Optimal control and management of a large-scale battery energy storage system to mitigate fluctuation and intermittence of renewable generations
Optimal control and management of a large-scale battery energy storage system to mitigate fluctuation and intermittence of renewable generations
Xiangjun LI 0
Liangzhong YAO 0
Dong HUI 0
0 State Key Laboratory of Control and Operation of Renewable Energy and Storage Systems, China Electric Power Research Institute , Beijing 100192 , China
Battery energy storage system (BESS) is one of the effective technologies to deal with power fluctuation and intermittence resulting from grid integration of large renewable generations. In this paper, the system configuration of a China's national renewable generation demonstration project combining a large-scale BESS with wind farm and photovoltaic (PV) power station, all coupled to a power transmission system, is introduced, and the key technologies including optimal control and management as well as operational status of this BESS are presented. Additionally, the technical benefits of such a large-scale BESS in dealing with power fluctuation and intermittence issues resulting from grid connection of large-scale renewable generation, and for improvement of operation characteristics of transmission grid, are discussed with relevant case studies.
Battery energy storage systems; Renewable generations; Power fluctuation; Battery energy management system; Power control
1 Introduction
Renewable energy power generation has become an
important part for China’s power supply. By June 2016, the
grid’s wind-power capacity had been 124 GW and the
photovoltaic (PV) capacity had been 61 GW. The rapid
development and implementation of renewable power
generation pose great challenges to the operation, control,
and security of the Chinese power grid. Large-scale battery
energy storage system (BESS) can effectively compensate
the power fluctuations resulting from the grid connections
of wind and PV generations which are random and
intermittent in nature, and improve the grid friendliness for
wind and PV generation grid integration.
Large-scale BESS can participate in the operation as
either the power supply or the load when needed. Unlike
traditional power generation systems, BESS can act as a
rapid-response active and reactive power injection or
absorption device [1–8]. The BESS can be used to smooth
the power fluctuations of PV or wind power stations
[9–12]. Based on the existing researches and
implementations of large-scale BESS worldwide, countries such as the
United States, Germany and Japan, have carried out more
than 200 demonstration projects. For example, redox flow
and sodium sulfur battery is one of the cutting edge
technologies for renewable energy power generation
applications in Japan [13–15]. There are also more applications of
lithium-ion BESS in the United States, such as in the fields
of renewable energy generations, distributed generations,
micro grids, etc. The American Xtreme Power, Duke
Energy, Altairnano, and AES Energy storage companies,
for example, have conducted researches on energy storage
technologies [16–18]. At present, existing applications of
large-scale lithium, sodium-sulfur or redox flow battery
have reached to tens of megawatts (MW) in power rating.
However, they are generally used only for wind energy
storage or solar energy storage respectively. Although the
MW power level of BESS is generally high, the MWh
capacity level is relatively low. For example, the BESS of
Japan Hokkaido wind farm incorporates a vanadium redox
flow BESS with the power capacity 4 MW/6 MWh and is
mainly for smoothing the wind power output fluctuations
[18–20]. The Japan Aomori Six Village energy storage
power station utilizes a sodium sulfur BESS with the power
capacity 34 MW, mainly for smoothing the wind power
fluctuations [18, 21]. The Texas wind farm storage power
station uses an advanced lead-acid battery (36 MW/
9 MWh), principally for frequency regulation, energy
transfer and peak load shaving [18, 22]. The West Virginia
Elkins wind farm energy storage power station incorporates
a lithium-ion battery (32 MW/8 MWh) which is for
frequency regulation and output climbing control [18, 23].
In China, there are a number of large-scale BESS
demonstration projects currently underway. For example, in
Zhangbei, a large-scale BESS, which includes a 14 MW/63 MWh
lithium-ion BESS and a 2 MW/8 MWh vanadium redox flow
BESS, has been put into operation (flow BESS is still in the site
commissioning stage). It is part of a national wind, PV, storage
and transmission demonstration project. The purpose of this
project is to smooth the wind and PV power fluctuations and
trace the scheduled power outputs to grid. Further, Guodian
Longyuan Woniushi wind farm energy storage power station,
using total vanadium flow batteries (5 MW/10 MWh), is
adopted mainly to resolve wind-curtailment and brownout
issues arising at the Woniushi wind farm. The BESS of
Southern Power Grid Shenzhen Baoqing adopted the
lithiumion battery (planned capacity is 10 MW and completed
capacity is 4 MW/16 MWh) to (...truncated)