The Silk Road Model
for the Study on Environmental Effect and Strategy
of Power Generation in Asia to the Year 2030
(Panel Session in IEEE PES 98 SM)
Fumio Arakwa
Member of JNC for ICEE, Masakazu
Kato Member of JNC for ICEE,
1. Methodology and Perspectives
The importance of studying a global power system
is now deeply understood among people in the world,
as has discussed on many well known occasions. (1)
Electric power is one of the most efficient and
safest energies in the modern society. Accordingly,
interconnection of electric power systems will go
a long way as an environmental protective measure,
if it is designed to meet the needs of society in
the future.
However, we must be careful that such an important
issue as "environmental effect and strategy of power
generation in Asia to the year 2030" should not be
discussed in a sensational or political manner. Discussions
must be grounded in sound data and facts.
This paper provides the public with a tool for rational
and fruitful discussion of the issue: the computer
model composed of mathematical formula which deal
with reasonable and practical data.
The computer model is a flexible decision support
system, under the uncertainty that can be used in
discussions between decision makers and specialists
for issues like power systems interconnection, because
participants can exchange practical views and rational
opinions on the data and scenarios shown on the view
panel.
Every engineer interested in the subject of power
systems interconnection must know that organizers
of both IEEE and CIGRE activities are very attentive
to the subject and have held several sessions and
symposia in this field, e.g. the CIGRE Bangkok Symposium
1989, "Operation of electric Power Systems in Developing
Countries" and the panel in IEEE 96 SM, "African Electricity
Infrastructure, Interconnection and Electricity Exchanges."
In the session entitled "Project Development." Chaired
by Mr. Arakawa, at the International Symposium on
"Sustainable Energy Development in Asia" (Hong Kong,
9th May 1996) Mr. Prutichai of EGAT introduced eight
interconnection projects initiated by ASEAN member
countries in 1982 and highlighted the difficulty of
promoting the ASEAN Grid Project due to geographical
and financial constraints, low load demand and dependency
on power plant projects. (2)
In August 1996 ICEE '96 was held in Beijing at which
time a panel under the title of "Interconnection of
power grids" was organized and four papers from China,
Korea, Russia, and Japan were presented. Mr. Zheng
Meite (CEPRI) focused on the energy excess in Siberia
and the shortage in North China expected the year
2000 and 2010 (3)
Dr. Sae-Hyuk Kwon (KU), et. al., of Korea cited
the current loosening of socio-political tensions
in Korea could be a positive stimulus to promote the
program. He recommended that ICEE create a Working
Group for the promotion and study of the Far East
Asian Interconnection to encircle the Japan Sea with
transmission lines and cables. (4)
Mr. N. I. Voropai and G. V. Shutov (SEI) Focused
on energy resource allocation and load curve difference
between widely separated areas on the Eurasian Continent.
They estimate 15GW of potential power exchanges between
East Siberia and Japan, 18-20GW of potential savings
in the installed capacities in Japan. (5)
Mr. Arakawa (EPDC) discussed interconnection as follows:
It is now quite important to study global power systems
not only for technical reasons but also for the sake
of environmental protection. Interstate power grid
interconnection is technically and financially feasible,
when a project is commercially attractive. As the
difficulty is composed of social, political and cultural
factors, mutual understanding among peoples concerned
will be the key to the success. Electrical engineers
are supposed to provide people at the socio-political
level with reliable data for the project. The Japanese
people are eager to contribute to the peace and prosperity
of the world. (6)
2. Technology to Support the plan
The electricity trade is quite popular and productive
in Western Europe and between Canada and the US because
both of these areas geographically close, economically
interdependent and share similar political orientation
and cultural heritages. Also, it must be pointed out
the HVDC technology provides a reliable infrastructure
which facilitates an interconnected system.
In Korea recently, an interconnection system with
HVDC of 150MW was put into service between the Peninsula
and Cheju island. In China, it is considered a magnificent
milestone in the history of power development that
a +- 500kV HVDC project was successfully completed
to transmit power from Gezhouba Hydro-power Plant
to Shanghai, interconnecting the two major regional
networks of Central China and East China. In Japan,
the Kii Channel HVDC Link, with 48 km of 500kV submarine
cable. 51 km of overhead line and 2800MW converter
stations, is currently under construction and planned
for completion in the year 2000. This follows the
successful connection of Hokkaido-Honshu with an HVDC
link in 1979.
Due to the development of semiconductor technology,
high power self-turn off devices such as GTO (Gate
Turn Off Thyristor), which can turn off current at
any time are now available. Because the self-communication
converter is operated by the voltage source, it has
several advantages over the HVDC system with conventional
line commutation converters.
The self-commutation converter technology has been
applied to the Static Var Compensator (STATCOM), Eight
GTOs of 6kV-2.5kA for a 50 MVA STATCOM at Shin-Shinano
substation, installed in 1993, are connected in series
to reach DC 16.8 kV and operated with high reliability.
As an example of its application to HVDC and FACTS
(Flexible AC Transmission Systems), the control strategy
for multinational HVDC with self-commutation converters
has already been developed and reported.
At present, the losses and the costs of self-commutation
converters are higher than that of line commutation
converters. However, significant development in self-commutation
converter technology, as well as semiconductor technology,
promise to make self-commutation converters economically
feasible in the coming years. Interstate interconnections
will be even more advantageous due to the application
of these advanced technologies in the near future.
(7)
Due to its remarkable characteristic of "zero resistance."
SC (superconductivity) is another important and effective
technology in establishing a reliable and sophisticated
power system, particularly in terms of long-distance
interconnection. Though high temperature SC material
is not yet produced industrially, SC will play an
active role in various aspects of power systems and
social life in the form of SC generators, SC cables,
SC converter stations, SMES and medical facilities,
electronic equipment for multimedia systems, etc.
The characteristics of SC are not limited to "zero
resistance." There is much to be gained from utilization
of other SC characteristics such as pinning by magnetic
force and Josephsson Effect.
The Silk Road Model ("SRM") (8)
3.1 Area in "SRM"
The simulation model, "SRM," for a feasibility study
of interconnection in the Eastern area of the Eurasian
Continent for around the year 2020, is composed of
seven power systems in a heavy demand area in central
Russia, a hydropower supply area on the River Yenisei,
a solar power supply area in the Gobi desert, a fossil
fuel power supply area in Siberia, a large demand
and supply area in central China, Korea and Japan
Another simulation case includes hydraulic power,
planned to be developed in Chinsha Chiang on the River
Yanze in China, instead of solar power in the Gobi
Desert. Fig. 1 shows "SRM with solar power in the
Gobi Desert. The capital costs are figured to the
simulation for hydraulic power plants in central Russia
and natural gas combustion power plants in Siberia
as well as hydraulic power plants along the Chinsha
Chiang as they will be newly installed. Solar power
plants in the Gobi Desert, of which maximum available
capacity is 50 GW, however, have already been installed,
so, the capital cost is not counted. Instead M&O (maintenance
& operation) costs are figured into this simulation.
3.2 Simulation Data
Since the purpose of this simulation is to evaluate
possible interconnections from an economic point of
view, technical data regarding converter stations
and transmission lines are actual and up to date,
while the other data are generated from reasonable
assumptions.
Simulation data include: Seasonal daily load curves
(every four-hours) for each system. Combination of
generation plants in each power system. Transmission
line resistance.
Data for the objective function includes: Production
unit cost for each kind of generation plant in each
power plant in each power system. Equipment and installation
cost for a converter station per MW, annum. Equipment
and installation cost for a transmission lines per
MW, per Km, per annum.
Production unit cost is introduced based on the
future energy source cost estimation, transportation
cost and so on. Equipment and installation costs are
estimated at a little less than current costs due
to expected technology development.
3.3 Objective Function
Objective function is as follows; Total Annual Cost
(V)= Constraints: Generation Plant Capacity Converter
Station Capacity Transmission Line Capacity Demand
Supply Balance where
In "SRM," the value (V) of objective function, that
is the sum of cost for power generation, transmission
and converter stations, shall be minimized under the
constraints of transmission loss, supply-demand balance,
generation capacity, transmission capacity, and converter
capacity. A hypothetical node (H) is set on a branch
in the system to evaluate the feasibility of the interconnection.
If the transmission capacity between the two nodes,
or two power systems, is positive under the minimum
value condition of V, then interconnection is feasible.
The simulation should be conducted to minimize the
objective function under the constraints given by
the parametric data of peak load, load curve, generation
capacity, generation cost, load factor of hydropower
station, converter station capacity and transmission
loss.
In the model, transmission loss is a very important
factor in such long transmissions. As its characteristics
are a quadratic expression of transmission power,
it is introduced as piece-wise linear to the model.
3.4 Simulation Cases
Following scenarios are simulated for a feasibility
study by "SRM." As a base case (Case-0), we evaluate
the total annual cost without interconnections. Two
types of base case simulations have been conducted,
one case (Case-1-*) being with solar power in the
Gobi Desert and the other case (Case-2-*) being with
hydraulic power along the Chinsha Chiang. Simulation
cases are summarized in Table 1.
In two types of simulations, besides base cases
(Case 1-1, 2-1), cases with double annual cost for
a transmission line between Korea and Japan (Case
1-2, Case 2-2) have been simulated. "Double annual
cost" includes a submarine power cable. Another case
includes a converter station installed at the east
end of the Russian UHV transmission network (point
in Fig. 1) (Case 1-3). This leads to shorter power
transmission lines between the Russia System and China
System than the base case (Case 1-1).
3.5 Simulation Results
Simulation results for total annual costs and optimal
installation capacities of converter stations and
transmission lines are shown in Table 2. In this table,
total annual costs are calculated in relation to the
Case-0 (no interconnection).
For Case 1-1 as well as Case 2-1 (base cases), interconnections,
excluding Russia System, are economically advantageous.
The total cost in each of these cases is lower than
that of Case-0by 1.7% in Case 1-1 and by 1.0% in Case
2-1. Two new bulk generating areas, solar power in
the Gobi Desert (Case 1-1) and hydraulic power along
the Chinsha Chiang (Case 2-1), and natural gas combustion
power in Siberia, are interconnected as well in these
cases. China System generates more power than its
demand, while Korea and generate less than their demands.
Since all systems pay or take surplus production costs
from each another, it is possible for all to benefit
even when equipment and installation costs are paid.
The simulation results, conducted with reasonable
equipment and installation costs, show the economical
feasibility of interconnections between China, Korea,
and Japan. It is quite notable that economic feasibility
was shown even when annual costs for the transmission
line between Korea and Japan included as double.
It will be interesting that, in both cases (Case
1-2, Case 2-2), interconnection capacity is lower
than that of the base cases. And natural gas combustion
power in Siberia is economically attractive.
If the Russian UHV transmission network reaches
the east end and interconnection there is available,
in Case 1-3, interconnections with Russia System will
bring much more economic merit. In this case, the
direction of electric power flow along interconnections
changes, depending on the demand of each system for
the day.
Fig. 2 shows an example of power flow profiles during
summer period in Case 1-1.
4. Conclusion
Japanese power systems engineers have long dreamed
of encircling the Japan Seas with transmission lines
and cables. This dream is now popular among people
throughout Asia. Then, why has not the dream been
made into reality?
So far as available technology is concerned, there
are almost no difficulties to overcome, as noted in
the second chapter of this paper.
How about money? In the 16th Congress of the World
Energy Council, Mr. A. A. Churchill, an American energy
consultant, displayed the English sense of humor in
his presentation entitled "Money is not the problem:
It is the answer." (9) If I understand
him correctly, it means that people would like to
invest in any project, as long as it is commercially
attractive. (9)
Then, there are political and diplomatic issues.
Today, as Dr. Kwon (4) tells us,
the political climate in East Asia is becoming more
conductive to the successful promotion of power systems
interconnection beyond national borders. But should
we be so optimistic?
As we have witnessed regional disputes break out
all over the world after the end of the Cold War,
we must ensure a sound basis for international cooperation
among the countries concerned. This is not only a
political issue but, much more importantly, a social
and cultural problem to be solved not necessarily
by politicians but by people in all walks of life.
This is the reason why I put much more importance
on education and grass root activity. It takes time
for people from different societies and cultures to
achieve mutual understanding necessary for successful
international cooperation. (10)
References
- World Energy Council 16th Congress:
"Technical Program," Oct. 1995
- Prutichai Chonglertvanichkul;
"Planning of ASEAN Grid," Panel on Project Development
at the International Symposium on "Sustainable Energy
Development in Asia," May 1996 Hong Kong.
- Zheng Meite; "A Study on the
Interconnection of Power System in China," Panel
on Interconnection of Power Grids, August 1996 ICEE'96,
Beijing China
- S-H Kwon et al: "Consideration
on Interconnecting Electric Utility Companies in
Far East Asia," Panel on Interconnection of Power
Grids, August 1996 ICEE'96, Beijing China
- N.I. Voropai, G.V. Shutov; "The
Conditions and Possible Trends in Formation of Interstate
Interconnection in East Asia," Panel on Interconnection
of Power Grids, August 1996 ICEE'96, Beijing China
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of Power Grids-The Japanese Point of View-" ICEE'96,
Beijing China
- K. Sakamoto, et. Al. "Development
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AC/DC Converter" IEEE SM 1997 held in Berlin
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Study on Interstate Interconnections of Electric
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HVDC Technology" Sino-Japanese Symposium on Sustainable
Development and Advanced Science and Technology,
Lanzhou Aug. 1997
- Churchill, Anthony A.; "Money
is not the Problem: It is the Answer," 16th World
Energy Congress, Tokyo Oct. 1995
- Arakawa, Fumio; "Power System
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Global Society--," IEEE/PES-WM, Feb. 1991
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