Module 6 : Preventive, Emergency and Restorative Control
Lecture 26 : Power System State Estimation
Objectives
In this lecture you will learn the following
The fundamentals of Power System State Estimation
Handling errors and bad data in static state estimation
Dynamic Measurements
Power System State Estimation
Power System State Estimation is a process whereby telemetered data from network measuring points to a
central computer, can be formed into a set of reliable data for control and recording purposes.
A static state estimate is obtained from measurements taken within a time interval of about 0-5 s. This is the
commonly used state estimator. Obviously, a state estimator of this type essentially gives a steady state
snapshot of the system.
A dynamic state estimate is obtained from measurements in a relatively shorter time (say 0.01 s). Moreover, all
such measurements are synchronised or "time stamped" using a common clock and communicated from
geographically distant locations to a load dispatch centre. These measurements could be used for advanced
control schemes which we shall see later.
The main concern in state estimation is the reliability of the measured data. Usually to minimize the errors, the
data is crosschecked using more measurements than necessary (redundant measurements). This is done in a
systematic fashion as discussed in the following slides.
Static State Estimation Procedure
We will try to understand the procedure in an informal fashion. Consider the simple system shown below:
Lecture 26 : Power System State Estimation
Objectives
In this lecture you will learn the following
The fundamentals of Power System State Estimation
Handling errors and bad data in static state estimation
Dynamic Measurements
Power System State Estimation
Power System State Estimation is a process whereby telemetered data from network measuring points to a
central computer, can be formed into a set of reliable data for control and recording purposes.
A static state estimate is obtained from measurements taken within a time interval of about 0-5 s. This is the
commonly used state estimator. Obviously, a state estimator of this type essentially gives a steady state
snapshot of the system.
A dynamic state estimate is obtained from measurements in a relatively shorter time (say 0.01 s). Moreover, all
such measurements are synchronised or "time stamped" using a common clock and communicated from
geographically distant locations to a load dispatch centre. These measurements could be used for advanced
control schemes which we shall see later.
The main concern in state estimation is the reliability of the measured data. Usually to minimize the errors, the
data is crosschecked using more measurements than necessary (redundant measurements). This is done in a
systematic fashion as discussed in the following slides.
Static State Estimation Procedure
We will try to understand the procedure in an informal fashion. Consider the simple system shown below:
