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Long H.,Postdoctoral Workstation of Chongqing Electrical Power Corporation | Long H.,Xi'an Jiaotong University | Xu R.,Chongqing Electric Power Research Institute | Ma J.,Henan Electric Power Research Institute | Wu K.,Xi'an Jiaotong University
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2012

Based on smart grid, remote control infrastructures were founded to manage combined heat and power generation and space heating end users. With mass introduction of electric heat pumps, space heating service could be shared by either heating water or electricity, which can adjust the ratio of hot water load to gross electricity load. New regulation was achieved between cogeneration and wind turbines, with the adjusted constraints of hot water and electricity load which performed as a certain space heating end use management, so that leads to the potential energy conservation. A model was put forward to simulate the requirement for COP of space heating performance of heat pump air conditioner and its energy-saving benefit. The results showed that the method can increase effectively grid connected electricity guantity of wind turbines in North China in winter.


La Y.,Guangdong Power Grid Corporation | Shi X.,Xi'an Jiaotong University | Cao W.,Polytechnic University of Mozambique | He B.,Xi'an Jiaotong University | And 3 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2013

Identification of the aging condition and the failure probability of oil-paper insulation in transformer is important for improving the reliability of electric power transmission system and applying life cycle cost (LCC) management to electrical equipment. Based on data obtained in a series of multi-accelerated-aging experiments, two approaches for calculating failure probability of oil-paper insulation were compared in aspects of degree of polymerization (DP) and condition ranking. In the experiments, mineral oil and cellulose paper are subjected to electrical and thermal stresses, and several parameters, including dissolved gases' volume fraction, furfural content, moisture content, and degree of polymerization, are measured after the aging process. Results show that weight of carbon oxide, which has a close relationship with cellulose paper degradation, is much higher in DP model than in condition ranking model. Moreover, it is concluded that DP model is more practically accurate than condition ranking model, because aging of cellulose paper rather than mineral oil is the key and critical factor of oil-paper insulation aging.


Li Z.,Chongqing University | Xu K.,Chongqing Electric Power Company | Xu R.,Chongqing Electric Power Research Institute | Long H.,Postdoctoral Workstation of Chongqing Electrical Power Corporation | Piao C.,Chongqing University
Lecture Notes in Electrical Engineering | Year: 2012

In view of the hybrid electric vehicle's Ni-MH battery system, the paper predicts the maximum charge and discharge power through artificial neural network. The maximum discharge and charge power directly affect the efficiency operation of hybrid electric vehicle. It is one of the most important parameters of Ni-MH battery systems. The estimation can avoid Ni-MH battery systems overcharge and over discharge phenomenon and prolong the service life of battery system. It has important practical value and theoretical significance for reasonable use of Ni-MH battery systems. Firstly from the view of engineering application, check the matching table to get the target value's relation with the SOC (the rest charge value), voltage, temperature. Secondly select some of the voltage, temperature and the last moment of the predicted maximum charging and discharging power, to be the input variables of the network. Thirdly through the tests, design and optimization the artificial neural network model structure. Finally get the artificial neural network model which can successfully predict the target. As a result, its error is within 10% to meet the expected requirements. © 2012 Springer-Verlag Berlin Heidelberg.


Long H.,Postdoctoral Workstation of Chongqing Electrical Power Corporation | Xu R.,Chongqing Electric Power Research Institute | He G.,Chongqing Electric Power Research Institute | Zhao Y.,Chongqing University | And 2 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2013

A method of wind-thermal power combined dispatch is presented, which regards the cogenerations and the centralized water-source heat pumps as the joint heat-source and carries out the coordinated control of joint heat-source and wind power to smooth the fluctuation of wind power output. It takes the minimized fluctuation of wind power output as its object and converts the transmission distance between heat source and heating end-user into the feeding time, which is then used as the key parameter of the combined dispatch. The insufficiency of daily peak-load regulation is calculated to reflect the impact of randomicity of grid-connected wind power output on the peak-load regulation capability of grid, which verifies the effectiveness of the combined dispatch method in reducing wind power fluctuation and increasing grid- connected wind power capacity.


Wang Y.,China Electric Power Research Institute | Wang Y.,Postdoctoral Workstation of Chongqing Electrical Power Corporation | Hou X.-Z.,China Electric Power Research Institute | Yang Y.-C.,China Electric Power Research Institute | And 2 more authors.
Beijing Youdian Daxue Xuebao/Journal of Beijing University of Posts and Telecommunications | Year: 2013

A new blind maximum Doppler frequency estimation algorithm is proposed based on channel frequency response envelope power spectral density (PSD) in orthogonal frequency division multiplexing systems. The subcarriers modulated by constant-envelope modulation are utilized. The PSD of received subcarriers magnitude is estimated by classic periodogram method. The maximum Doppler frequency is derived by searching the edge of envelope PSD and noise PSD. It does not need channel estimation used in conventional PSD method. Simulation shows that the estimation precision is increased and the performance is robust in a wide range of Doppler spread values.

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