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Wen X.,Chongqing Electric Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2015

Since power system energy-saving and emission-reducing plays a significant and practical role in sustainable development for human society, the research overview of power system power-purchasing plan is presented from the perspective of energy-saving and emission-reducing. First of all, this paper indicates the research background and significance of power system energy-saving and emission-reducing; then, the processing manners are summarized for energy-saving and emission-reducing according to power dispatch plan and electricity market respectively. The overview of optimization methods for solving power dispatch plan and power-purchasing plan in electricity market are stated and analyzed, and these key problems are pointed out as well. Finally, those important research directions that need to break through are concluded and refined, while providing the reference for this area of research in depth. ©, 2015, Power System Protection and Control Press. All right reserved.

Zou W.,State Grid Electric Power Research Institute of China | Wu F.,State Grid Electric Power Research Institute of China | Liu Z.,Chongqing Electric Power Company
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011

Under a spot pricing based electricity market environment, a centralized charging strategy of plug-in hybrid electric vehicles (PHEVs) is proposed based on demand side response. A mathematical model is established taking into account the valley-filling effect of supply side and the users' cost. A dynamic estimation interpolation based algorithm is designed to optimize the mathematical model. Finally, a simulation based on an area's predicted data of year 2020 is made to show that, the proposed centralized charging strategy can not only lower the peak-valley difference, but also save users' cost, and achieve a win-win result. © 2011 State Grid Electric Power Research Institute Press.

Long H.,Xi'an Jiaotong University | Long H.,Chongqing Electric Power Company | Xu R.,Chongqing Electric Power Research Institute | He J.,Chongqing Electric Power Research Institute
Energies | Year: 2011

With the mass introduction of wind power in Northern China, wind power variability has appeared. In this article, both existing electric heat pumps (EHPs) and coal-fired combined heat and power (CHP) facilities, which are generally equipped with extraction-condensing steam turbines coupled with district heating for space heating purposes, are proposed to incorporate the variability of wind power equivalently. The authors' proposal arises from the facts that: (1) EHPs can provide space heating in the domestic sector with little thermal comfort change (e.g., energy carriers for space heating purposes can be switched from heating water to electricity); (2) coal-fired CHP units in Northern China can usually generate more electrical power corresponding to a shaved thermal power production. Thus, it is suggested that heating water from CHP units be shaved when the wind generation is low due to the variability of wind power, so as to enable more electrical power production and compensate for the corresponding insufficient wind generation. Following this, in the future and for some space heating loads at appropriate distances, electricity used as energy carrier should be converted by electric heat pumps for space heating. Thus, more electricity consumption will be achieved so as to avoid wasting wind power when the wind generation it is high. A numerical simulation is performed in order to illustrate the authors' proposal. It is shown that the impact of variability of wind generation can be equivalently reduced to a great extent, which enable more wind power integration instead of curtailment and potential energy conservation. Moreover, in contrast to before, both the thermal and electrical power of coal-fired CHP units are no longer constants. In addition, the ratio of electrical to thermal power of CHP units is no longer constant either, and results in less energy consumption compared with fixed ratio. Finally, electricity consumed by end users' EHPs, which are devoted to space heating for various spatial distances and time points, is figured out.

Long H.,Electrical Power Corporation | Xu R.,Chongqing Electric Power Research Institute | Xu K.,Chongqing Electric Power Company
2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings | Year: 2012

In China, there have been high penetrations of coalfired cogeneration facilities which are generally equipped with extraction-condensing steam turbines. Considerable coal is consumed in the power generation sector, and a lot of wind power resources may be abandoned simultaneously, which has been a ridiculous phenomenon in practice in Northern China. A proposal is given in this article, so as to enable the more integration of wind power. The authors suggest that if the energy carrier for part of the end users' space heating are switched from heating water to electricity [e.g. electric heat pumps (EHPs) can provide space heating in the domestic sector], the ratio of electricity to heating water load should be adjusted to optimize the power dispatch between combined heating and power (CHP) facilities and wind turbines. Finally a numerical simulation is performed to illustrate both the technical and economic feasibility of the aforementioned proposal, under ongoing infrastructures as well as electricity and space heating tariff conditions without changing participants' benefits. © 2012 IEEE.

Du Lin C.H.,Chongqing University | Jun L.,Chongqing Electric Power Company
Proceedings of 2012 IEEE International Conference on Condition Monitoring and Diagnosis, CMD 2012 | Year: 2012

This paper proposes an effective smart on-line over-voltage identification system based on a new layered recognition structure. The over-voltage is a main and great threat for the safety and stability of electric system. It's very helpful to analyze and identify over-voltage for improving power system insulation coordination. Through analysis of filed over-voltage data recorded by over-voltage on-line monitoring system, an over-voltage layered identification structure is presented for eleven kinds of common over-voltage. The wavelet transform and singular value decomposition theory are used to extract features of over-voltage. In consideration of the requirements of over-voltage recognition, the least square support vector machine is employed as the classifier to build a layered identification model, and the grid search algorithm is adopted to optimize the parameters of support vector machine to improve classification rate. The filed data testing results show that this system is feasible and promising for engineering application. © 2012 IEEE.

Liao R.,Chongqing University | Zheng H.,Chongqing University | Grzybowski S.,Mississippi State University | Yang L.,Chongqing University | And 2 more authors.
IEEE Transactions on Power Delivery | Year: 2011

This paper presents an integrated model based upon the fuzzy approach and evidential reasoning decision-making approach to condition assessment of power transformers. An assessing index system, including the DGA data, electrical testing, and oil testing, is established to facilitate the assessing model. The model is composed of two levels, that is, the fuzzy model and evidential reasoning model. The fuzzy model is proposed for generating the original basic probability assignments for the second-level model. Afterwards, an evidential reasoning decision-making model is utilized to combine all of the evidence and give an overall evaluation conclusion. Based upon this integrated model, a decision-making procedure is put forward to serve as an effective tool for transformer condition assessments. The results show that the assessing model is capable of offering an overall evaluation of the observed transformer condition. © 2011 IEEE.

Wang Y.,Chongqing University | Wan L.,Chongqing Electric Power Research Institute | Hu B.,Chongqing University | Xie K.,Chongqing University | Xiang B.,Chongqing Electric Power Company
Dianwang Jishu/Power System Technology | Year: 2014

The stochastic output characteristic of wind power generating units in wind farm is analyzed. Taking the operation strategy, working condition and charging/discharging constraints of energy storage system into account and through all sequential simulation, the operating characteristics and reliability of microgrid operated in isolated island mode are emphatically analyzed. Based on the idea of load partitioning and synthetically considering the two factors of the importance and the position of load, the load shedding strategy under isolated island mode of microgrid is researched. Finally, based on the features of island operation mode two novel reliability indices, namely the first average continuous working period of microgrid operated in isolated island mode and the rate of operational stability, are proposed, and using the two novel reliability indices the reliability evaluation of modified RBTS Bus6 is performed, and simulation results show that the proposed model and reliability evaluation algorithm are effective.

Liu H.-L.,Chongqing Electric Power Company
Applied Acoustics | Year: 2016

Partial discharge (PD) is one of staple reasons resulting in the deterioration of insulation system in power transformers and power faults. If the PD activity can be located at an early stage, preventive maintenance measures can be taken effectively. Therefore, the localization techniques of the PD do play an extraordinarily momentous role to enhance the operating reliability and stability of the system. It is proposed that a methodology based on the quantum genetic algorithm (QGA) adopting acoustic emission (AE) techniques for locating PD in power transformers. Results of the calculating example confirm the localization effectiveness and accurateness of the proposed method are ideal and satisfactory, and that precision of localization is enhanced compared to some other localization algorithms. The acoustic localization methodology based on the QGA is feasible and of suitability for the field applications. © 2015 Elsevier Ltd. All rights reserved.

Zhou W.-Y.,University of Sichuan | Lu F.-P.,University of Sichuan | Li H.,Chongqing Electric Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013

For solving the problem of slow calculation and low accuracy in the existing methods, a method that can get the operation mode combination of power system by genetic algorithm is proposed. Firstly the operation mode is mapped to nodal impedance matrix of power system. The fault current and branch parameters are expressed by the element of nodal impedance matrix. Then the mathematical model is established for getting the optimal combination of power system with the objective of smallest and biggest fault current and branch coefficient respectively. Finally, considering the feature of model which is discrete and nonlinear, the model is solved by genetic algorithm which can get the combination of power system in extreme case quickly and accurately. The correctness and practicability of the proposed method are verified by an example.

Yao Q.,Chongqing Electric Power Research Institute | Wang Y.,Chongqing Electric Power Company | Liu Y.,Chongqing Electric Power Research Institute
Gaoya Dianqi/High Voltage Apparatus | Year: 2010

Based on the decomposed theory of SF 6, the typical gas components under the different faults situation were pointed out in this paper. SOF 2 was the main decomposed production under the arc and over-heat. If the SO 2 can be detected under the heat decomposing situation, it would be the metal over-heat fault. If the contents of CF 4, CO and CO 2 increased, the fault would be related with solid insulation material. And the HF would be the typical gas of potential faults. So the GIS faults would be identified depending on the ana lysis of impurity components of SF 6.

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