Yu Liu

Dr. Yu Liu

School of Electrical Engineering, Southeast University, Nanjing 210018, China
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 February 2021 in Protection and Control of Modern Power Systems
Verified
Journal Article
Open access
PDF file
SLSai Liu
Sai Liu
CZCheng Zhou
Cheng Zhou
HGHaomin Guo
Haomin Guo
QSQingxin Shi
Qingxin Shi
TSTiancheng E. Song
Tiancheng E. Song
YLYu Liu
Yu Liu
As a key component of an integrated energy system (IES), energy storage can effectively alleviate the problem of the times between energy production and consumption. Exploiting the benefits of energy storage can improve the competitiveness of multi-energy systems. This paper proposes a method for day-ahead operation optimization of a building-level integrated energy system (BIES) considering additional potential benefits of energy storage. Based on the characteristics of peak-shaving and valley-filling of energy storage, and further consideration of the changes in the system’s load and real-time electricity price, a model of additional potential benefits of energy storage is developed. Aiming at the lowest total operating cost, a bi-level optimal operational model for day-ahead operation of BIES is developed. A case analysis of different dispatch strategies verifies that the addition of the proposed battery scheduling strategy improves economic operation. The results demonstrate that the model can exploit energy storage’s potential, further optimize the power output of BIES and reduce the economic cost.

23 August 2022 in IEEE Transactions on Transportation Electrification
Verified
Journal Article
Closed access
CWChuanshen Wu
Chuanshen Wu
HHHaiteng Han
Haiteng Han
SGShan Gao
Shan Gao
YLYu Liu
Yu Liu
Because of the rapid development of electric vehicles (EVs), the energy management of multimicrogrid (MMG) systems has attracted considerable research attention. The objective of this study is to coordinate scheduling performance for MMG systems under large-scale EV operations. To address the problem that the calculation time increases exponentially with the scale of EVs, a clustering algorithm was proposed to speed up the solving efficiency of the coordinated scheduling of MMG systems. To address the problem of the departure and arrival times of clustering EV crossover among various MGs, the proposed clustering algorithm set the boundary of the parking period of clustering EVs by maximizing their controllable time in various MGs. The coordinated scheduling strategy of MMG systems was executed considering the charging cost of EVs, the optimization of transmission power curves, and the absorption of renewable energy. The simulation results revealed that by fully utilizing the mobile energy storage characteristics of EVs, the performance of MMG systems can be maximized. Meanwhile, the computing efficiency of coordinated scheduling can be considerably improved in the case of large-scale EVs integrated into MMG systems by using the proposed clustering algorithm.

7 January 2022 in IEEE Access
Verified
Journal Article
Open access
YZYANG ZEXIN
YANG ZEXIN
XHXueliang Huang
Xueliang Huang
TGTian Gao
Tian Gao
YLYu Liu
Yu Liu
SGShan Gao
Shan Gao
With the rapid increase of electric vehicles (EVs), the uncoordinated charging of large-scale EVs will inevitably form a new peak of power consumption, which will put forward new requirements for the adjustment of EV charging behavior and the power supply capacity of the distribution network. However, upgrading the infrastructure of the distribution network is very expensive, so it is of great value to research on how to realize the optimal integration of EVs without infrastructure upgrading. In this paper, an intelligent grouping method is proposed considering the coupling relationship among EV travel information, battery status and other characteristics, and a charging/discharging priority model is established based on the contribution index of charging process. Finally, a smart real-time energy management strategy is formed in order to maximize the penetration level of EVs under current conditions. With the strategy proposed, the maximum penetration level of EVs is increased from 20% to 60% in the simulation. The strategy has good adaptability to the gradually growth of the base load, which can effectively delay infrastructure upgrading of the distribution network and reduce the overall operation cost of the station. It could furtherly provide a reference for the operation and upgrading of the parking lot charging station.

22 December 2016 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
YLYu Liu
Yu Liu
GGGuangchao Geng
Guangchao Geng
SGShan Gao
Shan Gao
WXWilsun Xu
Wilsun Xu
Energy use monitoring techniques are useful to home and facility owners, enabling them to save energy and reduce costs. The monitoring methods published so far are focused on detecting individual appliances and determining their respective energy consumption. This paper proposes a method for estimating the energy use of a group of appliances with similar electrical characteristics and operation patterns. The proposed method consists of two steps. The first step is to determine the probability that a given electrical event is caused by a member of the appliance group of interest. The second step analytically estimates the mean value and standard deviation of the total energy use of the appliance group based on the combination of Bernoulli distributions. Case studies using both simulations and field measurements have shown that the proposed method is able to accurately detect power and energy for a given group of appliances. It fills an important gap in non-intrusive energy use monitoring research for homes and facilities.

19 May 2021 in IEEE Access
Verified
Journal Article
Open access
SGShan Gao
Shan Gao
TSTiancheng E. Song
Tiancheng E. Song
SLSai Liu
Sai Liu
CZCheng Zhou
Cheng Zhou
CXChenkai Xu
Chenkai Xu
SWSicheng Wang
Sicheng Wang
The multi-region integrated energy system (MRIES) is one promising option for exploiting the complementarity potentials between power system, thermal system and loads, as well as improving flexibility and economic competitiveness. However, the optimal planning has remained challenging since it involves multiple forms of energies with the nature of coupling. A mixed integer linear programming (MILP) model is proposed for joint optimization of MRIES planning and operation, which considers the flexible load's demand response (DR). It is realized by combining the multi-region heating network IES coupling model with the flexible cooling-heating-electric load DR model. The results show that the proposed model can assist planners to comprehensively analyze and evaluate the impacts of multiple factors on planning, and to determine the optimal planning configuration and operation strategy.

1 March 2023 in Electric Power Systems Research
Verified
Journal Article
Closed access
YZYANG ZEXIN
YANG ZEXIN
TGTian Gao
Tian Gao
YLYu Liu
Yu Liu
XHXueliang Huang
Xueliang Huang
SGShan Gao
Shan Gao
HDHongen Ding
Hongen Ding