of the LLC block.

Input

u

Analog input of the block

double

Output

y

Analog output of the block

double

Parameters

tau

Time constant  1.0

double

a

Numerator time constant coefficient

double

ISSF

Steady state at start-up

bool

off ..

Zero initial state

on ...

Initial steady state