Energy and Power E ngineering, 2013, 5, 171-176
doi:10.4236/epe.2013.54B033 Published Online July 2013 (http://www.scirp . org/journal/epe)
Copyright © 2013 SciR es. EPE
Research on Microgrid and its Application in China
Xing Wu, Xiaogang Yin, Quan Wei, Yifan Jia, Jing Wang
Research and Development Cent er, Xi'an Hi gh Volt age Apparatus R esearch Institut e Co., Ltd, X i'an, China
Received February, 2013
This paper presents the state of the art research and application of microgrid in China, and then introduces the major
concerns for the development of microgrid. The research related to microgrid in China arose around 2004, focused on
the connection of distributed energy resources (DERs) to grid and its influence on distribution network, and then fol-
lowed the micro grid co ncept of Consortium for Electric Reliability Technology Solutions (CERTS). However, the mi-
cro gri d in China has taken a more active path with the development of DER and the encouragement of t he d eve lo p ment
of smart grid and resource and energy needing. Now, nearly every province in China has typical researches and applica-
tions of microgrid. Besides, there are already two major patterns in the development of microgrid, the institute-domi-
nating research and the enterprise-dominating application. Research institutions like Tianjin University, Hefei Univer-
sity of Technology, Xian J iaoto ng University, Ins titute of Electrical Engineering (Chinese Academy of Sciences), etc.,
are leading the research on microgrid. The companies like State Grid Corporation of China (SGCC), China Southern
Power Grid (CSPG), etc., have accomplished several demonstration projects of microgrid, and give a further boost to its
application. At the end of the paper, according to the present situation of the development of microgrid in China, the
facing problems a nd the way to d e a l with it are put forward.
Keywords: Microgrid; Distri buted Energy Resources; Research; Demonstration
1. Introduction
Since the entrance of 21st century, developing clean
energy and ensuring the safety of energy have become
the ke ywords in the energy industry. It is a common goal
to build cleaner and more reliable power systems. In or-
der to overcome the negative impact of distributed ener-
gy resources (DERs) on power system, and maximize the
potential of DERs, the microgrid concept was proposed
by Lassst er et al at the Univer sit y of Wisco nsinMadison
(UWM). The microgrid can be operated as a single sys-
tem with DERs and loads [1-3]. The Consortium for
Electric Reliability Technology Solutions (CERTS) then
presented the white paper on integration of DERs. The
CERTS microgrid concept assumes an aggregation of
loads and DERs operating as a single system providing
both power and heat [4]. The proof of the concept was
accomplished at UWM [5], the microgrid test bed was
then constructed at Dolan Technology Centre [6].
Typ ical CERTS microgrid is illustrated in F igure 1 [4].
It consists o f micr o sourc es, p o wer and volta ge contro ller,
point of common coupling (PCC), circuit breaker, sepa-
ration device and so on. The CERTS microgrid concept
is the most popular microgrid concept around the world.
The CERTS microgrid concept is an important reference
for the researches and the appl ic at ions in China.
2. Background of Microgrid in China
In China, the microgrid develops with the boom of DER
technology, especially the new energy (renewable energy)
technology. The Chinese government attaches great im-
portance to the develop ment o f distributed energy gener-
ation based on new ener gy. It is clearly stated that China
will promote the low-cost large-scale development and
utilization of renewable energy in the National Outline
for Medium and Long Term Science & Technology
Figure 1. C ERTS micro grid arch itecture.
Copyright © 2013 SciR es. EPE
Development (2006-2020). The National Outl i ne fo r 12th
Five-Year Science and Technology Development also
put forwards a vision for the development of the new
energy technology. The latest released Special Planning
of 12th Five-Year Plan on Smart Grid Major Science &
Technology Industrialization Projects emphasizes the
importance to break through the technology of large-
scale intermittent new energy and its storage. Chinese
government issued Renewable Energy Law of the
People's Republic of China, and medium & long-term
Renewable Energy Development Plan to further accele-
rate the development of DER. With the support of the
national policies mentioned above, the amount of in-
vestment in renewable energy in China has reached
$51billion in 2011, the total installed capacity of wind
power has exceeded 62 GW, and newly installed capacity
of solar power has increased to 2.2 GW. The develop-
ment of DER technology based on renewable energy in
China has been an inevita ble trend.
Meanwhile, the research and application of micro-grid
in China also continues to heat up. The microgrid in
China started by following others, however, it takes a
more active way with the support of national policies on
DER. Within less than one decade, there are already two
developing patterns of microgrid in China, the insti-
tute-dominating research and enterprise-dominating ap-
plication. With financial support of National Basic Re-
search Program (973 Program), National High Technol-
ogy Development Program (863 Program), National
Natural Science Foundation of China (NSFC), etc., the
research of microgrid in China includes various aspects
of the microgrid technology. At the same time, the
state-owned enterprises and the private enterprises in-
crease their investment in the application of DER and
microgrid, and nearly every province in China has al-
ready had typical DER and microgrid applications.
3. Research on Microgrid
The research of microgrid in China began around 2004.
It is carried out in accordance with the CERTS microgrid
conc ept , foc usin g on DE Rs i nter co nnecti ng with t he bul k
power system and their influence on the power network.
Now, the research in China covered the key technical
issues of microgrid, including: (1) the planning and de-
sign of microgrid (including DER)[7-12]; (2)operating
characteristics of micro sources [13-15]; (3) microgrid
operation and its energy management (including energy
storage technology)[16-19]; (4) interconnection of mi-
crogrid to the bulk power system[20-22]; (5)island mode
of microgrid [23-25]; (6) protection of microgrid [26-28],
and so on.
Research institutions like Tianjin University, Hefei
University of Technology, Xi’an Jiaotong University,
Institute of Electrical Engineering (Chinese Academy of
Sciences), etc., are leading the research on microgrid.
Scholars in Tianjin University started their research
from the perspective of planning and design of power
system. With the financial support of 973 Program and
863 Program, they carried out research on the planning
and design of the microgrid and DERs, the operation,
control and protection of the microgrid and the distribu-
tion network with DERs. They have built a small micro-
grid experimental system and an integrated microgrid
system [29]. The small microgrid experimental system is
illustrated in Fig ure 2. T his is single -phase 230 V, 50 Hz
system. It is composed of energy storage system, photo-
voltaic (PV ) simulator, wind po wer simulator and r elated
control systems. The microgrid central controller (MCC)
is used for the energy management. The system can be
operated at two steady-state operation modes (intercon-
nection and island), and two transient-state operation
modes (transition between interconnection mode and
island mode).
Hefei Universit y of Technology developed a microgrid
system with multi-energy generators through collabora-
tive research with the University of New Brunswick,
Canada [30, 31]. They carried out research on the opti-
mization of the design, control and scheduling strategies
of the microgrid. The microgrid structure is shown Fig-
ure 3. T he syst em consis ts of a 1 0 kW si ngle-phase and a
30 kVA three-phase PV generators, two 30 kW three-
phase wind generation si mul ator s , 5 kW fuel cell, 300 Ah
battery bank, 1800F ultra-capacitor bank and two sets of
15kW co nventional ge nerators used to simulate the small
hydro and small fossil generators, various loads (resistors,
capacitor, inductors, AC and DC motors and other elec-
tronic loads). This microgrid has two-layer hierarchical
control system, the local controllers and the central con-
troller. An energy management system that conforms to
the IEC61970 standards was developed.
The research on microgrid in Xi'an Jiaot ong University
started with the application of power electronics tech-
nology. With the financial support of 863 program and
Figure 2 . The s mall microgri d ex perimental sy stem in Ti an-
jin University.
Copyright © 2013 SciR es. EPE
Figure 3. The microgrid system in Hefei University of
NSFC, they have done extensive and intensive research
on the circuit topology and control strategy of power
electronics devices in the microgrid, and have developed
a fast simula tion platform for microgrid based on PSCAD.
During this process, they proposed a seamless control
strategy to evaluate the platform [32], developed a dy-
nami c reactive power compensation device and its con-
trol method for microgrid [33], and proposed a method to
use virt ual impedance to improve the stabilit y of wireless
connection between multiple inverters in microgrid [34].
They also studied the topology of microgrid. The micro-
grid that they proposed consists of wind, solar, gasoline
generators, and energy storage, including battery and
super capacitor.
Institute of Electrical Engineering, Chinese Academy
of Sciences (IEECAS) is a pioneer of the research on
microgrid in China. With the fina ncial support of 863
Program and NSFC, they have done intensive research
on the basic theory, key technologies, and experimental
platform of microgrid. They also developed a series of
control and protection technologies and devices, includ-
ing a common interface for interconnection between
DER and microgrid [35], a hybrid energy storage con-
troller of super capacitor and battery [36], a small-signal
model of super capacitor energy storage to improve vol-
tage stability [37], microgrid operation control strategies
[17] and so on. Moreover, they built a microgrid test
platfor m, completed the design and commissionin g o f the
grid-connected inverter and other accessories unit, and
accomplished combine heat and power (CHP) system in
their laboratory. Meanwhile, they built several test plat-
for ms for analysis and testing of super capacitor, simula-
tion of dynamic voltage, and AC-DC-AC motor drive
system, etc. In addition, the institute has built a number
of renewable-energy-generation technology lab, includ-
ing variable speed constant frequency wind turbine con-
verter laboratory stand-alone PV, wind and solar control
laboratory, large-scale wind turbine control system la-
boratory, large-scale grid-connected PV inverter labora-
tory, power electronics laboratory, and solar thermal
power generation test bed.
4. Application of Microgri d
Smart grid is the key word in the powe r ind ustr y of Chi-
na. The implementation of smart grid requires multi-
level, robust and reliable electricity network. Microgrid
is an important part of the network. Typical Chinese en-
terprises, like SGC C and CSP G, have done a lot of work
to apply the technology of microgrid, and have built sev-
eral demonstration projects of microgrid with world-
leading le vel.
SGCC is the largest electric utilities company that
transmits and d istrib utes po we r in C hi na and i n t he wor ld .
It proposed the slogan to build a strong smart grid in
2009, and wished to complete the grid in 2020. With the
inspiration of this slogan, SGCC has completed many
demonstration projects of microgrid and DER, including
the pilot pr oject for distributed PV power ge neratio n and
microgrid operation control in Henan province, the pilot
projects for control of microgrid in Hangzhou city and
Xi'an city, and the microgrid projects in the rural area of
north China.
Zhongxin Tianjin Eco-city microgrid system is the
first microgrid system in the constructions for smart grid
of SGCC. It realized the communication between micro-
grid systems and distribution automation system, and
data exchange between microgrid and intelligent build-
ings for the first time. The microgrid system includes a
380V/30kW PV system, 5 kW wind power, 25 kW × 2 h
energy storage, and monitoring and pr otection devices. It
can achieve autonomous control protection and man-
agement, and can be operated at interconnection mode
and island mode.
With the support of 863 Program, SGCC led the re-
search on development of key technologies in microgrid
with DERs, and developed an integrated platform for
control/protection of microgrid. They built an off-grid
microgrid demonstration project in Nanlu Island and a
grid-connected microgrid demonstration project in Luxi
Island. The microgrid in Nanlu Island consists of 10 ×
100-kW wind turbines, 545 kW PV power generation
system, 1600 kW diese l p o we r ge ner a tio n s ystem, 2 0 kW
ocean current power generation systems, and energy sto-
rage system, with integration of electrical vehicle
charging station, smart meters and other advanced smart-
grid technologies. Luxi Island microgrid is composed of
2 × 780 kW wind turbines, 300 kW PV power generation
systems and energy storage system. It can achieve flexi-
ble transition between grid-connected mode and off-grid
Copyright © 2013 SciR es. EPE
To r esolve the key i ssues i n the large -scale application
of DERs, Zhangbei wind/solar/ba tte r y demonstration
project is built by SGCC. It is a key project of National
Science and Technology Support Program and the Na-
tional “Golden Sun” Program, and is the first pilot
project of SGCC for the strong smart grid. The total in-
vestment of this project exceeds ¥12 billion. The entire
project contains 500 MW wind power, 100 MW PV and
110 MW b a tte r ies, and a 220 kV intelligent substation.
The project is an aggregation of all the advanced tech-
nologies in power design, wind power, PV, energy sto-
rage, control and protection. The first stage o f this proje c t
had been completed by the end of 2011. The investment
of this stage is ¥3.3 billion, including 100 MW wind
power, 40 MW PV and 20MW battery. The framework
of the system is sho wn in Fig ure 4. T he wind tur bine s i n
this project include the doubly-fed wind turbines, di-
rect-drive wind turbines and the vertical-axis wind tur-
bines. The PV cells include the monocrystalline silicon
cell, the polycrystalline silicon cell, a morp hous thin-film
solar cell and dye-sensi tized solar cell. The solar trackers
include the fixed tracker, horizontal single-axis tracker,
tilted single a xis tracker and d ual-axis tracker. The batte-
ries contain lithium iron phosphate batteries, vanadium
redox batteries and sodium-sulphur batteries. The proj ect
will become the worlds largest demonstration project
with the highest level of intelligent operation of wind
power, PV, energy storage.
CSPG pursues the goa l to build an intelligent, efficient,
reliable and green smart grid. They keep improving the
stability and reliability of power system, the utilization
efficiency of resources. They have made great efforts to
inves tigate t he DER and microgri d tec hnology.
CSPG built a typical microgrid system with combined
cooling, heating and power (CCHP) in Foshan city,
Guangdong province, providing electricity and cooling
for three office buildings. This project be longs to the 863
ProgramStud y on i ntegration and demonstration of dis-
tributed CCHP technology with MW- class gas turbine
and “Study on key technology and demonstratio n of in-
terconnect ion of microgrid with MW-class distributed
CCHP system. It focuses on the optimization of design,
operation of microgrid, and the i mpact on the distribution
network. The demonstration project started operating in
February, 2010. The str uctur e is sho wn i n Figure 5 [38].
The experiment building, part of the loads in dispatch
building, and the miroturbines were connected with the
low voltage bus LM1, the rest of the loads in dispatch
building were connected to LM2. Bus LM3 will provide
electricity for the loads in multifuncti onal building. The
CCHP system consists of the microturbine set (three
200kW microturbines) and LiBr double-effect absorption
chiller. This project studies protection, control and su-
pervision of power quality in microgrid system with
Figure 4. The framework of Zhangbei wind/solar/battery
demonstration project.
Figure 5 . CSPG microgrid syste m i n Foshan city .
CCHP, provides the foundation for the application of
CSPG paid special attention to the energy storage
technology. Baoqing, the MW-class energy-storage power
station was built in Shenzhen, and came into service in
September, 2011. The power station can output 110 kV
electricit y for industry, the total energy-storage capacity
exceeds 12 MWh. Compare with Zhangbei demonstra-
tion project focusing on the combination of new energy
and energy storage, Baoqing power station pays much
attention to lo ad shifting, r egulation of voltage/frequency,
and microgrid isla nding.
5. Microgrid at Xi’an High Voltage
Apparatus Research Institute Co., Ltd
Xi’an High Voltage Apparatus Research Institute Co.,
Ltd (XIHARI) has the National Engineering Laboratory
for High Voltage Electric, National Energ y Research and
Development (Testing) Centre for Power Transmission
and Distribution Equipment, and National Quality Su-
pervision & Inspection Test Centre for high voltage ap-
paratus, insulator and surge Arrestor, power capacitor,
Copyright © 2013 SciR es. EPE
and intelligent p ower equipme nt. It is responsible for the
research and development of power equipment, power
test and establishment of national standards. XIHARI
plays a very important role in smart grid, new energy
(renewable energy). Microgrid technology is a nother ke y
technology that XIHARI is developing. Figure 6 shows
the framework of on-going mi cr o gri d pr oj e ct in XI HARI .
This project focuses on economic operation and energy
management o p timization of microgrid. The microgrid
consists of 20 kW PV, 2 kW wind power, 20 kWh bat-
tery, and d iesel generator. Several interfaces are prepared
for electrical vehicle charging system and static var ge-
nerator (SVG).
6. Prospects of the Microgrid Technology
As an optimized integration of DER, microgrid has been
the fo c us ar o und the wor ld . Micr o gr id p la ys a n i mportant
role in the strong smart grid in China. Microgrid has
many advantages; however, there are several problems
that need to be solved before the large scale application
in China.
Lack of national standards and specific policies of mi-
crogrid is the priority. There are standards about DER,
for example, the IEEE P1547 standard. The standards of
DER in China are establishing and amending, but spe-
cific standards and national policies of microgrid about
the interconnection, design and planning, construction
and operation, and manufacturing are still absent.
Second, the microgrid technology is not yet mature.
Compare with traditional integrated power generation,
the development cost and the operation cost are very high.
The microgrid technology needs improving.
Third, the microgrid needs legalizing, and establishing
new economic relation with bulk power system. Accord-
ing to the present electricity law of China, the gird-co n-
nection microgrid is illegal if it outputs electricity.
Meanwhile, the output electricity of private microgrid
Figure 6 . Microgri d in XIHARI.
conflicts with the operation of current electric power
system. New economic relation should be established to
ensure mutual interest.
7. Conclusions
The microgrid concept has been proposed and applied for
years to solve the interconnection issues of DER to the
bulk p ower s ystem abr oad. I n China, microgri d develops
with the boost of DER (with renewable energy). Though
microgrid becomes more and more popular in China, the
foundation of microgrid technology is weak, it needs
time to realise commercial operation, especially with the
support of national policies, laws and regulations. The
development of microgrid technology in China is bound
to be a long process.
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