North China Electrical Power University, State Grid Corporation of China and State Grid Shanxi Changzhi Power Supply Company | Date: 2015-01-30
The disclosure relates to the crossing field between a power transmission of an ultra-high-voltage and a power system simulation, specifically a method for analyzing an operation state of a substation by combining a whole grid model with a local grid model is provided according to the disclosure. The method includes following steps: performing a load flow calculation for the provincial grid to which a ultra-high-voltage line belongs, wherein initial data of the load flow calculation employs a grid model with E format for national power grid dispatching control center; making an equivalent transform for the model, forming an island independently from the provincial grid to which a ultra-high-voltage line belongs, and making a load flow calculation for the island to acquire data of node voltages and line transmission power.
Zuo J.,University of South Australia |
Zhao Z.-Y.,North China Electrical Power University
Renewable and Sustainable Energy Reviews | Year: 2014
Green building is one of measures been put forward to mitigate significant impacts of the building stock on the environment, society and economy. However, there is lack of a systematic review of this large number of studies that is critical for the future endeavor. The last decades have witnessed rapid growing number of studies on green building. This paper reports a critical review of the existing body of knowledge of researches related to green building. The common research themes and methodology were identified. These common themes are the definition and scope of green building; quantification of benefits of green buildings compared to conventional buildings; and various approaches to achieve green buildings. It is found that the existing studies played predominately focus on the environmental aspect of green building. Other dimensions of sustainability of green building, especially the social sustainability is largely overlooked. Future research opportunities were identified such as effects of climatic conditions on the effectiveness of green building assessment tools, validation of real performance of green buildings, unique demands of specific population, and future proofing. © 2013 Published by Elsevier Ltd.
Zhang S.,North China Electrical Power University
Renewable and Sustainable Energy Reviews | Year: 2012
During 2010 and 2011, China had been the largest producer of wind turbines in the world for two consecutive years. How China can transform from being the largest producer to being the strongest producer of wind turbines is currently a great concern in the industry. The purpose of this paper is to discuss this issue from the perspective of the international competitiveness of China's wind turbine manufacturing industry. Firstly, the paper establishes a model for evaluating the international competitiveness of wind turbine manufacturing industry, which consists of five first-level indexes and 10 second-level indexes. Then, the paper uses these indexes to evaluate the international competitiveness of six leading wind turbine companies in the world - Vestas (Denmark), Gamesa (Germany), GE Wind (the USA), Nordex (Spain), Suzlon (India) and Sinovel (China). The result shows that the international competitiveness of the Chinese wind turbine company, Sinovel, ranked the fifth, lagging behind Vestas, Gamesa, GE Wind and Suzlon. Finally, the paper makes in-depth analysis on the major factors that hamper the international competitiveness of China's wind turbine manufacturing industry and provides implications for future development of the industry. © 2012 Elsevier Ltd. All right reserved.
Wang Z.-G.,North China Electrical Power University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013
In this article, we tentatively identify the charmed mesons D J(2580), DJ*(2650), DJ(2740), DJ*(2760), DJ(3000), and DJ*(3000) observed by the LHCb Collaboration according to their spin, parity, and masses. Then we study their strong decays to the ground state charmed mesons plus light pseudoscalar mesons with the heavy meson effective theory in the leading order approximation, and we obtain explicit expressions of the decay widths. The ratios among the decay widths can be used to confirm or reject the assignments of the newly observed charmed mesons. The strong coupling constants in the decay widths can be fitted to the experimental data in the future at the LHCb, BESIII, KEK-B, and P̄ANDA. © 2013 American Physical Society.
Wang W.,North China Electrical Power University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014
In this paper we investigate the parallel texture structures with cofactor zeros in the charged lepton and neutrino sectors. The textures cannot be obtained from arbitrary leptonic matrices by making weak basis transformations, which therefore have physical meaning. The 15 parallel textures are grouped as 4 classes where each class has the same physical implications. It is founded that one of them is not phenomenologically viable and another is equivalent to the texture zero structures extensively explored in previous literature. Thus we focus on the other two classes of parallel texture structures and study the their phenomenological implications. The constraints on the physical variables are obtained for each class, which is essential for the model selection and can be measured by future experiments. The model realization is illustrated in a radiated lepton mass model. © 2014.
Wang Z.-G.,North China Electrical Power University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011
In this article, we study the strong decays of the newly observed charmed mesons D(2550), D(2600), D(2750), and D(2760) with the heavy quark effective theory in the leading order approximation, and tentatively identify the (D(2550),D(2600)) as the 2S doublet (0-,1-) and the (D(2750),D(2760)) as the 1D doublet (2-,3-), respectively. The identification of the D(2750) and D(2760) as the same particle with JP=3- is disfavored. © 2011 American Physical Society.
Tan W.,North China Electrical Power University
IEEE Transactions on Power Systems | Year: 2010
A unified PID tuning method for load frequency control (LFC) of power systems is discussed in this paper. The tuning method is based on the two-degree-of-freedom (TDF) internal model control (IMC) design method and a PID approximation procedure. The time-domain performance and robustness of the resulting PID controller is related to two tuning parameters, and robust tuning of the two parameters is discussed. The method is applicable to power systems with non-reheated, reheated, and hydro turbines. Simulation results show that it can indeed improve the damping of the power systems. It is shown that the method can also be used in decentralized PID tuning for multi-area power systems. © 2009 IEEE.
North China Electrical Power University | Date: 2015-04-19
Apparatus and method are provided for the treatment of uranium-contaminated soil by using comprehensive joint technology. The apparatus include the pumping system, the electrokinetic remediation system, elution system, remediation-separation system and recharge system. The remediation technologies (i.e. chemical, photolysis and electrokinetic) are used to remedy the uranium-contaminated soil. First, extract uranium from the contaminated areas and make the ionized uranium extract from the soil phase to the solution phase. Then, use the electrokinetic remediation technology to drive uranium enrichment electromigrate to near the anode. Finally, return the repaired-soil and groundwater back to anode area and recharge well, respectively. This comprehensive joint apparatus can reduce the uranium volume in the contaminated soil or water, and recycle the obtained uranium, which are cleaning processes and have no secondary pollution.
North China Electrical Power University | Date: 2015-12-23
This embodiment of the invention announced a synchrophasor measurement method applied to P class Phasor Measurement Unit (PMU). First, said measurement method is based on the dynamic phasor mathematic model. The low pass digital filter for phasor factors is designed, which is combined with DFT. It eliminates the spectrum leakage caused by the dynamic phasor inputs, and the raw phasor measurements after the spectrum leakage being eliminated can be obtained; the dynamic phasor is fitted by using the second order Taylor series. The linear relationship between the measurement errors caused the DFT averaging effect and the second order coefficients of the Taylor series is explored. And, the linear relationship is used to compensate the raw measurement errors under a dynamic condition. And, the accurate dynamic phasor measurements can be gotten. This measurement method can measure phasor accurately and rapidly under both static and dynamic conditions. The precision of the method not only meets the requirements in relevant standards, but also is an order of magnitude higher than the requirements of the standards.
North China Electrical Power University | Date: 2015-12-17
The disclosure provides a mercury removal system for a coal-fired power plant comprising: a mercury content monitoring system configured to monitor a mercury concentration in flue gas; a fly ash collecting device configured to collect fly ash from an electrostatic precipitator in the coal-fired power plant; a modifying device configured to be supplied with the collected fly ash and prepare a mercury sorbent from the fly ash; a sorbent injector configured to inject the mercury sorbent into flues of the coal-fired power plant so as to mix and contact with the flue gas in the flue and adsorb the elemental mercury in the flue gas. Thus, the concentration of the mercury pollutant emission is decreased.