Power System Planning in the Presence of Uncertainties

1.  Introduction about Uncertainties
 Power System Planning in Presence of Uncertainties
Content :

2. is a term used in subtly different ways in a number of
fields, including physics statistics economics engineering
and information science. It applies to predictions of future
events, to physical measurements that are already made, or
to the unknown. Uncertainty arises in partially observable
on different environments,
Introduction Uncertainty

3. 1.Measurement of Uncertainty: A set of possible states or outcomes where
probabilities are assigned to each possible state or outcome – this also
includes the application of a probability density function to continuous
variable
2.Measurement of Risk: A set of measured uncertainties where some
possible outcomes are losses, and the magnitudes of those losses – this also
includes loss functions over continuous variables

4. Uncertainty in Calculations
 to determine the uncertainty for a quantity that was calculated from one or more
measurements ,There are complicated and less complicated methods of doing this.
 The simple oneThe Upper-Lower Bounds method of uncertainty in calculations is not as
formally correct, but will do.The basic idea of this method is to use the uncertainty
ranges of each variable to calculate the maximum and minimum values of the function.
measurement = best estimate ± uncertainty

5. the area would be:
A = l * w = 1.2 * 1.3 = 1.56 m^2
Area Presence of Uncertainties
The minimum area would be using the "minimum" measurements so
l = 1.2 - 0.2 = 1.0
w = 1.3 - 0.3 = 1.0
So the "minimum' area is A-min = 1.0 * 1.0 = 1.0 m^2
Likewise for the maximum area, l = 1.2 + 0.2 = 1.4 and
w = 1.3 + 0.3 = 1.6
So the Maximum area is A-max = 1.4 * 1.6 = 2.24 m^2
We can say ¥ = ±(0.2)(0.3) = 0.6 the area is A = 1.5 +/- 0.6 m^2
For example you want to find the area of a square and measure one side as a length of 1.2 +/-
0.2 m and the other length as 1.3 +/- 0.3 meters,

6. power system planning namely,
• Base on Load forecasting (LF)
• Generations expansions planning (GEP)
• Substations expansion planning( SEP,)
• Network expansion planning (NEP)
• Reactive power planning (RPP)
We assumed, implicitly, that all decisions are made by a single entity and the information
used lacks any uncertainty. None of the above is strictly true.

7.  If Generations expansions planning is decided by some entities based on the
other entities cannot proceed towards the other steps (SEP, NEP and RPP) if
they cannot make sure what the GEP players do in actual life. Still, there are
more uncertainties involved for their various decision makings .
 The uncertainties play major roles in power system planning issues of the new
environment.

8. Power System regulating industry
 In the regulated industry, power system structure consists of
 generation, transmission and distribution owned by a single entity;or owned by different owners,
controlled or regulated by a single entity.
 the single entity decides on where and how to allocate generation and/or transmission facilities.
The investment and the operational costs as well as an appropriate level of profit for the owners are
are compensated by regulated tariffs imposed on the customers.

9. Power system in de-regulated
In de-regulated environment,
 The electricity is provided by some suppliers known as generation companies ( Gen.Co)$
 The customers may wish to buy this commodity either from the high voltage or low voltage
(through distribution companies also called (Dis.Cos),may be Owned by transmission company
 electricity should be transferred from the suppliers to the customers through the available
transmission facilities (transmission lines and/or cables, ) That owned by the transmission
company and also called (TransCo)

10.  The other facilities have to be owned investments or (owned by the
transmutation companies (TransCo ) is still fully or partially
 The electricity price is determined based on by suppliers from one side and
customer from other

11. de-regulated environment,
Generationcompany
Transmission line company
Distribution company
customers
Reactive power

12.  Two terms of uncertainty and risk are widely used in power system planning . There are no
fixed definitions for these terms. Some believe that they are the same, while some believe
one is the result of another. Still, some think of these to be quite independent..
 we assume that the uncertainties involved may result in risk. For instance, as GEP, SEP and
NEP are based on the forecasted load,
 any uncertainty in the forecasted load may result in risk so that the network planned may be
unable to fulfill its functions properly to supply all loads
 On the other hand, the uncertainties affect all short- power system planning and long- power
system planning decisions.
Power System Uncertainties

13. 1 Uncertainties module in a Regulated Environment
 power system planning is depend on load forecasting (LF) and consists of
GEP, SEP, NEP and RPP, input parameters.
 The studies are to be carried out for some years in the future depended on
historical information so the input parameters should be, accordingly,
predicted
 these parameters are in turn, dependent upon some other parameters. As a
a result,
 the input parameters to power system planning modules may face
uncertainties which obviously affect our decisions

14. Power planning modules input parameters are
 Economic growth load forecasting (LF)
 Economic parameters, such as inflation, depreciation and interest rates of
• Load forecasting (LF)
• Generations expansions planning (GEP)
• Substations expansion planning( SEP,)
• Network expansion planning (NEP)
• Reactive power planning (RPP)
• The Fuel cost (directly on GEP and indirectly on SEP, NEP and RPP

15.  Technological developments (LF, GEP, SEP, NEP and RPP)
 Environmental limitations (directly or indirectly)
 Investment costs (GEP, SEP, NEP and RPP)
 Demand side management programs (LF)
 Operation and maintenance costs (GEP, SEP, NEP and RPP)
 Resource (such as fuel and water,) availability (GEP)

16. Mane company or entity
transmission line Generations Distribution
regulated environment

17. 2-Uncertainties module in De-regulated Environment
 The power system de-regulating has resulted in appearing new independent
entities such as (GenCos, TmnsCos, DisCos,.)
 The single-player environment has replaced by a multi-player, with its risks
and uncertainties involved.
 each aiming at making, the maximum profit (revenues minus costs) from
its properties.
 The de-regulation of the power industry leads to separation of the
transmission planning from the generation expansions. This will increase
the uncertainties and challenges

18.  Each entity now should make its own decisions. And how to behaviors
with the other players into consideration in this new situation,
 The electricity price is determined based on the supply-demand rule.
 We discuss differentiate between the uncertainties involved in GEP
from one side and, TEP) from the other side.

19. Uncertainties in Generations expansions planning
GEP
 This uncertainty introduced for the regulated environment, as
an owner should now make its own decision in investing on a
power plant, it new uncertainties.
 The electricity price is the most important If investor may
invest in a location with an anticipated high electric price.
However, the behaviors of the other players should also be
predicted and taken into account. This prediction is not an easy task
at all

20.  uncertainties more effects in the de-regulated environment For example ,
the costs of primary resources (such as gas, oil, etc.) may make an owner
to defer its investment in a place or changes its decision and invests in
another place.
 In a regulated environment, although these costs are still effective, the
investor may still invest at the same place and time; as the money is
guaranteed to be back by some appropriate tariffs.

21. Uncertainties in transmission line expansion
planning TEP
• This uncertainties in a regulated environment,
• Deal with how transmission line expansion planning may be properly
performed
• the most important uncertain factor which influences TEP ,the
uncertain GEP output.
• If GEP is decided upon by the other market players As the costs of
TEP should be recovered from the market participants (both the
suppliers and the customers)

22. • an over design may result in players dissatisfactions or uneconomic
decision .
• Under design can result in similar effects as the suppliers may be
unable to sell or cover the loads of the customers

23. Advanced of calculate Uncertainties in power
planning
 Reduced the risk and error
 more accuracy Measurements for planning
 Give robust power planning
 Give more reliably for power system for short and long planning

24. Thank for listing

25. Reference
1- Hossein Seifi • Mohammad Sadegh Sepasian electric power planning Issues, Algorithms
and solution chapter 11 section 11:1 -11:4
2- http://www.ivsl.org/?language=en