System Constraints

The technical limitations that have not to be violated under 

any condition The violation of these constraints affects the 

power quality and the general operation of the power system

and causes stability problems The constraints can be divided

into two groups: equality constraints and inequality

constraints. Inequality constraints can have a hard nature,

where the variables are definite and specific like the

tap-changing transformer, or a soft nature, where the

variables are smoothly varied within a specific range like the

nodal voltages System

Constraints

1/ Equality constraints Inequality constraints

 2/ Inequality constraints

hard nature soft nature

The variables are The variables are definite and specific hl i d i hi like the tap-changing

transformer

soft nature

smoothly varied within a specific range like the nodal voltages