Power Plant Instrumentation

MEASUREMENT DONE IN POWER PLANT

Process measurements : Pressure, Temperature, Flow and Level.

Analytical measurements (SWAS) : pH, Conductivity, Silica, Hydrazine and Dissolved Oxygen.

• Condition monitoring measurements for rotating equipment : Vibration, speed, bearing temperatures, eccentricity, axial shift, displacement.

• Emission monitoring (CEMS): CO, SOx, NOx

• Environmental measurements : Wind velocity, Ambient temperature, Humidity, Rainfall etc.

MEASUREMENT PARAMETER• Indication of the

parameter - can be either LOCAL or REMOTE

• LOCAL means indication of the parameter at the field by a dial type gauge, liquid level gauge or flow glass.

• REMOTE means that the primary signal is converted to an electrical analog signal and transmitted to the control room for indication / control.

WHAT IS CONTROL SYSTEM?

CONTROL SYSTEM• A control system is a device

or set of devices to manage, command, direct or regulate the behavior of other devices or systems.

• There are two common classes of control systems, with many variations and combinations: logic or sequential control and feedback or linear controls. There is also fuzzy logic, which attempts to combine some of the design simplicity of logic with the utility of linear control.

Why DCS?• High Reliability• Improved Response Time• Improved Interface to

plant• Improved accessibility of

plant data to engineering and management personnel.

• Historical Storage and Retrieval System

• Safe operation of Plant• Lowest Cost of Generation• Longest Equipment Life• Minimum Environmental

Effect• Maximum Efficiency• Energy Conversation

DISTRIBUTED CONTROL SYSTEM• DCS refers to a

control system usually of a , process or any kind of dynamic system, in which the controller elements are not central in location (like the brain) but are distributed throughout the system with each component sub-system controlled by one or more controllers.

DCS IN POWER PLANT

• The control system is responsible for controlling action of all the measurement.

• In power plant this DCS (Distributed Control System ) plays the role of this control system.

• All interlocking, monitoring and annunciation operations are performed in DCS.

Discrete (PLC)

Discrete (PLC) Continuous

(DCS)

Discrete (PLC)

Discrete (PLC)

Discrete (PLC)

Discrete (Custom)

DISTRIBUTED CONTROL SYSTEM

DCS HARDWARE

• Controller card• Input Cards (4-20 m A) Thermocouple, RTD, SOE Output Cards(4-20 m A,

Digital) Power Supply Module Communication Card

Cables• Controller with I/O

card

PLC’s for sequential control

Motion controllers for motion control

DCS systems for process control

Drive systems for drives control

DIFFERENT CONTROL SYSTEM INPOWER PLANT

CONTROL ROOM IN POWER PLANT

OPERATOR WORK STATION

Alarm MonitoringMimic Or Graphic DisplayTrend DisplayOperator Guidance DisplaySystem and DiagnosticDisplayControlBar ChartSequence DisplayFault Analysis Display