Jiecheng Zhao

Dr. Jiecheng Zhao

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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10 June 2016 in IEEE Transactions on Smart Grid
Verified
Journal Article
Open access
WYWenxuan Yao
Wenxuan Yao
YLYong Liu
Yong Liu
DZDao Zhou
Dao Zhou
PZPan Zhuohong
Pan Zhuohong
MTMicah J. Till
Micah J. Till
YLYilu Liu
Yilu Liu
With the aid of global positioning system (GPS), synchronized measurement devices (SMDs) are increasingly deployed across power systems to monitor the status of electric grids by providing accurate measurement data along with unified time stamps. Unfortunately, GPS receivers tend to lose signal lock when certain uncontrollable and unpredictable factors arise. In order to investigate the presence of GPS signal loss (GSL) issues on measurement devices, analysis is performed on historical data from both phasor data concentrators and FNET/GridEye servers. Meanwhile, the impact of GSL on field measurement accuracy has not been previously explored in depth. Through analysis and experimental tests, this paper discovers angle drift caused by GSL, which consequently leads to the total vector error exceeding the IEEE standard C37.118.1-2011. Furthermore, a compensation method is proposed to rectify the angle drift and laboratory experiments demonstrate that the proposed method does effectively reduce angle drift and mitigate the impact of GSL in SMDs.

23 May 2017 in IEEE Access
Verified
Journal Article
Open access
WYWenxuan Yao
Wenxuan Yao
JZJiecheng Zhao
Jiecheng Zhao
MTMicah J. Till
Micah J. Till
Shutang YouShutang You
Shutang You
YLYong Liu
Yong Liu
YLYilu Liu
Yilu Liu
The distribution-level electric network frequency (ENF) extracted from an electric power signal is a promising forensic tool for multimedia recording authentication. Local characteristics in ENF signals recorded in different locations act as environmental signatures, which can be potentially used as a fingerprint for location identification. In this paper, a reference database is established for distribution-level ENF using FNET/GridEye system. An ENF identification method that combines a wavelet-based signature extraction and feedforward artificial neural network-based machine learning is presented to identify the location of unsourced ENF signals without relying on the availability of concurrent signals. Experiments are performed to validate the effectiveness of the proposed method using ambient frequency measurements at multiple geographic scales. Identification accuracy is presented, and the factors that affect identification performance are discussed.

9 February 2017 in IEEE Access
Verified
Journal Article
Open access
YLYong Liu
Yong Liu
Shutang YouShutang You
Shutang You
WYWenxuan Yao
Wenxuan Yao
YCYi Cui
Yi Cui
LWLing Wu
Ling Wu
YLYilu Liu
Yilu Liu
The wide area monitoring system (WAMS) is considered a pivotal component of future electric power grids. As a pilot WAMS that has been operated for more than a decade, the frequency monitoring network FNET/GridEye makes use of hundreds of global positioning system-synchronized phasor measurement sensors to capture the increasingly complicated grid behaviors across the interconnected power systems. In this paper, the FNET/GridEye system is overviewed and its operation experiences in electric power grid wide area monitoring are presented. Particularly, the implementation of a number of data analytics applications will be discussed in details. FNET/GridEye lays a firm foundation for the later WAMS operation in the electric power industry.

19 June 2017 in IET Generation, Transmission & Distribution
Verified
Journal Article
Open access
PDF file
Shutang YouShutang You
Shutang You
YLYong Liu
Yong Liu
MTMicah J. Till
Micah J. Till
JZJiecheng Zhao
Jiecheng Zhao
WYWenxuan Yao
Wenxuan Yao
YLYilu Liu
Yilu Liu
This study presents a method to locate power system disturbances using wide‐area synchropahsor measurements. The merits of the proposed method include robustness and ease of visualisation. In addition, the proposed method facilitates the calculation of electromechanical wave propagation speed distribution. Examples of locating the disturbance and generating the propagation speed distribution are demonstrated using the FNET/GridEye system, a distribution‐level wide‐area measurement system. Without losing generality, the proposed method can be implemented in any other wide‐area measurement system.

8 February 2016 in IEEE Transactions on Power Delivery
Verified
Journal Article
Open access
Lingwei ZhanLingwei Zhan
Lingwei Zhan
YLYong Liu
Yong Liu
WYWenxuan Yao
Wenxuan Yao
JZJiecheng Zhao
Jiecheng Zhao
Yilu LiuYilu Liu
Yilu Liu
Global positioning system (GPS)-based phasor measurement units (PMUs) are increasingly deployed in the power system in order to monitor the grid status in real time. Nevertheless, GPS receivers inside PMUs tend to lose signal lock when certain uncontrollable and unpredictable factors arise. To address this issue, the chip-scale atomic clock is proposed to be used as a backup solution for time synchronization in this paper. It is the first time ever reporting the utilization of CSAC in the electric power grid. Test results show that CSAC can work as a reliable and accurate backup for GPS timing.

2 June 2016 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
WYWenxuan Yao
Wenxuan Yao
Lingwei ZhanLingwei Zhan
Lingwei Zhan
YLYong Liu
Yong Liu
MTMicah J. Till
Micah J. Till
JZJiecheng Zhao
Jiecheng Zhao
YLYilu Liu
Yilu Liu
This paper focuses on a novel method for successive approximation register analog to digital converter control in synchronized phasor measurement units (PMUs). To compensate for the sampling time error caused by the division remainder between the desirable sampling rate and the oscillator frequency, a variable sampling interval control method is presented by interlacing two integers under a proposed criterion. The frequency of the onboard oscillator is monitored in real-time using the pulse per second (PPS) timing reference from global positioning system. The sampling control is adaptively adjusted each second according to the latest estimated oscillator frequency. The “saw tooth” in phasor angle error and DC offset and spikes in frequency error can be effectively eliminated by applying the proposed method. The simulation and experiment results validate the effectiveness and accuracy of the proposed method, which is believed to be able to greatly improve the performance of PPS-disciplined synchronous sampling methods in PMUs.