Deng W.,Hunan University |
Li X.,Hunan University |
Liu Z.,Foshan Power Supply Bureau |
Yan Y.,Hunan University |
And 2 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012
The output power of intermittent distributed generation (DG) such as distributed wind generation (DWG) and photovoltaic (PV) is random and the load is uncertain. Aiming at the investment expenses of intermittent DG and compensation capacitor, income of electricity sale, reduction of system power loss, voltage quality and emission reductions, the optimal configuration models of intermittent DG and capacitor were built using chance constrained programming method. Genetic algorithm was chosen for the optimal solution. The simulation results show that the comprehensively optimized allocation model has improved expected value of node voltage and the probability within normal range. The comprehensive optimization of economic benefit, environ-mental benefit and voltage quality were achieved, and the rationality and availability of the proposed model is verified. © 2012 Chin. Soc. for Elec. Eng.
Guo H.,Inner Mongolia University |
Guo H.,Northeast Dianli University |
Fang J.,Northeast Dianli University |
Wang Z.,Foshan Power Supply Bureau
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2014
The method for suppressing the speckle noise in sonar images based on an improved P-M model is proposed. In the improved P-M model, if the gradient magnitude of an image is within the wavelet threshold range, the improved diffusion function is the weighted summation of the classical diffusion function and exponential function. The improved P-M model was applied to suppress the speckle noise in the sonar image from a small object lying on sea bed. The result is compared with those using the classical P-M model, median filter and Wiener filter. In terms of suppressing speckle noise, the improved P-M model is better than the classical model, and has an advantage over the median filter and Wiener filter. In terms of preserving image edges, the improved model is better than the classical model, median filter and Wiener filter. The test experiments show that after suppressing the speckle noise using the improved P-M model, the peak signal to noise ratio of the image is above 26 dB and the edge preserving degree is above 98%.
Peng X.,Guangdong Electric Power Research Institute |
Zhan Q.,Foshan Power Supply Bureau |
Zhou H.,Guangdong Power Grid Corporation
Dianwang Jishu/Power System Technology | Year: 2012
In recent years the land supply for power construction projects is decreased increasingly and it makes the planner of UHV/EHV transmission line construction inclined to adopt the structure of multi-circuit transmission lines on the same tower, therefore as the result the proportion of simultaneous lightning outage of multi-circuit transmission lines on the same tower evidently raises, thus the secure operation of power grid is affected. The peculiarity of simultaneous lightning outage occurred in multi-circuit transmission lines on the same tower is presented and the influences of key factors on lightning outage are analyzed, besides, the recovery analysis on electromagnetic transient of typical simultaneous lightning outage fault is performed. Results of recovery analysis show that the main reason leading to simultaneous lightning outage of multi-circuit transmission lines on the same tower is the flashback of lightning, however successive shielding failures lead to simultaneous lightning outage of multi-circuit transmission lines as well. It is emphasized that special attentions should be paid to the prevention of simultaneous lightning outage occurred in 110 kV and 220 kV double circuit transmission lines on the same tower, and it is pointed out that the power frequency voltage and the phase sequence arrangement of transmission lines on the same tower greatly influence the lightning outage caused by flashback; the simultaneous lightning outages often occur in the same phase of multi-circuit transmission lines; and the flashover is prone to occur on the upper cross arm insulator that is closer to the struck point.
Ni L.,Foshan Power Supply Bureau |
Luo J.,Huazhong University of Science and Technology |
Wang S.,Huazhong University of Science and Technology
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2011
This paper improves the ACE model and controller of conventional AGC system to suppress the frequency fluctuation caused by wind power disturbances. The strong randomness and intermittence of wind forces result in the random fluctuation of wind power outputs, which will have an adverse effect on the frequency control of power system. In this paper, a new controlled variable is introduced into the ACE model of AGC system, and fuzzy-PI strategy is used to regulate PI control parameters of the controller adaptively according to the range of frequency offset. The simulation results of a two-area electrical interconnected power system show that the improved AGC system developed in this study can effectively suppress frequency fluctuation caused by wind power disturbance.
Ye L.,South China University of Technology |
Ye L.,Foshan Power Supply Bureau
Proceedings of the 5th IEEE International Conference on Electric Utility Deregulation, Restructuring and Power Technologies, DRPT 2015 | Year: 2015
Aiming at solving network planning problems brought by multi-stage and multi-objection, in this paper, a multi-objective optimization method of network planning is proposed. Considering taking economy and reliability into account, with the objective function of the minimum cost of investment, the minimum annual operating costs of the system and the minimum lack of electricity costs, a general optimized model of multi-objective electric power network planning is presented. The hierarchical optimization model and hybrid genetic-simulated annealing algorithm is used to solve the problems emerging in the process of multi-objective planning. Case proves the effectiveness and scientifically of the proposed method and algorithm. © 2015 IEEE.
Lu K.,South China University of Technology |
Zhang Y.,South China University of Technology |
Ni W.-D.,Foshan Power Supply Bureau |
Xia C.-J.,South China University of Technology
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012
According to the problem that the traditional control scheme can not meet the requirement of low-voltage ride-through for DFIG, in this paper, based on the analysis of the stator and rotor transient process, we find the causes which affect the rotor over-current and DC bus overvoltage, and propose a new feedforward compensation method based on current control, that is, in the rotor side, adding a feedforward component which can reflect the attenuation of stator flux transient; in the grid side, adding a feedforward component which can reflect the power change between the two sides of converter. Finally, a DFIG model is built under PSCAD/EMTDC platform, the validity of this new control strategy is verified by simulation results through network voltage dip.
Liu S.,Foshan Power Supply Bureau
Gaoya Dianqi/High Voltage Apparatus | Year: 2015
The pulse current detection method in GIS interval with cable outlet is analyzed, and the optimization method of the combination of UHF detection and pulse current detection is proposed. Using the pulse current method to assist the partial discharge location technology of UHF, further phase locating is performed on the three phase in one tank type GIS, the diagnostic accuracy of GIS device is improved. © 2015, Xi'an High Voltage Apparatus Research Institute. All right reserved.
Liu G.,South China University of Technology |
Ruan B.,South China University of Technology |
Zhang M.,Foshan Power Supply Bureau
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012
The transient model for overhead transmission line dynamic rating based on the thermal circuit method is proposed. The ampere-capacity of overhead lines realizes real-time calculation based on the temperature of overhead line and environment. An experiment with the step current loaded is designed, the results show that the theoretical values are bigger than the experimental data, and the maximum error is less than 1°C. The time of temperature rise is related to the thermal resistance. Another experiment with the constant current loaded 24 hours is designed for proving the feasibility of dynamic rating on overhead lines outdoors. The maximum allowed current of real-time is calculated by the transient model of the thermal circuit method. The relationship between line temperature and environment conditions is analyzed. ©2012 State Grid Electric Power Research Institute Press.
Zhu B.-T.,Foshan Power Supply Bureau |
Cheng Z.-H.,Foshan Power Supply Bureau |
Tang Z.-Q.,Foshan Power Supply Bureau |
Jiang W.,Foshan Power Supply Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013
The formulation of the IEC61850 and IEC61970 standard provides technical specifications to achieve interoperability between intelligent substation and dispatching management system. Aiming at the object model of IEC61850 and CIM model of IEC61970, this paper analyzes the model's three-tier systems, and obtains that model coordinating is the key to system interoperability. Through analyzing the differences between object model and CIM model, a model coordinating method is given. This paper uses this method to coordinate the model's categories, relations and properties, and employs adapter and interface technology to design data exchange experiment platform. Simulation results show that the coordinating method based on CIM model is effective and practical, and is able to achieve interoperability between dispatching system and intelligent substation system.
Zhao Y.,Chongqing University |
Wu X.,Foshan Power Supply Bureau |
Xie K.,Chongqing University
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2012
An approach for frequency instability risk assessment of bulk power system is proposed in this paper. Based on the dynamic frequency characteristic of spinning reserve, the model of frequency stability analysis considering under frequency load shedding is presented. Utilizing the non-sequential Monte Carlo simulation, risk indices such as instability probability, instability frequency, expected load shedding and frequency dynamic indices are calculated for probabilistic quantitative evaluation of frequency instability. The impact of spinning reserve and generators tripping on frequency instability are discussed. Moreover, the annual risk indices including or excluding uncertainty for multi-level load model are analyzed. Simulation results of IEEE-RTS79 verify that the proposed method is a powerful tool which can provide valuable reference information for identification of frequency instability risk and optimizing of under frequency load shedding scheme.