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Global power systems are transiting from conventional fossil fuel energy to renewable energies due to their environmental benefits. The increasing penetration of renewable energies presents challenges for power system operation. The efficiency and sufficiency of responsive reserves have become increasingly important for power systems with a high proportion of renewable energies. The Fast Frequency Reserve (FFR), especially the Wide-area Monitoring System (WAMS)-based FFR, is a promising and effective solution to secure and enhance the stability of power systems. However, cyber security has become a new challenge for the WAMS-based FFR system. Cyber attacks on the FFR control system may threaten the safety of power system operation due to the rapid power controllability requirement of FFR. To address this problem, a time-frequency based cyber security defense framework is proposed to detect the cyber spoofing of synchrophasor data in WAMS-based FFR control systems. This paper first introduces the Continuous Wavelet Transforms (CWTs) to decompose spoofing signals. Then, the Dual-frequency Scale Convolutional Neural Networks (DSCNN) is proposed to identify the time-frequency domains matrix from two frequency scales. Integrating CWTs and DSCNN, an identification framework called CWTs-DSCNN is further proposed to detect the spoofing attacks in the WAMS-based FFR system. Multiple experiments using the actual data from FNET/GridEye are performed to verify the effectiveness of the framework in securing WAMS-based FFR systems.
Wei Qiu; Kaiqi Sun; Wenxuan Yao; Shutang You; He Yin; Xiaoyang Ma; Yilu Liu. Time-frequency based cyber security defense of wide-area control system for fast frequency reserve. International Journal of Electrical Power & Energy Systems 2021, 132, 107151 .
AMA StyleWei Qiu, Kaiqi Sun, Wenxuan Yao, Shutang You, He Yin, Xiaoyang Ma, Yilu Liu. Time-frequency based cyber security defense of wide-area control system for fast frequency reserve. International Journal of Electrical Power & Energy Systems. 2021; 132 ():107151.
Chicago/Turabian StyleWei Qiu; Kaiqi Sun; Wenxuan Yao; Shutang You; He Yin; Xiaoyang Ma; Yilu Liu. 2021. "Time-frequency based cyber security defense of wide-area control system for fast frequency reserve." International Journal of Electrical Power & Energy Systems 132, no. : 107151.
Due to the independent controllability and fast power regulation capability, the High Voltage Direct Current (HVDC) system could be a prospective technology to provide multiple ancillary services to the system besides conventional bulk power transmission. However, with the increase of False Data Injection Attacks (FDIAs) on PMU data, the HVDC system could have the wrong response once the collected data that the HVDC system relied on is attacked, thus threatening the system operating security. How to ensure the security of the PMU-based HVDC ancillary service control become an urgent issue. To mitigate the risk, this paper proposed an HVDC attack-defense control based on the FDIAs detection method. Firstly, the Squeeze-Excitation based Double Convolutional Neural Networks (SE-DCNN) is proposed to realize fast identification of the attacking frequency type based on the time and frequency domain signals. The duration time of FDIAs is detected by the local outlier factor. Then, utilizing the results from SE-DCNN, HVDC ancillary service control framework is reorganized and an HVDC attack defense control is proposed for suppressing the potential influence of various types of FDIAs on the HVDC system ancillary service. Different experiments results demonstrate that the proposed methods have the ability to significantly mitigate the frequency deviation and oscillation under the FDIA.
Kaiqi Sun; Wei Qiu; Wenxuan Yao; Shutang You; He Yin; Yilu Liu. Frequency Injection based HVDC Attack-defense Control via Squeeze-Excitation Double CNN. IEEE Transactions on Power Systems 2021, PP, 1 -1.
AMA StyleKaiqi Sun, Wei Qiu, Wenxuan Yao, Shutang You, He Yin, Yilu Liu. Frequency Injection based HVDC Attack-defense Control via Squeeze-Excitation Double CNN. IEEE Transactions on Power Systems. 2021; PP (99):1-1.
Chicago/Turabian StyleKaiqi Sun; Wei Qiu; Wenxuan Yao; Shutang You; He Yin; Yilu Liu. 2021. "Frequency Injection based HVDC Attack-defense Control via Squeeze-Excitation Double CNN." IEEE Transactions on Power Systems PP, no. 99: 1-1.
Urban power grids are facing many operational and expansion challenges to meet further demand growth and increased reliability requirements. Advanced transmission technologies have been considered by the electric utilities to effectively increase the utilization of existing infrastructure and operational flexibility. The focus of this paper is on VSC-HVDC technologies for urban power grid enhancement and modernization. First, a potential technical scheme is proposed for converting an existing AC circuit to DC operation, which could boost the power transfer capability of the critical transmission corridor and increase network operational flexibility. Second, this paper proposes three operation modes for the VSC-HVDC interties in urban power grids corresponding to normal, emergency and island operating conditions, respectively. An integrated, adaptive emergency control strategy (AEC) is proposed that can enable adaptive power flow responses of the VSC-HVDC intertie under varying system operating conditions and critical contingencies. The flexibility and effectiveness of the proposed operational principles of urban VSC-HVDC intertie and the corresponding control strategies are verified in PSCAD/EMTDC using a realistic urban power grid in China.
Kaiqi Sun; HuangQing Xiao; Jiuping Pan; Yilu Liu. VSC-HVDC Interties for Urban Power Grid Enhancement. IEEE Transactions on Power Systems 2021, 36, 4745 -4753.
AMA StyleKaiqi Sun, HuangQing Xiao, Jiuping Pan, Yilu Liu. VSC-HVDC Interties for Urban Power Grid Enhancement. IEEE Transactions on Power Systems. 2021; 36 (5):4745-4753.
Chicago/Turabian StyleKaiqi Sun; HuangQing Xiao; Jiuping Pan; Yilu Liu. 2021. "VSC-HVDC Interties for Urban Power Grid Enhancement." IEEE Transactions on Power Systems 36, no. 5: 4745-4753.
The High Voltage Direct Current (HVDC) intertie has been applied to provide ancillary-services for AC grids, utilizing the real-time feedback from Phasor Measurement Units (PMUs). However, PMU data communication is vulnerable to False Data Injection Attacks (FDIA) due to protocol defects, thus the HVDC ancillary control and system stability will be threatened. To address this issue, this paper proposes a novel HVDC control strategy based on a Hybrid Data-driven (HDD) methodology. The HDD methodology is first proposed to detect the types and duration time of multiple frequency attacks. Specifically, the Hilbert Huang Transform (HHT) is used to decompose the frequency data, using variational mode decomposition (VMD) instead of the traditional empirical mode decomposition, to extract data features. Second, a Multi-kernel Support Vector Machine (MSVM) is proposed to classify the attacked data based on the designed distinctive features from HHT. Meanwhile, the attacking duration time is decided using an unsupervised technique. Third, an HDD-based HVDC ancillary control strategy is established to eliminate the effect of FDIAs on the HVDC frequency response. Comprehensive experiments of HDD-based HVDC ancillary controls under different FDIAs suggest that the proposed HDD could fast and accurately classify the FDIAs, and the HDD-based HVDC ancillary control strategy could significantly suppress the impact of the FDIAs.
Wei Qiu; Kaiqi Sun; Wenxuan Yao; Weikang Wang; Qiu Tang; Yilu Liu. Hybrid Data-Driven Based HVdc Ancillary Control for Multiple Frequency Data Attacks. IEEE Transactions on Industrial Informatics 2021, 17, 8035 -8045.
AMA StyleWei Qiu, Kaiqi Sun, Wenxuan Yao, Weikang Wang, Qiu Tang, Yilu Liu. Hybrid Data-Driven Based HVdc Ancillary Control for Multiple Frequency Data Attacks. IEEE Transactions on Industrial Informatics. 2021; 17 (12):8035-8045.
Chicago/Turabian StyleWei Qiu; Kaiqi Sun; Wenxuan Yao; Weikang Wang; Qiu Tang; Yilu Liu. 2021. "Hybrid Data-Driven Based HVdc Ancillary Control for Multiple Frequency Data Attacks." IEEE Transactions on Industrial Informatics 17, no. 12: 8035-8045.
Hybrid HVDC system, which consists of the advantages of line commutated converter (LCC) and voltage source converter (VSC), is an emerging power transmission system. This paper presents a review of four LCC-VSC hybrid HVDC topologies. The first topology is the pole-hybrid HVDC system, in which the LCC and VSC form the positive- and negative-pole respectively. The second one is the terminal-hybrid HVDC system; in this topology one terminal adopts LCC and the other terminal adopts VSC. The series converter-hybrid HVDC system is the third topology wherein each terminal is formed by LCC and VSC in series. The fourth hybrid topology under consideration is a parallel converter-hybrid HVDC system with LCC and VSC connected in parallel in each terminal. The main contribution of this paper is a comprehensive analysis and comparison of the four mentioned hybrid topologies in terms of PQ operating zone, power flow reversal method, and DC fault ride-through strategy.
HuangQing Xiao; Kaiqi Sun; Jiuping Pan; Yujun Li; Yilu Liu. Review of hybrid HVDC systems combining line communicated converter and voltage source converter. International Journal of Electrical Power & Energy Systems 2021, 129, 106713 .
AMA StyleHuangQing Xiao, Kaiqi Sun, Jiuping Pan, Yujun Li, Yilu Liu. Review of hybrid HVDC systems combining line communicated converter and voltage source converter. International Journal of Electrical Power & Energy Systems. 2021; 129 ():106713.
Chicago/Turabian StyleHuangQing Xiao; Kaiqi Sun; Jiuping Pan; Yujun Li; Yilu Liu. 2021. "Review of hybrid HVDC systems combining line communicated converter and voltage source converter." International Journal of Electrical Power & Energy Systems 129, no. : 106713.
With the increasing penetration level of renewable power, the power systems’ inertias are decreasing. To ensure that the frequency is above the threshold of the under frequency load shedding, one effective way is to share the spinning reserves among asynchronous AC grids through HVDC systems. In this paper, a coordinated frequency regulation scheme that enables spinning reserves sharing is proposed for such hybrid AC/DC grids. This scheme is a communication-free method that consists of the droop control, the inertia emulation control and the frequency safety control. The combined response of the three controls can increase not only the frequency nadir but also the settled frequency of the disturbed grid. In addition, the hysteresis comparators and the power injection limits are adopted in the frequency regulation scheme to reduce the coupling effect among AC grids. Thus, under small and harmless disturbance, the frequency regulation scheme will be inactive; the disturbance in strong AC grids would not affect the weak AC systems. The frequency regulation scheme coordinates well with the automatic generation control of the grids. The feasibility and effectiveness of the proposed frequency regulation scheme are verified through simulation studies.
HuangQing Xiao; Kaiqi Sun; Jiuping Pan; Liang Xiao; Chun Gan; Yilu Liu. Coordinated frequency regulation among asynchronous AC grids with an MTDC system. International Journal of Electrical Power & Energy Systems 2020, 126, 106604 .
AMA StyleHuangQing Xiao, Kaiqi Sun, Jiuping Pan, Liang Xiao, Chun Gan, Yilu Liu. Coordinated frequency regulation among asynchronous AC grids with an MTDC system. International Journal of Electrical Power & Energy Systems. 2020; 126 ():106604.
Chicago/Turabian StyleHuangQing Xiao; Kaiqi Sun; Jiuping Pan; Liang Xiao; Chun Gan; Yilu Liu. 2020. "Coordinated frequency regulation among asynchronous AC grids with an MTDC system." International Journal of Electrical Power & Energy Systems 126, no. : 106604.
Due to the heavy stress on environmental deterioration and the excessive consumption of fossil resources, the transition of global energy from fossil fuel energy to clean energy has significantly accelerated in recent years. The power industry and policymakers in almost all countries are focusing on clean energy development. Thanks to progressive clean energy policies, significant progress in clean energy integration and greenhouse gas reduction has been achieved around the world. However, due to the differences in economic structures, clean energy distributions, and development models, clean energy policy scope, focus, and coverage vary between different countries, states, and utilities. This paper aims at providing a policy review for readers to easily obtain clean energy policy information on various clean energies in the U.S. and some other countries. Firstly, this paper reviews and compares some countries’ clean energy policies on electricity. Then, taking the U.S. as an example, this paper introduces the clean energy policies of some representative states and utilities in the U.S in perspectives of renewable energies, electric vehicles, and energy storage.
Kaiqi Sun; HuangQing Xiao; Shengyuan Liu; Shutang You; Fan Yang; Yuqing Dong; Weikang Wang; Yilu Liu. A Review of Clean Electricity Policies—From Countries to Utilities. Sustainability 2020, 12, 7946 .
AMA StyleKaiqi Sun, HuangQing Xiao, Shengyuan Liu, Shutang You, Fan Yang, Yuqing Dong, Weikang Wang, Yilu Liu. A Review of Clean Electricity Policies—From Countries to Utilities. Sustainability. 2020; 12 (19):7946.
Chicago/Turabian StyleKaiqi Sun; HuangQing Xiao; Shengyuan Liu; Shutang You; Fan Yang; Yuqing Dong; Weikang Wang; Yilu Liu. 2020. "A Review of Clean Electricity Policies—From Countries to Utilities." Sustainability 12, no. 19: 7946.
The increasing deployment of phasor measurement units and the advances of their reporting rates are challenging the present data centers in terms of storing and analyzing large-volume data. Under power system disturbance conditions, it is difficult to retain critical information while compressing the synchrophasor data effectively. This article combines the cross entropy and the singular value decomposition, proposing a novel model to compress the synchrophasor data to an extremely small size yet keep superior accuracy. The proposed model is extensively tested and compared with the state-of-the-art algorithms using the simulated and the FNET/GridEye field-collected data. The result indicates that the proposed algorithm has superior performance in compressing the data while retaining critical information under disturbance conditions.
Weikang Wang; Chang Chen; Wenxuan Yao; Kaiqi Sun; Wei Qiu; Yilu Liu. Synchrophasor Data Compression Under Disturbance Conditions via Cross-Entropy-Based Singular Value Decomposition. IEEE Transactions on Industrial Informatics 2020, 17, 2716 -2726.
AMA StyleWeikang Wang, Chang Chen, Wenxuan Yao, Kaiqi Sun, Wei Qiu, Yilu Liu. Synchrophasor Data Compression Under Disturbance Conditions via Cross-Entropy-Based Singular Value Decomposition. IEEE Transactions on Industrial Informatics. 2020; 17 (4):2716-2726.
Chicago/Turabian StyleWeikang Wang; Chang Chen; Wenxuan Yao; Kaiqi Sun; Wei Qiu; Yilu Liu. 2020. "Synchrophasor Data Compression Under Disturbance Conditions via Cross-Entropy-Based Singular Value Decomposition." IEEE Transactions on Industrial Informatics 17, no. 4: 2716-2726.
Cross-seam high voltage DC (HVDC) transmission in the United States can provide an efficient and flexible bulk power delivery highway between the interconnections. Recent studies have shown significant economic benefits of cross-seam HVDC transmission systems by taking the advantages of load diversity, frequency response, renewable energy diversity, and energy arbitrage in the different interconnections. This paper introduces a station-hybrid system scheme for cross-seam interconnections. The proposed station-hybrid system combines the advantages of line commutated converter (LCC) and voltage source converter (VSC) technologies, thus enabling reliable and flexible bidirectional power flows across the interconnections. Control strategies of the station-hybrid system are investigated with a focus on power flow reversal control under normal operation conditions and grid support control under emergency conditions. The feasibility and effectiveness of the proposed station-hybrid system and corresponding control strategies are verified by simulations in PSCAD/EMTDC.
Kaiqi Sun; HuangQing Xiao; Jiuping Pan; Yilu Liu. A Station-Hybrid HVDC System Structure and Control Strategies for Cross-Seam Power Transmission. IEEE Transactions on Power Systems 2020, 36, 379 -388.
AMA StyleKaiqi Sun, HuangQing Xiao, Jiuping Pan, Yilu Liu. A Station-Hybrid HVDC System Structure and Control Strategies for Cross-Seam Power Transmission. IEEE Transactions on Power Systems. 2020; 36 (1):379-388.
Chicago/Turabian StyleKaiqi Sun; HuangQing Xiao; Jiuping Pan; Yilu Liu. 2020. "A Station-Hybrid HVDC System Structure and Control Strategies for Cross-Seam Power Transmission." IEEE Transactions on Power Systems 36, no. 1: 379-388.
Because of the steady increase of wind and solar capacity installations in recent years, the goal of the Paris Agreement is expected to be reached. However, due to the intermittent characteristics of renewable generation, challenges are presented for the power grid to operate reliably and economically under the high uncertainty of wind and solar power productions. Sufficient responsive reserves must be available for the power grid to maintain the balance between the supply and demand. To be fair to the market participants, the renewable generation companies should pay for the received grid ancillary services. In this paper, an optimal combined operation scheme is proposed for pumped storage hydro and hybrid wind-photovoltaic complementary power generation system interconnected by a Voltage Source Converter-based multi-terminal HVDC system. The optimal combined operation scheme has two real-time control functions. The pumped storage hydro control function enables automatic dispatch of the pumped storage hydro to effectively suppress or compensate for the output deviations of wind and solar generation from the forecasted production; and the output control function is able to distribute the non-compensated production surplus or deficit to different ac systems based on the market regulating service prices. A Case study is provided to demonstrate the improved power generation profile and reduced revenue losses of the pumped storage hydro and hybrid wind-photovoltaic complementary power generation system.
Kaiqi Sun; Ke-Jun Li; Jiuping Pan; Yong Liu; Yilu Liu. An optimal combined operation scheme for pumped storage and hybrid wind-photovoltaic complementary power generation system. Applied Energy 2019, 242, 1155 -1163.
AMA StyleKaiqi Sun, Ke-Jun Li, Jiuping Pan, Yong Liu, Yilu Liu. An optimal combined operation scheme for pumped storage and hybrid wind-photovoltaic complementary power generation system. Applied Energy. 2019; 242 ():1155-1163.
Chicago/Turabian StyleKaiqi Sun; Ke-Jun Li; Jiuping Pan; Yong Liu; Yilu Liu. 2019. "An optimal combined operation scheme for pumped storage and hybrid wind-photovoltaic complementary power generation system." Applied Energy 242, no. : 1155-1163.
Kaiqi Sun; Ke-Jun Li; Wei-Jen Lee; Zhuo-Di Wang; Weiyu Bao; Zhijie Liu; Meiyan Wang. VSC-MTDC System Integrating Offshore Wind Farms Based Optimal Distribution Method for Financial Improvement on Wind Producers. IEEE Transactions on Industry Applications 2019, 55, 2232 -2240.
AMA StyleKaiqi Sun, Ke-Jun Li, Wei-Jen Lee, Zhuo-Di Wang, Weiyu Bao, Zhijie Liu, Meiyan Wang. VSC-MTDC System Integrating Offshore Wind Farms Based Optimal Distribution Method for Financial Improvement on Wind Producers. IEEE Transactions on Industry Applications. 2019; 55 (3):2232-2240.
Chicago/Turabian StyleKaiqi Sun; Ke-Jun Li; Wei-Jen Lee; Zhuo-Di Wang; Weiyu Bao; Zhijie Liu; Meiyan Wang. 2019. "VSC-MTDC System Integrating Offshore Wind Farms Based Optimal Distribution Method for Financial Improvement on Wind Producers." IEEE Transactions on Industry Applications 55, no. 3: 2232-2240.
Zhijie Liu; Ke-Jun Li; Jinyu Wang; Zahid Javid; Meiyan Wang; Kaiqi Sun. Research on Capacitance Selection for Modular Multi-Level Converter. IEEE Transactions on Power Electronics 2018, 34, 8417 -8434.
AMA StyleZhijie Liu, Ke-Jun Li, Jinyu Wang, Zahid Javid, Meiyan Wang, Kaiqi Sun. Research on Capacitance Selection for Modular Multi-Level Converter. IEEE Transactions on Power Electronics. 2018; 34 (9):8417-8434.
Chicago/Turabian StyleZhijie Liu; Ke-Jun Li; Jinyu Wang; Zahid Javid; Meiyan Wang; Kaiqi Sun. 2018. "Research on Capacitance Selection for Modular Multi-Level Converter." IEEE Transactions on Power Electronics 34, no. 9: 8417-8434.
With the increasing penetration of renewable energies, the seamless integration and related energy management problems present challenges to the traditional power grid. Voltage source converter based multi-terminal HVDC (VSC-MTDC) has been regarded as a prospective emerging technology for the above mentioned issues. With its flexible control characteristics, it is expected that VSC-MTDC systems will play important role in the future power grid. Furthermore, a multi-voltage level VSC-MTDC systems will have the potential to enhance the flexibility and redundancy of the power system. This paper presents control algorithms for a multi-voltage-level DC network to improve the utilization rate of renewable energies and mitigate the coordinated and interconnected problems of distributed renewable energies and urban power load. The operating of auto-power-balancing mode and the power cooperation mode and their corresponding control strategies are analyzed in this paper. For the auto-power-balancing mode, the centralized DC power control is proposed to mitigate the disturbance caused by power fluctuation. For the power cooperation mode, the unbalanced power redistribution control is proposed to eliminate the unbalanced power when the master station encounters problems. The simulation in PSCAD/EMTDC for a twelve VSC-MTDC system demonstrates the effectiveness of the proposed operation modes and corresponding control strategies.
Kaiqi Sun; Ke-Jun Li; Wei-Jen Lee; Zhuo-Di Wang; Zhijie Liu; Meiyan Wang; Zahid Javid. Operation and control for multi-voltage-level dc network to improve the utilization rate of renewable energies. 2017 IEEE Industry Applications Society Annual Meeting 2017, 1 -8.
AMA StyleKaiqi Sun, Ke-Jun Li, Wei-Jen Lee, Zhuo-Di Wang, Zhijie Liu, Meiyan Wang, Zahid Javid. Operation and control for multi-voltage-level dc network to improve the utilization rate of renewable energies. 2017 IEEE Industry Applications Society Annual Meeting. 2017; ():1-8.
Chicago/Turabian StyleKaiqi Sun; Ke-Jun Li; Wei-Jen Lee; Zhuo-Di Wang; Zhijie Liu; Meiyan Wang; Zahid Javid. 2017. "Operation and control for multi-voltage-level dc network to improve the utilization rate of renewable energies." 2017 IEEE Industry Applications Society Annual Meeting , no. : 1-8.
With the development of urban economy and the growing integration of renewable energy, there are increasingly challenges on urban power grid. Due to the transmission stress and short-circuit current limitation, the traditional urban power grid cannot satisfy the new requirements. Multi-voltage-level DC grid(MDCG) is an alternative approach to urban power grid upgrade. This paper presents a MDCG topology, which can be used in future urban power grid. Three operation modes of urban MDCG is proposed: auto operation mode, power-limited operation mode and stand-alone operation mode. The auto operation mode is the normal one for urban MDCG. The power-limited operation mode is designed for keeping the capability to support urban high voltage ac transmission grid in emergencies. The stand-alone operation mode is used to keep stability in case the dc-dc converter system occurs outage. The combination control of three operation modes is put forward to enhance the reliability of urban MDCG in various operating conditions. The simulation results show that the proposed operation modes and combination control are effectiveness and have good performance.
Kaiqi Sun; Ke-Jun Li; Zhuo-Di Wang; Huadong Sun; Mingqiang Wang; Zhijie Liu; Meiyan Wang. Operation Modes and Combination Control for Urban Multivoltage-Level DC Grid. IEEE Transactions on Power Delivery 2017, 33, 360 -370.
AMA StyleKaiqi Sun, Ke-Jun Li, Zhuo-Di Wang, Huadong Sun, Mingqiang Wang, Zhijie Liu, Meiyan Wang. Operation Modes and Combination Control for Urban Multivoltage-Level DC Grid. IEEE Transactions on Power Delivery. 2017; 33 (1):360-370.
Chicago/Turabian StyleKaiqi Sun; Ke-Jun Li; Zhuo-Di Wang; Huadong Sun; Mingqiang Wang; Zhijie Liu; Meiyan Wang. 2017. "Operation Modes and Combination Control for Urban Multivoltage-Level DC Grid." IEEE Transactions on Power Delivery 33, no. 1: 360-370.
Mid-long term load forecasting is the prerequisite of power system planning. This paper first introduces the sub-area partitioning of power grid in Nanjing core area. Then the influences of social-economic factors to mid-long term load are studied by two ways, which are correlation analysis method and multiple linear regression analysis method. Based on the analysis results of the two methods, a grey MGM (1, N) load forecasting model is constructed. Furthermore, by forecasting the maximal load of different districts, the multiple linear regression Grey MGM (1, N) model and ordinary multiple linear regression models are compared. The results show that the method proposed in this paper has higher accuracy and wider adaptability. Finally, this paper analyzes the load developing tendency in different districts of the city and proposes corresponding suggestions.
Haiwei Wu; Dawei Su; Xuesong Huo; Shuang Hu; Zhuodi Wang; Kaiqi Sun. The research of mid-long forecasting based on MGM (1, N) model with multiple linear regression analysis in Nanjing core area. 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) 2016, 38 -42.
AMA StyleHaiwei Wu, Dawei Su, Xuesong Huo, Shuang Hu, Zhuodi Wang, Kaiqi Sun. The research of mid-long forecasting based on MGM (1, N) model with multiple linear regression analysis in Nanjing core area. 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC). 2016; ():38-42.
Chicago/Turabian StyleHaiwei Wu; Dawei Su; Xuesong Huo; Shuang Hu; Zhuodi Wang; Kaiqi Sun. 2016. "The research of mid-long forecasting based on MGM (1, N) model with multiple linear regression analysis in Nanjing core area." 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) , no. : 38-42.
This paper presents an alternative approach to voltage source converter based multi-terminal direct current (VSC-MTDC) performance analysis. The approach is to build a small-scale physical model of the VSC-MTDC transmission system, with renewable energies and integration devices. The platform is capable of investigating the operating performance, renewable energy integration, and control strategies of VSC-MTDC. Furthermore, it can be used to investigate the influences of renewable energy's random variation on VSC-MTDC system. Such complex phenomenon is very difficult to be investigated using digital simulation methods. Finally, simulations under normal operation and under the situation of wind power variation are carried out, and the results prove the feasibility and stability of the designed dynamic simulator.
Zhijie Liu; Ke-Jun Li; Xinhan Meng; Wei-Jen Lee; Zhuo-Di Wang; Kaiqi Sun. Dynamic simulator for multi-terminal direct current transmission system. 2016 IEEE Industry Applications Society Annual Meeting 2016, 1 -9.
AMA StyleZhijie Liu, Ke-Jun Li, Xinhan Meng, Wei-Jen Lee, Zhuo-Di Wang, Kaiqi Sun. Dynamic simulator for multi-terminal direct current transmission system. 2016 IEEE Industry Applications Society Annual Meeting. 2016; ():1-9.
Chicago/Turabian StyleZhijie Liu; Ke-Jun Li; Xinhan Meng; Wei-Jen Lee; Zhuo-Di Wang; Kaiqi Sun. 2016. "Dynamic simulator for multi-terminal direct current transmission system." 2016 IEEE Industry Applications Society Annual Meeting , no. : 1-9.
With the increasing demand of electricity, the development of urban power grid has drawn a lot of attention in China. In order to focus on the analysis of urban power grid, the remaining part of the large-scale power grid used to be reduced. The accuracy of the equivalence is key to urban power grid research. In this paper, a multi-step dynamic equivalent method based on district-dividing is proposed. Based on the electrical distance, voltage level and geographic location, the external system is divided into outer layer, inner layer and buffer subsystem. Each district is separately reduced by different methods. The proposed technique is illustrated by a real large-scale power grid in the south of China.
Xiaoyan Yu; Ke-Jun Li; Mingqiang Wang; Zhuo-Di Wang; Kaiqi Sun; Jie Lou. A multi-step dynamic equivalent method for urban power grid based on district-dividing. 2016 IEEE Industry Applications Society Annual Meeting 2016, 1 -8.
AMA StyleXiaoyan Yu, Ke-Jun Li, Mingqiang Wang, Zhuo-Di Wang, Kaiqi Sun, Jie Lou. A multi-step dynamic equivalent method for urban power grid based on district-dividing. 2016 IEEE Industry Applications Society Annual Meeting. 2016; ():1-8.
Chicago/Turabian StyleXiaoyan Yu; Ke-Jun Li; Mingqiang Wang; Zhuo-Di Wang; Kaiqi Sun; Jie Lou. 2016. "A multi-step dynamic equivalent method for urban power grid based on district-dividing." 2016 IEEE Industry Applications Society Annual Meeting , no. : 1-8.
Increasing accuracy of predicting the transformer top-oil temperature (TOT) and winding hot-spot temperature (HST) is essential to improving the utilization of transformer. This paper presents a combination model to improve TOT prediction accuracy. The main feature of this model is its combination of both model-driven model's and data-driven model's advantages. First, an available thermal circuit is utilized to predict the TOT roughly; second, a data-driven model based on support vector machine (SVM) is established to approximate the thermal circuit prediction error; and finally, the SVM is utilized to correct prediction results of the thermal circuit. The proposed model is tested on a 200-kVA distribution transformer and the obtained results are compared with existing thermal circuit model and data-driven model. The analysis result demonstrates the validity and accuracy of the combination model.
Xiaowu Qi; Kejun Li; Jingshan Wang; Kaiqi Sun. Transformer top-oil temperature combination modeling based on thermal circuit and support vector machine. 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) 2016, 1933 -1937.
AMA StyleXiaowu Qi, Kejun Li, Jingshan Wang, Kaiqi Sun. Transformer top-oil temperature combination modeling based on thermal circuit and support vector machine. 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC). 2016; ():1933-1937.
Chicago/Turabian StyleXiaowu Qi; Kejun Li; Jingshan Wang; Kaiqi Sun. 2016. "Transformer top-oil temperature combination modeling based on thermal circuit and support vector machine." 2016 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) , no. : 1933-1937.
Grid-connected control method and simulations of the micro-grid are presented in the paper. The typical configuration of the micro-grid is presented. In order to ameliorate the effect of power quality during the grid- connected process, the power flow in the micro-grid is analyzed based on the characteristic of frequency and active power, and the time when the difference value of the voltage between the main grid and the micro-grid become zero is chosen as the best chance to connect. In the grid-connected mode, P/Q control is adopted. By the simulation tool Matlab/Simulink, different grid-connected processes are simulated and compared. The frequency and active power fluctuations are analyzed. The results indicate that the control method is effective in dominating the micro-grid during the grid-connected mode, and the choice of the best chance to connect has a great effect on the power quality in the micro-grid.
He-Jin Liu; Ke-Jun Li; Hong-Xia Gao; Ying Sun; Kai-Qi Sun; Wei-Jen Lee. Control and simulation of grid-connected micro-grid. 2012 IEEE Power and Energy Society General Meeting 2012, 1 -6.
AMA StyleHe-Jin Liu, Ke-Jun Li, Hong-Xia Gao, Ying Sun, Kai-Qi Sun, Wei-Jen Lee. Control and simulation of grid-connected micro-grid. 2012 IEEE Power and Energy Society General Meeting. 2012; ():1-6.
Chicago/Turabian StyleHe-Jin Liu; Ke-Jun Li; Hong-Xia Gao; Ying Sun; Kai-Qi Sun; Wei-Jen Lee. 2012. "Control and simulation of grid-connected micro-grid." 2012 IEEE Power and Energy Society General Meeting , no. : 1-6.