This document discusses national and regional power system planning in India. It begins with an introduction to power system planning, including transmission versus distribution planning and long-term versus short-term planning. It then covers various aspects of planning such as generation planning, capacity resource planning, and transmission planning. The document outlines the five electricity regions in India and discusses the economic benefits of regional coordination in planning. It concludes with mentions of integrated resource planning and least cost utility planning strategies.
1. GOVT. WOMEN ENGINEERING COLLEGE, AJMER
Presentation On:
NATIONAL AND REGIONAL PLANNING
PRESENTED TO: PRESENTED BY:
Mr. Anant Gupta Jyoti Garg
Khushi Lohia
Monika Tailor
Nisha Dangi
2. CONTENT:
INTRODUCTION
POWER SYSTEM PLANNING
TRANSMISSION VERSUS DISTRIBUTION PLANNING
LONG TERM VERSUS SHORT TERM PLANNING
ISSUES IN TRANSMISSION PLANNING
GENERATION PLANNING
CAPACITY RESOURCE PLANNING
TRANSMISSION PLANNING
NATIONAL AND REGIONAL PLANNING
3. INTRODUCTION:
Planning is the process of selecting vision, values, mission and objectives and
deciding what should be done to attain them.
The elements may be:
• Generation facilities
• Substations
• Transmission lines and/or cables
• Capacitors/Reactors
Planning is the process of taking a careful decision.
4. The decision should be:
Where to allocate the element (for instance, thesending and receiving end
of a line).
When to install the element (for instance, 2018).
What to select, in terms of the element specifications (for instance, number
of bundles and conductor type).
5. Transmission Versus Distribution Planning :
Three main levels for a power system structure, namely, transmission, sub-
transmission and distribution.
Distribution level is often planned or at least operated, radially.
6. Long-term Versus Short-term Planning:
Power system planning issues may cover a period of 1–10 years, or even more.
For the peak loading condition of the coming year, a power system utility
expert notices that from the two lines, feeding a substation, one would be
overloaded by 10% of its rating, while, the other would be loaded by 60% of its
rating.
If a control device is installed on one line, the load distribution may be
balanced on both lines.
Once decided, the installation process of this device can be performed in such
a way that no problem arises for the coming year.
7. This is a typical short term transmission planning decision.
The load forecasting for the coming years shows that with all already available and
planned generations, there would be a shortfall of generation in 9 years from now,
onward.
After a careful study, the planner decides on adding a new 500 MW steam power
plant at a specific bus in that year.
Its construction should start well in advance so that it would be available at the
required time.
His or her decision is a typical long-term (9-year) transmission planning decision.
8. Basic Issues in Transmission Planning:
Load Forecasting
The first crucial step for any planning study is to predict the consumption for the study
period (say 2015–2020), as all subsequent studies will be based on that.
However, it is understood that a short-term load forecasting, used for operational studies,
is significantly different from the long-term one used in planning studies.
In a short-term load forecasting, for predicting the load for instance, of the next week,
we come across predicting the load for each hour of the coming week.
It is obvious that the determining factors may be weather conditions, special TV programs
and similar.
Obviously, the determining factors are different here i.e. Population rate increase, GDP
(Gross Domestic Product) and similar terms have dominant effects.
9. Generation Expansion Planning:
After predicting the load, the next step is to determine the generation
requirements to satisfy the load.
An obvious simple solution is to assume a generation increase equal to load
increase.
If, for instance, in year 2015, the peak load would be 40,000 MW and at that
time, the available generation is 35,000 MW, an extra generation of 5,000 MW
would be required.
10. Substation Expansion Planning:
Once the load is predicted and the generation requirements are known, the next step is to determine
the substation requirements, both, in terms of
Expanding the existing ones
Installing some new ones
This is referred to as Substation Expansion Planning (SEP).
SEP is a difficult task as many factors are involved such as
Those constraints due to the upward grid, feeding the substations,
Those constraints due to the downward grid, through which the substation supplies the loads,
Those constraints due to the factors to be observed for the substation itself.
11. Network Expansion Planning:
Network Expansion Planning (NEP) is a process in which the network
(transmission lines, cables, etc.) specifications are determined.
In fact, the network is a media for transmitting the power, efficiently and in
a reliable manner from generation resources to the load centers.
12. Generator planning:
Load Forecasting
In the short term, load can be forecast with great accuracy, and this is
performed daily to determine generation units’ commitment.
Load forecasting for the purpose of generation planning, however, requires a
substantially longer time horizon, because system expansion projects require
long lead times, often between 2 and 10 years.
The outputs from a load forecast are a forecast of annual energy sales (in
kilowatt-hours), and the annual peak demand (in kilowatts).
There are two widely used methods in energy sales forecasting, econometric
regression analysis, and end- use electricity models.
13. The usefulness of each method depends on data availability, customer
segmentation, and the degree of detail required.
End-use electricity models are physical, engineering based methods that
often are used in forecasting the residential load, and sometimes for
commercial and industrial loads.
Forecasting the peak demand is done based on forecasted energy sales
by multiplying forecasted energy with an empirically determined load factor
coefficient.
Peak load is extremely sensitive to weather, and both the historic data
and the forecast must be adjusted consistently to normalize them relative to
the weather.
Peak load forecasting is important because it directly influences the
required generation capacity—on every day of the year there must be enough
available generation to feed the peak load.
14. Reactive Power Planning:
In running NEP, the voltages are assumed to be flat (i.e. 1 p.u.) and reactive power flows
are ignored.
The main reason is the fact that constructing a line is not considered as a main tool for
voltage improvement.
Moreover, the running time of NEP can be exceptionally high or even the solution may
not be possible if AC Load Flow (ACLF) is employed. That is why in practice, NEP is
normally based on using Direct Current Load Flow (DCLF).
Upon running GEP, SEP and NEP, the network topology is determined.
However, it may perform unsatisfactorily, if a detailed AC Load Flow (ACLF) is
performed, based on existing algorithms.
15. To solve such a difficulty, static reactive power compensators, such as capacitors and
reactors may be used. Moreover, some more flexible reactive power resources are
required. The problem is, however
Where to install these devices?
What capacities do we have to employ?
What types do we have to use?
16. Capacity Resource Planning:
The question of what type of generating station (hydroelectric, nuclear, coal,
gas turbine, or other) would be the most economical addition to the system is
answered by combining a production cost analysis with an investment cost
analysis.
The evaluation begins by preparing a set of expansion scenarios.
An expansion scenario includes additions of multiple units and the planners are
required to hypothesize the type and the number of units that should be
considered.
The scenarios then are evaluated one at a time, beginning with a multiyear
reliability simulation to determine the LOLP index for each year of study.
If the reliability requirements are not met they often can be improved either
by advancing the installation dates of some units, or by delaying retirement
dates of others.
17. Transmission Planning:
• A transmission system makes it possible to supply loads from the most
economical sources of power, and operate generating stations flexibly and thus
improve overall system reliability.
• Transmission planning therefore ensures that the transmission infrastructure
can deliver power from the generators to the loads, and that all the equipment
will remain within its operating limits in both normal operation and during
system contingencies.
• Contingencies in this context mean unexpected failures of any system element;
for example a generator or a transmission line could have an unexpected outage,
which would force the remainder of the system to transition to a new operating
point.
18. NATIONAL AND REGIONAL PLANNING:
There is a lot of diversity in the country in topography, daily peak due
to date and difference in annual peak load timing( winter or summer)
and resources in various regions.
Hence, the five electricity regions have been established.
The economic Arguments in support of regional coordination are:
A. Such coordination allow join planning and operation of facilities.
B. It makes exchange of economical energy easier.
C. It prevents construction of unneccessary facilities by isolated
system.
19. More specifically, as a result of transmission, coordination offers distinct
economic and the none –coincidental occurrence of the peaks of participation
system.
It might be possible to reduce the total generating capacity requirements
capacity that would otherwise applied if each utility system were fully meet
its need.
By combining the existing capacity of different utility, it is possible to reduce
the required reserve capacity of generation in the region and to make
economic use of the generation resources such as hydro and fossil fuel.
One of the problems in regional planning relates to coordination among the
various utility in the region with respect to tariff and backing down of
generating units in merit order.
HVDC links for transfer of power between various regions is desirable in order
to utilize surplus power in some regions and for stable grid operation.
20.
21.
22. FIVE ELECTRICITY REGIONS ARE:
A. Northern Region
B. Western Region
C. Southern Region
D. Eastern Region
E. North Eastern Region
25. Least cost utility planning:
There are two fundamental problems inherent in traditional planning.
The first is – the demand forecasting and investment planning are treated as
sequential steps in planning.
The second is – that planning efforts are inadequately directed at the main
constraints facing the sector like the serious shortage of resources.
Least cost planning is least cost utility planning strategy to provide reliable
electrical services at the lowest overall cost with a mix of supply side and
demand side resources.