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Sui X.,Dalian Power Supply Company | Tang Y.,University of Rhode Island | He H.,University of Rhode Island | Wen J.,Huazhong University of Science and Technology
IEEE Transactions on Power Systems | Year: 2014

Low-frequency oscillation is one of the main barriers limiting power transmission between two connected power systems. Although power system stabilizers (PSSs) have been proved to be effective in damping inner-area oscillation, inter-area oscillation still remains a critical challenge in today's power systems. Since the low-frequency oscillation between two connected power systems is active power oscillation, power modulation through energy storage devices (ESDs) can be an efficient and effective way to maintain such power system stability. In this paper, we investigate the integration of a new goal representation heuristic dynamic programming (GrHDP) algorithm to adaptively control ESD to damp inter-area oscillation. A particle swarm optimization (PSO)-based power oscillation damper (POD) has also been proposed for comparison. Various simulation studies with residue-based POD controller design, the proposed PSO optimized controller design, and the GrHDP-based controller design over a four-machine-two-area benchmark power system with energy storage device have been conducted. Simulation results have demonstrated the efficiency and effectiveness of the GrHDP-based approach for inter-area oscillation damping in a wide range of system operating conditions. © 2014 IEEE.

Piao Z.,ShenYang Agricultural University | Zhao L.,Dalian Power Supply Company
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

In recent years, the development and utilization of renewable energy has been paid more and more attentions. Wind power is becoming the cheapest and most promising green energy. With the development of wind power technology, the proportion of wind power to the traditional energy becomes larger and larger gradually. As for the limitation of geographical location in wind farm establishment, most of the wind power farm plants are built on the end of the power system, wind power has great impacts on voltage quality of the grid in the actual wind farm. By analyzing the causes of reactive power loss in the internal wind farm, on the assumption that ensuring the operating stability of the wind farm system, a wind turbine was used for generating reactive power to compensate for the voltage fluctuations of the gird system caused by reactive power through specific calculating, so as to meet the requirements of the network operating system stability. The results show that the method is feasible.

Wei X.-Y.,Dalian University of Technology | Sun H.,Dalian University of Technology | Xu F.-G.,Dalian Power Supply Company | Ma Q.,Liaoning Power Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2010

When the AC system is faulted, the voltage magnitude is varied at point-of-common coupling (PCC), normally accompanied with phase angle jump. Voltage source converter-high voltage direct current transmission (VSC- HVDC) systems with vector current controller (VCC) and dual vector current controller (DVCC) were presented and analyzed under balanced and unbalanced fault considering phase angle jump in PSCAD/EMTDC. The dynamic performance of VSC-HVDC with VCC and DVCC was investigated. The results show that DVCC can restraint 100 Hz oscillation with certain condition, but its dynamic performance is inferior to VCC and susceptible to phase angle jump, weakening the VSC-HVDC original superiority. © 2010 Chin. Soc. for Elec. Eng.

Wei X.,Dalian University of Technology | Sun H.,Dalian University of Technology | Wei X.,China Electric Power Research Institute | Ma Q.,Liaoning Power Company | Xu F.,Dalian Power Supply Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2011

This paper presented a new control scheme of dual vector current and harmonic compensation controller in the stationary αβ reference frame(αβ-DVCC&HC) to restrain the 2nd harmonic ripple on the DC link and 3rd harmonic in the AC currents under unbalanced AC grid conditions. The DC voltage ripple is restrained without need of sequencial-component decomposition that is with the defect of instability and weak dynamic performance, and the possibility of 3rd harmonic AC currents through the current control loop. Furthermore, the compensation control for 3rd harmonic currents improving the power quality is supplemented to decrease the AC currents distortion in the normal operation AC system due to the active power ripple. The voltage source converter based high voltage direct current transmission (VSC-HVDC) model and αβ-DVCC&HC have been represented in PSCAD/EMTDC, the results show its availability. © 2011 Chin. Soc. for Elec. Eng.

Ni Z.,South Dakota State University | Tang Y.,University of Rhode Island | Sui X.,Dalian Power Supply Company | He H.,University of Rhode Island | Wen J.,Huazhong University of Science and Technology
International Journal of Electrical Power and Energy Systems | Year: 2016

We investigate an adaptive neuro-control approach, namely goal representation heuristic dynamic programming (GrHDP), and study the nonlinear optimal control on the multi-machine power system. Compared with the conventional control approaches, the proposed controller conducts the adaptive learning control and assumes unknown of the power system mathematic model. Besides, the proposed design can provide an adaptive reward signal that guides the power system dynamic performance over time. In this paper, we integrate the novel neuro-controller into the multi-machine power system and provide adaptive supplementary control signals. For fair comparative studies, we include the control performance with the conventional heuristic dynamic programming (HDP) approach under the same conditions. The damping performances with and without the conventional power system stabilizer (PSS) are also presented for comparison. Simulation results verify that the investigated neuro-controller can achieve improved performance in terms of the transient stability and robustness under different fault conditions.

Shi W.,Dalian Power Supply Company | Feng S.,Liaoning Electrical Power Company Ltd | Xia Y.,NARI Group
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012

This paper proposes a new intelligent distribution automation terminal design scheme. Manual configuration and modify of remote protocol point table is replaced by self-describing function of IEC 61850-6 standard. The ICD self-description file can be generated automatically by the hardware encoder. Distribution master station can get the ICD file from the distribution automation terminal via FTP. The three remote tables information and the distribution network topology information can be parsed by the ICD file. SCADA system in distribution master station can realize the auto generation of front telecontrol protocol tables, graphics and database. © 2012 State Grid Electric Power Research Institute Press.

Zhu H.,Tongji University | Qu S.,Tongji University | Qi G.,DaLian Power Supply Company | Shen J.,Tongji University
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2016

High temperature oxidation resistance behavior of as-rolled Ti2AlNb-based alloy at 650, 700, 750 and 800℃ for up to 100 h exposure was investigated by means of isothermal oxidation tests in static laboratory air. Oxide layer morphology of surface and cross section, phase determination and element distribution of the as-rolled Ti2AlNb-based alloy, were evaluated using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) technology. Oxidation layer was hardly found at 650℃. Extremely thin oxidation layer was found at 700℃, while the thickness of oxidation layer increased significantly at 800℃. The results showed that the mass gain was significantly lower than 1 mg·cm-2, especially for exposures below 700℃, meeting the level of fully oxidation resistance. The mass grain increased and oxidation stratification was observed at 750℃, meeting the level of oxidation resistance. With the temperature increasing, the oxide layers delaminated obviously, but continuous oxidation films didn't form and obvious pores appeared in the oxidation films at 800℃. There were three kinds of oxides, including prismatic TiO2 phase, lamellar AlNbO4 phase and acicular phases. The higher the oxidation temperature was, the thicker the layers were, and the more harmful oxidation products formed. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.

Song W.,Dalian Power Supply Company | Sun X.,China Electric Power Research Institute | Wang J.,China Electric Power Research Institute | Lei X.,China Electric Power Research Institute | And 2 more authors.
Gaoya Dianqi/High Voltage Apparatus | Year: 2015

In this paper, the stability analysis of Dalian grid connected by the high capacity flexible HVDC is researched. Firstly, the flexible HVDC simulation model and actual Dalian grid is built in the PSCAD/EMTDC software. Secondly, the control strategy supplying to passive network is researched. Finally, the frequency/AC voltage additional control strategy of the flexible HVDC is studied. The simulation results show that the flexible HVDC can improve stability of Dalian grid. © 2015, Editorial Department of High Voltage Apparatus. All right reserved.

Yin S.,China Electric Power Research Institute | Zhang C.,Dalian Power Supply Company | Tian H.,North China Grid Company | Wang W.,Rongcheng Electrical Industry Home Company
Dianwang Jishu/Power System Technology | Year: 2012

At present the automatic report of the serial numbers of watt-hour meters is implemented by carrier sense multiple access/collision detect (CSMA/CD) mechanism that is widely applied in the ad hoc network schemes for low-voltage power line carrier communication, however a lot of leakage protectors act due to the carrier communication. In allusion to it, through the measurement of earth coupling capacitance and the analysis on working mechanism of leakage protector, it is found that the leakage protector may act while the intensity of high-frequency power line carrier signal exceeds a certain threshold value, and the root cause of such a phenomenon lies in that when the ad hoc network technology, which utilizes CSMA/CD mechanism, is applied to low-voltage power line carrier communication, because the number of concurrent carrier modules cannot be controlled, so the intensity of high-frequency power line carrier signal cannot be controlled as well and it leads to the action of leakage protector at user side. Following suggestions are proposed: the CSMA/CD mechanism is not suitable to low-voltage power line carrier communication system, and synthetically considering the effectiveness of the routing, economy of communication and stability of products, it is recommended to adopt central-controlled routing technology; in the construction of power consumption information collection system the risk possibly brought by CSMA/CD mechanism can be evaded by choosing the loading mode of issuing customer data achieves downwards.

Lin C.,Dalian Power Supply Company | Li C.,Dalian Power Supply Company | Guo Z.,Dalian Power Supply Company | Wang Y.,Dalian Power Supply Company | Song K.,Dalian Power Supply Company
Dianwang Jishu/Power System Technology | Year: 2012

To eliminate overvoltage in arc-suppression-coil earthed system caused by loaded-line breakage, the generation mechanism, waveform and discrimination of the overvoltage are researched. Firstly, the overvoltage in arc-suppression-coil earthed system caused by loaded-line breakage is theoretically analyzed in depth, and a method to calculate the overvoltage is given; secondly, the analysis results are verified by typical fault case and calculation example; finally, according to typical characteristic of overvoltage in arc-suppression-coil earthed system a method to discriminate line breakage fault is proposed. Analysis results show that in arc-suppression-coil earthed system, the loaded line breakage produces various types of resonance overvoltages, which are in-phase or reversed-phase to source voltage of the broken phase, the amplitude and property of the overvoltage are directly related to the load of the transformer in the line, and is influenced by compensation mode of the arc-suppression coil at the same time.

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