Module 6 : Preventive, Emergency and Restorative Control
Lecture 25 : Introduction
Objectives
In this lecture you will learn the following
Nature of Control Actions in a Power System
Brief recap on operating states and control actions
The role of the load dispatch center
Nature of Control Actions in a Power System
W hat we have learnt so far can be broadly classified as follows:
1. Frequency, voltage and power flow control
2. Real and Reactive power scheduling
Essentially, these are "routine" control actions of a manual controller (i.e., a system/plant
operator) or an automatic controller (like a generator terminal voltage regulator).
">These actions ensure a good quality supply (i.e., near-constant voltage and frequency) at a low cost.
">However, an important class of control actions are appropriate when a system is not in a "normal" state. To
understand this let us revisit a previous lecture on various operating states of a power system.
Operating states and nature of control actions (revisited)
The state (or condition) of a power system can be judged from the answers to the following questions:
Is the demanded load being met ?(i.e., is there a real and reactive power balance?)
Are all equipment within their current and voltage limits?
Can the system withstand stresses due a possible contingency (leading to a loss of equipment)?
Definition of states and control actions*
System operation in steady state is governed by equations which express:
(1) Real and Reactive power balance at each node (Equality Constraints )
Lecture 25 : Introduction
Objectives
In this lecture you will learn the following
Nature of Control Actions in a Power System
Brief recap on operating states and control actions
The role of the load dispatch center
Nature of Control Actions in a Power System
W hat we have learnt so far can be broadly classified as follows:
1. Frequency, voltage and power flow control
2. Real and Reactive power scheduling
Essentially, these are "routine" control actions of a manual controller (i.e., a system/plant
operator) or an automatic controller (like a generator terminal voltage regulator).
">These actions ensure a good quality supply (i.e., near-constant voltage and frequency) at a low cost.
">However, an important class of control actions are appropriate when a system is not in a "normal" state. To
understand this let us revisit a previous lecture on various operating states of a power system.
Operating states and nature of control actions (revisited)
The state (or condition) of a power system can be judged from the answers to the following questions:
Is the demanded load being met ?(i.e., is there a real and reactive power balance?)
Are all equipment within their current and voltage limits?
Can the system withstand stresses due a possible contingency (leading to a loss of equipment)?
Definition of states and control actions*
System operation in steady state is governed by equations which express:
(1) Real and Reactive power balance at each node (Equality Constraints )
