1.Power Scenario in Indian Grid 2.Growth of Electricity Consumption 3.NLDC & RLDC 4.Speed Governor 5.Regulation of two generators in parallel 6.Load forecasting and its classification 7.Unit commitment and its constraints 8.Load Scheduling/Load dispatching

1. ANNAI VAILANKANNI COLLEGE
OF ENGINEERING
P M ANSHO
Assistant Professor
Dept of EEE

2. COURSE PROFILE
Course Code/Name : EE8702/POWER SYSTEM OPERATION AND CONTROL
Course conducting Year : IV Year (7th Semester)
Course Instructor : Mr. P M ANSHO
Regulation : 2017
EE8702-PSOC

3. LEARNING OBJECTIVE
• To understand the operation and control of power systems
• To have well thorough knowledge on economic operation of power
systems, scheduling of hydro-thermal power plants.
• To model the power system components like turbine, Governor and
excitation systems
• To apply shunt and series compensation of transmission lines in real world
electrical applications
• To design the single area and two area thermal power system.
• To solve economic dispatch, unit commitment, load frequency control and
automatic voltage generation using conventional method
• To understand the significance of reactive power control in power systems
to maintain quality of power
• To design appropriate control scheme to compensate reactive power
EE8702-PSOC

4. COURSE OBJECTIVE
To impart knowledge on the following topics;
 Significance of power system operation and control.
 Real power-frequency interaction and design of power-frequency
controller.
 Reactive power-voltage interaction and the control actions to be
implemented for maintaining the voltage profile against varying system
load.
 Economic operation of power system.
 SCADA and its application for real time operation and control of power
systems
EE8702-PSOC

5. SYLLABUS
Module 1: PRELIMINARIES ON POWER SYSTEM OPERATION AND
CONTROL
Power scenario in Indian grid-National and Regional load dispatching
centers-Requirements of good power system-Necessity of voltage and
frequency regulation-Real power vs frequency and reactive power vs
voltage control loops-System load variation, load curves and basic concepts
of load dispatching-Load forecasting-Basics of speed governing
mechanisms and modeling-Speed load characteristics-Regulation of two
generators in parallel.
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6. Power scenario in Indian grid
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7. Growth of Electricity Consumption in India(as on 31/03/2019)
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11.  National Load Dispatch Centre
 Northern Regional Load Dispatch Centre
 Eastern Regional Load Dispatch Centre
 Southern Regional Load Dispatch Centre
 Western Regional Load Dispatch Centre
 North-Eastern Regional Load Dispatch Centre
National and Regional load dispatching
centers
EE8702-PSOC

12. Requirements of good power system
• The continuity in the power supply must be ensured.
• The specified consumer voltage must not vary more
than the prescribed limits.
• The efficiency of the lines must be as high as
possible.
• The system should be safe from consumer point of
view.
• The lines should not be overloaded.
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13. Need for Voltage & Frequency
Regulation
• Good quality of power supply
• Voltage variation 5%
Voltage Regulation:
 Transmission and distribution lines needs voltage control
 Below voltage-Reduces light output & above voltage- reduces life for
lamps
 Below voltage- draws high current for motors
 Performance suffers and life expectancy drops
 Below certain limit- instability, Above – overheating for Generator
 Service voltages - +/- 5%
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14. Frequency Regulation
 Helps in maintaining system frequency
 Speed within limit under fluctuating load
 Governor & Integral controller
 Drop in frequency-High magnetizing current
 Better operation , if frequency error is in limit
 Speed of AC motor-Frequency
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15. System Load Variation
System Load
• Domestic
• Commercial
• Industrial
• Agriculture
• Others - street lights, traction.
System load characteristics
• Connected load
• Maximum demand
• Demand factor
• Average load
• Load factor
• Diversity factor
• Plant capacity factor
• Plant use factor
The variation of load on power station with respect to time.
EE8702-PSOC

16. Load frequency & Dispatch control
Load frequency
• Sense the bus bar frequency & power frequency
• Difference fed to the integrator & to speed changer
• Tie line frequency maintained constant
Economic dispatch control
• When load distribution between a number of generator units considered
• optimum schedule affected when increase at one replaces a decreases at
other.
• Optimum use of generators at each station at various load is known as
economic dispatch control.
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17. System voltage control
 Static VAR compensator
 Synchronous condenser
 Tap changing transformer
 Switches
 Capacitor
 Reactor
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18. Governor
 Frequency control
 Automatic voltage control
Speed Governing Mechanism
• Speed Governor
• Governor Controlled Valves
• Speed Control Mechanism
• Speed Changer
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19. Regulation of two generators
in parallel
• Generator sets are operated in parallel
• To improve fuel economy and reliability of the power supply.
• Economy is improved with multiple paralleled generators by selecting only
sufficient generators
• To carry the load demand at any given time.
• By operating each generator near its full capacity, fuel is utilized efficiently.
• Power system reliability is improved.
• Protective systems can be designed to detect a faulty element.
• Multiple generator installation has become common in applications for
standby and prime power, portable and stationary power, commercial and
military power.
• Operating generators in parallel required attention to the two control
systems
• It is limited to the control of the voltage regulator.
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20. Load Forecasting
• For proper planning of power system
• For proper planning of transmission and distribution facilities
• For proper power system operation
• For proper financing
• For proper manpower development
• For proper grid formation
• For proper electrical sales.
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21. Classification of Load Forecasting
1. Demand forecast
To determine the capacity of the generation, transmission, and
distribution system additions.
2. Energy forecast.
To determine the type of facilities required,i.e., future fuel
requirements
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23. UNIT COMMITMENT
• Unit commitment (UC) is a popular problem in electric
power system that aims at minimizing the total cost of power
generation in a specific period, by defining an adequate
scheduling of the generating units. The UC solution must
respect many operational constraints.
• Unit commitment (UC) is an optimization problem used to
determine the operation schedule of the generating units at
every hour interval with varying loads under different
constraints and environments
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24. Constraints In Unit Commitment
• Spinning Reserve
• Thermal Unit Constraints
 Minimum up time
Minimum down time
• Other Constraints
Hydro constraints
Most run
Fuel constaint
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25. Load Scheduling(Load Dispatching)
Loading of units are allocated to serve the objective of minimum
fuel cost.
i) Thermal Scheduling:
• Loading of steam units
• Objective of minimum fuel cost
ii) Hydrothermal Scheduling:
• Loading of hydro and thermal units
• Scheduling of hydro units are complex
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26. Types of Hydro Scheduling:
i) Long range hydro Scheduling
• Involves from 1 week to 1 year or several years.
• Optimization of statistical variables
ii) Short range Hydro Scheduling
• Involves from 1 day to 1 week or hour by hour scheduling.
• Optimization of statistical variables
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