MINISTRY OF EDUCATION AND TRAINING VIETNAM ACADEMY OF SCIENCE
AND TECHNOLOGY
GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY
…………………………***………………………
Ng
NGUYEN TUNG LINH
BUILDING ARTIFICIAL INTELLIGENCE ALGORITHM FOR
RECONFIGURATION DISTRIBUTION NETWORK PROBLEM
Code major: Control theory and Optimization control
(Automation and Control Engineering Technology)
Code: 62 52 02 16
SUMMARY OF ENGINEERING DOCTORAL THESIS
Ha Noi - 2018
2
INTRODUCTION
1. Sep up the problem
According to the statistics of Vietnam Electricity Corporation, total power loss in recent
years is about 9-15% of electricity production volume, in which distribution of the electrical
network holds 5-7%. Then, researching methods for power loss reduction in the distribution
network is very urgent demand. Reconfiguaration distribution network is one of methods to
minimize power loss which is researched most.
Currently, solution of reconfiguaration distribution network problem is optimal one under
NP-hard class and then in order to solve this problem, there are some following methods to
approach and solve the problem:
- Seek by optimal mathematical method
- Seek heuristic to seek enough good solution.
- Seek near correct solution by natural emulation algorithm such as: Simulated Annealing
algorithm, genetic algorithm, herd optimum, etc.
2. Objectives and tasks of the thesis
Propose algorithm by Heuristic method to apply for the problem of reconfiguaration
distribution network with objective function for capacity loss reduction considered in the case
that there is/is not dispersal power connected into electrical distribution network
Research the effect of dispersal power when connect to the electrical distribution
network, affecting the network reconstruction problem.
Propose algorithm by new Meta Heuristic method for reconfiguration distribution
network problem with a goal of power losses reudction in the the case that there is/is not as well
as consideration to the location and capacity of dispersal power source when it is connected to
electrical distribution network.
3. Scope of research
Reconfiguaration distribution network problem with objective function of capacity loss
reduction in the case that there is/is not dispersal power source connected to the network.
The problem of electrical distribution network under consideration to the location and
capacity of dispersal power source when connect to electrical distribution network with
objective function of capacity loss reduction.
4. Researching method
The research is applied Heuristic method and artificial intelligence algorithm for the
problem of reconfiguaration distribution network
Use emulation method to check accuracy of proposed algorithms through checking
sample problems of IEEE
5. New points of the thesis: the thesis achieves some the following researching contents:
Propose method for the problem of reconfiguaration distribution network on “Heuristic”
experience rules with objective function of capacity loss reduction under the consideration of
two cases: there is not connection to dispersal power source and there is connection to dispersal
power source.
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Propose the improvement for algorithm of metallurgical emulation for the problem of
reconfiguaration distribution network with subjective function of power loss reduction.
Propose using genetic algorithm for the reconfiguarationin the consideration of the
location and capacity of dispersal power when connect to distribution network with objective
function of capacity loss reduction.
6. Practical value of the thesis: Researching results of the thesis achieved some practical
value in the problem of re-configuration solution and actual applications
The method which proposes by the way of researching Heuristic, again can affirm that
application of experience rules and optimal method for optimum problems are still used well in
some cases.
The researching method according to MetaHeuristic for the problem of electrical
network re-configuration is proposed by the author to use Simulated Annealing algorithm and
genetic algorithm for the problem of reconfiguaration distribution network with objective
function of capacity loss reduction in the case there is dispersal power and there is not dispersal
power as well as the case considered to the location, dispersal power capacity connected to
distribution network
This is supporting tool for deciding design and operation of distribution network when
participate into competitive electrical market.
7. Thesis layout: The thesis is divided into 4 chapters
Chapter 1: General view of distribution network and the problem of reconfiguaration
distribution network
Chapter 2: Heuristic method for the problem of electrical reconfiguaration distribution
network
Chapter 3: MetaHeuristic method for the problem of electrical distribution problem
Chapter 4: Genetic algorithm for the problem of Reconfiguaration distribution network in the
consideration of dispersal power planning
CHAPTER 1: OVERVIEW OF ELECTRICAL DISTRIBUTION NETWORK AND
THE PROBLEM OF ELECTRICAL DISTRIBUTION NETWORK RE-
CONFIGURATION
1.1 Introduction of electrical distribution network
1.1.1 Characteristics of electrical distribution network
Electrical distribution network is an important component in the supply of electricity from
the production site to the electricity consumers, spreading across the whole territory of the
country. The distribution network can be designed with a loop structure or a beam structure,
but for technical reasons and operating conditions, it is operated in a beam structure. Thanks to
the open operating structure, the relay protection system only uses over current relay.
Distribution network operating conditions must always meet the following conditions:
- Open operating structure
- All loads are provided with electricity, pressure drop within the allowed range
- The relay protection system must be changed suitably
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- Lines, transformers and other equipment are not overloaded
1.1.2 Introduction of electrical reconfiguration distribution network
a. Introduction of electrical reconfiguration distribution network:
Electrical reconfiguaration distribution network problem is the status control of switching
equipments in the distribution network, in some operation cases to ensure for some objectives.
b. Classification of electrical reconfiguaration distribution network
*Classification by objective function:
Problem 1: Determine electrical network by load diagram in certain duration for the operation
cost to be minimum.
Problem 2: Detetrmine non – changeable electrical network in certain duration for power loss
to be minimal.
Problem 3: Determine structure of electrical network at a certain time for capacity loss to be
minimal.
Problem 4: Re-configure distribution network to balance load (among lines, transformers at
stations) to improve loading capacity of electrical network.
Problem 5: Recover electrical network after incident or cutting off power for repairing
Problem 6: Determine structure of electrical network by many objectives such as: capacity loss
is minimum, highest loading balance, minimum loading transmission, minimum pressure drop
at the end of network concurrently happens out, affects of dispersal power source to re-
configuration electrical distribution network, etc.
Problem 7: Determine electrical network to ensure for objectives of power reduction and
stopping supply or improving reliability of power supply.
*Classification by researching methods:
Figure 1.3 Classification of reconfiguration distribution network by researching method
* Some researching results of reconfiguration distribution network
Problem 3 – Determination of reduction network structure
P is the most important
problem
The problem determines the structure of effective capacity loss reduction network –
problem is an important one, it is considered as one module to solve other problems in the
system of reconfiguration distribution network. It is proved through alogorithms of last
researches.
Problem 1 – Minimal function of operation cost
This objective function is very function with distribution network with flexible and low load
transmission cost in the operation; network structure can be changed in many times in the day.
This function is very suitable with distribution network with flexible and low load transmission
cost, network structure can be changed in many time in the day.
Classification of methods for electrical distribution network
reconfiguration solutions
Analytic method Heuristic method
(Experience law)
Meta Heuristic
(Use AI algorithm)
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Problem 2 – Minimal function of power loss
In the fact, evenly in developed industrial countries, load transmission cost affects greatly
the decision on network structure changes because sometime these costs are bigger than gained
benefits.
Thus, for problem 2 – Determine non-changeable electrical network structure in surveying
time for power loss to be minimal.
Problem 4 – Balance capacity among lines and transformer stations
This algorithm can be applied suitably for areas which are usually affected by overload or
incertain loads, In [91], Tim Taylor, etc.
Problem 5 – Re-structure distribution network after incident
This is objective which is mentioned by almost scientists in their researches.
Problem 6 – Re-structure network under objective function
In the operation of distribution network, there are many operation objectives which the
controlid must select suitably with characteristics of local electrical networks.
1.1.3 Current status of electrical distribution network in Vietnam
Current status of Vietnam’s electrical network
- By history of development and in each country, there many grades of distribution voltages
and these grades in regions are also different each other (6.6, 10, 15, 22, 35 kV)
- Recloser and loaded cutter (LBS) are not controlled remotely and quantity is not
considerable then switching cost is big and time for loading transmission is long.
Problems during the process of Vietnam’s electrical grip operation are presentated in
problem 1 to problem 7
1.1.4 Model of electrical reconfiguration distribution network
a. Mathematical model of reconfiguaration distribution network
For mathematics, reconfiguration network is the problem for planning discrete curvilinear
by the capacity line running on branches, at [78] the model as presented below.
Minimal function F =
n
i
n
j
ijij
n
i
n
j
ijijij LCRIC
1 11 1
2
(1.4)
Satisfying with:
n
1i jij DS
(1.5)
Sij Sij max (1.6)
DVij DVij max (1.7)
max.
t
f
n
t
ft
fSS
(1.8)
1
t
ft
f
(1.9)
Objective function is interrupted, it is very difficult to solve reconfiguration distribution
network by the method of mathematical analytics traditionally [11].
