Zibo Power Supply Company

Zibo, China

Zibo Power Supply Company

Zibo, China
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Ha H.,Shandong University of Technology | Yu Y.,Zibo Power Supply Company | Zhang X.,Weihai International Airport | Mao J.,Zibo Power Supply Company
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012

Currently, most of the transient protections for high voltage direct current (HVDC) transmission lines utilize the rising rate of traveling wave to constitute the protection criterion. This approach lacks sensitivity information because of the significant attenuation to the high-frequency signal due to the frequency-dependent characteristics of long lines. This paper employs pole-zero method to analyze the frequency characteristics of the transient signal for faulty HVDC transmission line. It is discovered that the transient signals are consist of position main frequency components, which is generated by fault position, as well as boundary frequency components, which is generated by the boundary filters. The different characteristics between internal and external faults are mainly determined by the pass frequency band of the reflection coefficient and the choke frequency band of the refraction coefficient. Therefore, the feature band for distinguish internal and external fault is from the cutoff frequency of the stop band to the highest frequency of the pass band. Due to the zeros of the voltage in the feature band, the fault information in voltage will be counteracted. However, the differences of the current in the feature band are significant for there are no zero points in feature band. The simulation results by power system computer aided design (PSCAD) associated with the typical HVDC transmission system show that the differences of the current between internal and external faults are quite obvious. ©2012 State Grid Electric Power Research Institute Press.


Liu W.,Beijing Jiaotong University | Dou Z.,Beijing Jiaotong University | Wang H.,Zibo Power Supply Company
IEEE Transactions on Plasma Science | Year: 2015

Electrode structures have an important effect on the electric-field strength at the cathode tip in vacuum. Effectively increasing the electric-field strength at the cathode tip can contribute to increasing the density and energy of vacuum-arc discharge plasmas. In this paper, a tubular electrode is designed and employed as the anode. The electric-field distribution of the electrode was simulated using the software package Maxwell 3-D. Through a series of simulated experiments, the factors that affect the electric-field distribution were explored, including the length of the tubular anode and the relative positions of the electrodes. In addition, the effect of an insulator situated between the cathode and the anode and optimal designs for the electrode structures are discussed. The plasma parameters and thrust were measured using a Langmuir probe and a piezoelectric thin-film sensor, respectively. The experimental and simulated results indicate that optimizing the electrode structure can effectively reduce the weight of the electrodes, increase the field strength at the cathode tip, and generate higher plasma density and greater thrust. © 1973-2012 IEEE.


Wu X.,Qingdao University | Zhang Y.,Qingdao University | Wei X.,Zibo Power Supply Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2016

The steady-state performance of a Y-connected three-phase self-excited induction generator (SEIG) with unbalanced loads was analyzed, which focuses on the voltage variations of the SEIG. Based on the Z-parameter two-port network and the symmetrical component method, a two-port network model at load terminal was derived. By combining two-port network input port and output port, respectively, with positive sequence equivalent circuit and negative sequence equivalent circuit of the induction generator, a novel equivalent circuit model for supplying unbalanced loads was developed. The universally combined equivalent circuit was utilized to analyze asymmetrical steady state performance of a three-phase SEIG, which decoupled two variables and was of less operation time. The calculated values are in agreement with the experimental values for a sampled SEIG, which verifies the validity and accuracy of the presented method. © 2016 Chin. Soc. for Elec. Eng.


Wu F.-F.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | Liao R.-J.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | Yang L.-J.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | Liu X.-H.,Zibo Power Supply Company | And 2 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2013

An improved multi-component two-dimensional hybrid model is presented for the simulation of Trichel pulse corona discharge. The model is based on the plasma hydrodynamics and chemical models, including 12 species and 27 reactions. In addition, the photoionization and secondary electron emission effects are taken into account. Simulation is carried out on a bar-plate electrode configuration with an inter-electrode gap of 3.3 mm, the positive potential applied to the bar being 5.0 kV, the pressure in air discharge being fixed at 1.0 atm, and the gas temperature assumed to be a constant (300 K). In this paper, some key microscopic characteristics such as electric field distribution, net charge density distribution, electron density distribution at 5 different instants during a Trichel pulse are analyzed emphatically. Further more, the electron generation and disappearing rates, positive and negative ion distribution characteristics along the axis of symmetry are also investigated in detail in the later Trichel pulse cycle. The results can give valuable insights into the physical mechanism of negative corona discharge. © 2013 Chinese Physical Society.


Yang F.,Chongqing University | Liu X.H.,Zibo Power Supply Company | He W.,Chongqing University | Xiao H.G.,Chongqing University
Indian Journal of Physics | Year: 2013

Spatially two-dimensional and axial-symmetric plasma model is developed to investigate the characteristics of a bar-plate corona discharge of argon gas under atmospheric pressure. An improved nonlocal collision-less electron heat flux is used in the model. Numerical simulation for the process of argon corona discharge under atmospheric pressure are carried out with a separation of 0.2 mm between the bar and plate and the discharge is excited by an external circuit. The results indicate that metastable argon atoms are mainly produced by ground state excitation reaction, the metastable step-wise ionization is the dominated reaction and the highest contribution to electron production during the discharge. In addition, the maximum of electron temperature arises in the cathode sheath due to Joule heating in the high electric field. Elastic collision is the dominant volumetric electron energy loss in atmosphere corona discharge, which is negligible in low pressure glow discharge. The discharge current-voltage characteristic is predicted and shows a good agreement with the results obtained by experiments. © 2012 Indian Association for the Cultivation of Science.


He W.,Chongqing University | Liu X.,Chongqing University | Liu X.,Zibo Power Supply Company | Xian R.,Zibo Power Supply Company | And 4 more authors.
Plasma Science and Technology | Year: 2013

An improved self-consistent, multi-component, and one-dimensional plasma model for simulating atmospheric pressure argon glow discharge is presented. In the model, both the plasma hydrodynamics model and chemical model are considered. The numerical simulation is carried out for parallel-plate geometry with a separation of 0.06 cm. The results show that Ar* plays a major role in the discharge, which is mainly produced by ground state excitation reaction. The electron temperature reaches its maximum in the cathode sheath but maintains a low value (0.23 eV) in bulk plasma. Elastic collision is the dominant volumetric electron energy loss in atmosphere argon glow discharge, which is negligible in low pressure argon glow discharge. The metastable step-wise ionization is the main mechanism for electron production to sustain the discharge. However, the highest contribution to electron production rate is ground state ionization reaction. The bremsstrahlung power density is related to electric voltage. With the increase of the electric voltage, the bremsstrahlung power density increases, namely, the strength of ultraviolet radiation spectrum enhances in the cathode sheath.


Du J.,Shandong University | Zhu G.,Shandong University | Hou M.,Shandong University | Zhang N.,Zibo Power Supply Company
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2014

In distribution network, the construction of multi-contact switch can increase the load transfer path and improve the operating flexibility. However, it also brings a problem about how to make full use of the spare load capacity of the multi-contact switches in the distribution network fault restoration. The distributed intelligent feeder automation system can quickly complete the fault location, isolation and restore power supply. Therefore, the intelligent optimization power supply restoration algorithm of multi-contact distribution network based on distributed intelligent feeder automation system is proposed. Taking the least interrupted load as objective and the maximum use of the spare load capacity of contact switch as recovery rule, then the recovery program is determined by the topology of the non-fault zone and the concept of the boundary switch introduced, which can short the search space and time. The effectiveness and feasibility of the power supply restoration is verified by Simulation analysis. © 2014 IEEE.


Yang F.,Chongqing University | Liu Z.,Chongqing University | Luo H.,East Inner Mongolia Electrical Power Company Ltd | Liu X.,Zibo Power Supply Company | He W.,Chongqing University
IEEE Transactions on Magnetics | Year: 2014

In this paper, the meshless method is used to calculate the ion flow field under the high-voltage direct current transmission lines for the first time. The meshless local Petorv-Galerkin method is employed to solve Poisson's equation, and the upwind meshless method is applied to solve the current continuity equation. After the validity of the method is tested, the distribution of electric field and ion current density at ground level with different temperature and altitude of the transmission lines are discussed. The results show that the electric field and the current density are greater when the temperature and altitude are higher. © 1965-2012 IEEE.


Liao R.-J.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | Wu F.-F.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | Liu X.-H.,Zibo Power Supply Company | Yang F.,State Key Laboratory of Power Transmission Equipment and System Security and New Technology | And 3 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2012

Corona discharges are usually generated at sharp points, edges or on thin wires where the electric field is strongly concentrated. With the rapid development of extra and ultra high-voltage transmission lines, the air corona discharge becomes one of the critical problems associated with high-voltage lines, which can lead to the deterioration of insulation systems, power loss, radio noise. Corona discharge studies have been undertaken for many years, not only because of the scientific interest in the corona mechanism but also because of its practical engineering importance. Transient space charge distribution effect that is one of the important canses in the process of corona discharge, is closely related to the corona discharge mechanism and onset, self-sustaining. In this paper, we present an improved self-consistent, multi-component and two-dimensional plasma hybrid model for simulating the DC positive corona discharge under atmospheric environment. The model is based on the plasma hydrodynamics and the chemical dynamics, and it includes 12 species and 27 reactions. Besides, the photoionization effect is also considered in the proposed model. The simulation and the experiment on bar-plate electrode configuration with an inter-electrode gap of 5.0 mm at 2-5.5 kV are carried out. The discharge voltage-current characteristics and single pulse waveform are in good agreement with the experimental measurements. Based on this model, the electric field distribution, the electron temperature distribution, and the evolution of charged species distribution are investigated in detail. The results show that distributions of electron temperature and electric field have the same patterns, In the process of discharge, electron density is kept at 1019 m-3 or so. O4+ is dominant compared with the other charged heavy species, and O2+ and N2+ play the key role in secondary electron emission: the unmbers of O2- and O are the largest in negative ions and neutral particle respectively, they play a negligible role in discharge process. © 2012 Chinese Physical Society.


Qu K.,Shanghai University of Electric Power | Jin X.,Shanghai University of Electric Power | Xing Y.,Shanghai University of Electric Power | Ding Z.,Shanghai University of Electric Power | Chen W.,Zibo Power Supply Company
PEAM 2011 - Proceedings: 2011 IEEE Power Engineering and Automation Conference | Year: 2011

Based on six divided regions of space vectors, the potential position of the reference voltage vectors is firstly determined according to the principle of rotating vector normalization method. Then the effective time of three synthesized vectors is calculated by the principle of the volt-second balance principle. Last the working orders starting with the positive small vectors is proposed. Simulation results are included for verifying the validity of the proposed SVPWM method. © 2011 IEEE.

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