공동주택에 적용한 계통연계형
태양광발전시스템의 보호방식에 관한 연구 A Study on the Protection Method of the Grid-Connected
Photovoltaic Power Generation System Applied to Apartments
高麗大學敎工學大學院
電氣工學科
李根燁
2011年
A Study on the Protection Method of the
Grid-Connected Photovoltaic Power
Generation System Applied to Apartments
BY GeunYub Lee
Dept. of Electrical Eng.
The Graduate School
Korea University
(Supervised by Prof. Gilsoo Jang, Ph.D)
Abstract
Global environment problems have emerged rapidly throughout
international society since the 1990s. Diverse global environment
problems are being raised including global warming, ozone depletion,
waste contamination, acid rain, desertification, marine pollution,
extinction of species, and radioactive contamination. The root cause
of these phenomena is energy consumption. Moreover, around a
fourth of the total energy consumption is consumed by buildings. In
Korea, buildings consume around 25% of the total energy
consumption, and residential buildings consume around 75% of
energy consumed by buildings and energy consumption by
residential buildings is expected to keep growing along with the rise
of economic level. Taking this issue seriously, the Korean
government has been supporting investments in research and
facilities for energy saving and alternative energy technologies since
the 1980s as an effort to secure future energy sources, to solve
global environment problems, and to attain sustainable economic
growth. Recently, facilities using new and renewable energies are
being spread and expanded and people are recognizing particularly
the importance of technologies for photovoltaic power generation as
an infinite energy source.
Considering the current situation of Korea highly dependent on
fossil energy, the application of photovoltaic power generation to
apartment buildings is desirable not only for the growth of national
economy and the stable security of alternative energy resources but
also for the conservation of global environment. Nevertheless, there
have not been many studies for developing technologies to connect
photovoltaic systems to electric companies. It is urgently required
to increase stable electric power supply of enhanced reliability and
to develop system connection technologies. The installation of
photovoltaic systems is steadily increasing as evidenced by the onemillion
green home construction project under the government’s
active support. If photovoltaic facilities are installed on the slanting
roofs of apartment buildings and connected to existing distribution
systems, they may have an adverse effect on quality, stability and
reliability of electric power and, most of all, may disrupt the
protective coordination of systems. The connection of photovoltaic
systems to distribution systems means a new change in the
conventional concept of electric power system. Thus, this study
aimed to analyze the quality of electric power required and
expected problems when photovoltaic facilities are connected to
distribution systems, to look for solutions for the problems, and
ultimately to enhance the performance, stability and reliability of
photovoltaic systems and establish technological conditions to be
satisfied for connection to distribution systems.
First, this study examined how to prevent islanding detection
caused by power failure in existing distribution systems during the
connected operation of photovoltaic facilities and existing
distribution systems and to minimize the loss of human life and
properties caused by such accidents.
Second, this study analyzed the capacity of photovoltaic facilities
connectable to low‐voltage distribution systems based on voltage
regulation as a part of research on the capacity of photovoltaic
systems connected to existing distribution systems.
Third, with regard to the ground system of photovoltaic facilities,
this study demonstrated the need of a new evaluation method
suitable for DC systems apart from existing AC ones.
There will be unexpected problems raised along with the spread of
system‐connected photovoltaic facilities. Thus we expect active
research to find solutions for problems resulting from connection
between photovoltaic facilities and distribution systems and to
hasten the stable supply of electric power to consumers through
photovoltaic facilities using solar energy.
