1ST IAT PSP (10EE761) SCHEME OF SOLUTION
1(a) two load forecasting techniques
i)
Moving Average: (02 marks)
Each point of a moving average of a time series is the arithmetic or weightened
average of a number of consecutive points of the series, where the number of data
points is chosen so that the effects of season or irregularity or both are eliminated a
minimum of two years of past energy consumption is desirable, if seasonal effects are
present. Otherwise, there will be less data.
ii)
Trend Projections: (02 marks)
This technique fits a trend line to a mathematical equation and then projects it into the
future by means of this equation.
Trend analysis is the study of the behavior of a process in the past and its
mathematics modeling so that future behavior can be extrapolated from it.
Two general approaches followed for trend analysis are:
i)
The fitting of continuous mathematical functions through actual data to
achieve the least overall error, know as regression analysis.
ii)
The fitting of a sequence on discontinuous lines or curves to the data.
A time varying event such as power system load can be broken down into the
following four major components:
i)
Basic trend
ii)
Seasonal variation
iii)
Cyclic variation which includes influences longer period.
iv)
Random variations.
1(b) LEAST COST PLANNING. (02 marks)
Two inherent problem in traditional planning, first is demand forecasting and investment
planning. Second is shortage of resources. No attempt is made to understand the extent of
unmet demand, nor the extent to which price would influence demand growth.
Least Cost Planning is strategy to provide reliable electrical services at the lowest overall cost
with a mix of supply side and demand side resources. system expansion detailed project reports
(DPRs) must be based on Least Cost Planning and need to be mandatory by amending the
ELECTRICITY SUPPLY ACT, 1948.
(1.5 marks)
ATTRIBUTES
OPTIONS (PLANS)
LEAST COST
PLANNING
PROCESS
REGULATIONS
VARIOUS OPTIONS: (03 marks)
Economical: debt and equity, interest, off- peak electricity sale.
Supply Side: Conventional plants, combined cycle combustive gas turbine, hydro large including
pump storage, non- conventional plant, geo-thermal, biomass gasification,,DG etc.
Demand side: load management, cogeneration, captive generation, time of day metering,
effective use of energy, etc.
2(a) CO-GENERATION
Nearly 5000 MW of power can be generated in India through Co-Generation from industries
like, sugar, textile, alcohol, paper, petro-chemicals and metallurgical. For heavy industries like
cement, steel, aluminum, fertilizers, chemical plants and other heavy users to install captive
power generation.
i)
A cogeneration facility produces electrical energy and other forms of useful thermal
energy.
ii)
Cogeneration is not a new technology, the modern technology is more efficient
having steam pressure of minimum 45 kg/cm2 and high temperature up to 500oC.
TOPPING: primarily electricity is generated then liberated heat is used for other heat
process.
BOTTOMING CYCLE: first heat process is carried out then electricity is generated.
2(b) STRATEGY FOR TRANSMISSION EXPANSION (3.5 marks)
While SEB’s are responsible for providing the transmission systems for their respective grids,
power grid has been entrusted with the responsibility for laying transmission system network
for facilitating transfer of power. Formation of national power grid to facilitate transfer of
power not only within a region but also across various regions of the country. According to IEA
1910 and electricity supply act 1948, private transmission companies can be entrusted for
developing any transmission system.
DISPATCHABILITY (03 marks)
LOADING i) The transmission system should be planned on the basis of regional self-sufficiency.
ii)
The transmission system should be capable of transmitting, the states share from
the central sector common projects.
iii)
The transmission system should be planned to withstand outage of two circuits of
220 kV, or one circuit of 400 kV.
iv)
The transmission system should be planned to ensure full evacuation of power from
generating stations.
v)
No transmission constraint on rescheduling generation.
vi)
Reactive power compensation should be provided in lower voltage systems.
3(a)
i)
PLANNING TOOLS (any 02 each tool 02 marks)
Simulation Tool: These simulate the behavior of the system under certain conditions
and /or calculate relevant indices. Ex: load flow models, SC models, transient
stability models etc. the use of simulation tools for strategic planning need
voluminous data and requires the results from various models to be integrated.
ii)
Optimization Tool: these minimize or maximize an objective function by choosing
adequate values for decision variables. Ex: optimum power, least cost expansion
planning, generation expansion planning.
iii)
Scenario Techniques: it is a method for viewing the future in a quantitative fashion. A
narrative describing the probable or possible sequence of events is developed. The
events are either sequentially or simultaneously recorded and built up into a case
history or a story. All possible outcomes are verified/ investigated. The sort of
decision or assumptions which might be made by a utility developing such a scenario
might be: should we computerize and automate the management of power system
after a certain date. How can we meet the power demand by the year AD 2020.
3(b)
Distributed power generation located close to the loads can follow the local load, minimizing the
heavy loading of the transmission grid. (01 mark)
(1.5 marks)
ATTRIBUTES
OPTIONS (PLANS)
POWER UTILITY
PLANNING
PROCESS
REGULATIONS
PLANNING OPTIONS (02 marks)
a) GENERATION STATION PLANTS:
Hydro, coal, oil, gas, nuclear.
b) Modular of packaged plants:
Fluidized bed combustors, fuel cells, combustion turbines.
c) Demand Side Management:
Active, passive control, co-gen, captive generation, pumped hydro plants.
d) Renewable sources: solar, wind, geothermal, hydro, biomass.
UNCERTAINITIES: (02 marks)
Load growth, fuel price and water availability for hydr plants, construction cost, consumer response to
dsm, performance of life extended or converted plants, market for off peak sale, technological
development, regulatory changes.
ATTRIBUTES: (02 marks)
a) Economic: tarrif impact, revenue requirement.
b) Quality: reliability
c) Financial: cash flow, construction expenditures.
d) Environmental, emissions, right of way requirements.