Dong Fang Electrical Corporation Ltd

Deyang, China

Dong Fang Electrical Corporation Ltd

Deyang, China
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Zhang D.,Sichuan University | Zhang D.,Sichuan Engineering Technical College | Hou L.,Sichuan University | Wang R.,Dong Fang Electrical Corporation Ltd | And 3 more authors.
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2014

The speed sensor for yaw system of a wind turbine was vulnerable to external environment, which seriously degraded the yaw system reliability. According to these problems caused by the sensor installation, a sensorless control for a yaw motor was put forward to make wind effectively facing the yaw system. Since sliding mode observer was robust to the motor parameters and disturbances, a variable structure model reference adaptive system (VS-MRAS) observer for speed identification of the yaw motor was proposed. The response characteristics of speed and torque under Matlab/Simulink were compared and analyzed in these two cases which were the sensorless vector control systems based on the VS-MRAS and MRAS respectively. Simulation results show that the former is more suited to dynamic yaw system with high nonlinear and uncertainty, makes dynamic performance of the estimated speed better, and improves control precision of the yaw system. © Sila Science. All Rights Reserved.

Dan Z.,Sichuan University | Dan Z.,Sichuan Engineering Technical College | Li H.,Sichuan University | Rui W.,Dong Fang Electrical Corporation Ltd
International Journal of Simulation: Systems, Science and Technology | Year: 2016

Rotation precision of lathe spindle is an important indicator to measure the lathe performance. Owing to traditional Fourier transform lacking of locality and Wigner-Ville distribution having serious cross-interference, a method of rearrangement spectrogram was to extract the parameter of integrated error signal, which was picked up by the sensor in dynamic measurement system. Frequency estimation accuracy of eccentricity error caused when installing standard ball was improved by the method of rearrangement spectrogram, and then the eccentricity error was effectively separated by digital filter. The rotation precision on C616 with the proposed method in this paper was compared with DJ-HZ-1 machine tool rotation precision measuring instrument. Experimental results show that the proposed measuring method in this paper can be accurately measured the spindle rotation precision. © 2016, UK Simulation Society. All rights reserved.

Tang Q.,Dongfang Electrical Co. | Tang Q.,Sichuan University | Liu S.,Dongfang Electrical Co. | Shang L.,Dongfang Electrical Co. | Li Y.,Dongfang Electrical Co.
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2016

The design method of the teleoperation control system using industrial robot KUKA for was introduced the hazard environment and the control algorithm with heterogeneous master/slave structure. Using the Eth. KRLXML software package, a communication based on TCP/IP was connected between the robot controller and the remote computer. The joint angles and positions of the endpoint of the KUKA robot were sent periodically to the remote computer and commands from the remote computer were received and executed by the KUKA robot. Teleoperation control algorithm with relative scale transformation was adopted in the teleoperation system. Motions of the master manipulator was transformed to the slave manipulator's coordinate. By implementing the scaled relative position and pose transformation, the proposed control algorithm not only could be used in the designed heterogeneous master/slave structure, but also could satisfied different operation space requirements with high accuracy. Physical experiments verified the proposed teleoperation system and the proposed master/slave control algorithm. © 2016, Editorial Department of Journal of Sichuan University (Engineering Science Edition). All right reserved.

Yang S.,Sichuan University | Liu Y.,Dongfang Electrical Co. | Sun Y.,Sichuan University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2013

A method of position analysis for spherical mechanisms with four-bar closed-loop chains was proposed. The mechanism was divided into a four-bar closed-loop mechanism and a single-opened-chain (SOC) unit. The constraint equation of the four-bar closed-loop was established with spherical loop equation. The constraint equation of SOC was set up with coordinate transformation and direction cosine matrix. The coupled constraint equation of whole mechanism was built up based on spherical trigonometry. The proposed method was simple to set up constraint, easy for elimination and less extraneous root, which was helpful to obtain symbolic solutions or figure-symbolic solutions.

Zhu Z.,Extra Highvoltage Branch JiangXi Electrical Power Company | Li J.,Extra Highvoltage Branch JiangXi Electrical Power Company | Liu J.,Extra Highvoltage Branch JiangXi Electrical Power Company | Jiang H.,Dongfang Electrical Company
Advanced Materials Research | Year: 2013

With the build of Monitoring Center in our country, a great of signals are uploaded from many substations which are located on every corner. When an abnormal or a grid fault in Power System happens, lots of signals come out, then many operators on duty can't often react quickly and judge the fault accurately. Recently, more and more scholars begin studying intelligent alarm processing system. In this paper, by analyzing signals characters and SCADA network of Monitoring Center, an intelligent processing frame to alarms in monitoring center is provided, the frame includes three layers named signals foundation treatment layer, signals connecting and sharing layer, signals intelligent diagnosis layer. Now the frame has been implemented successfully in Monitoring Center of our company. At the same time, based on an virtual signals software, lots of devices alarms and grid faults are simulated, this intelligent processing system, which are built on the frame, always show the alarm tip quickly. Facts prove it attributes to grid fault judge for operators of Monitoring Center. © (2013) Trans Tech Publications, Switzerland.

He P.,Jiangxi Electrical Power Co | Zhu Z.,Jiangxi Electrical Power Co | Jiang H.,Dongfang Electrical Company
Advanced Materials Research | Year: 2013

In a centralized control center SCADA system, thousands of real-time data are sent to SCADA, including real-time signal, telemetering and alarm information. The intelligent analysis and processing of alarm signals is an important requirement. This article from the design point of intelligent alarm rules, explore an internal reasoning knowledge base and the external definition of rules combined design algorithm. Practical application results show that, the algorithm to power a variety of abnormal and fault has better capture and analysis ability. © (2013) Trans Tech Publications, Switzerland.

Tang J.,Central South University | Pu T.,Central South University | Pu T.,Dong Fang Electrical Corporation
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2011

The calculation of spiral bevel gear meshing stiffness is the foundation of dynamic analysis. An approximate sine or cosine series are applied for dynamic analysis, which influences the computational accuracy. Based on the theory of finite element analysis for spiral bevel gear with loaded contact, a computational method of spiral bevel gear meshing stiffness is developed, and the key technologies and pre-processing methods are given. A spiral bevel gear model with five teeth is constructed using ABAQUS software. The normal contact force and integrated elastic deformation are computed, and the meshing stiffness of single and multiple teeth are achieved considering the influence of difference loads. Computing results show that the loads have a major effect on the meshing stiffness amplitude and period, and that impacts of the loads on contact ratio and the contacting position need to be considered for the calculation of meshing stiffness. Comparing the results of the development calculation method with existing literatures for involutes spur meshing stiffness, the correctness of the meshing stiffness calculation method is verified, which lays the foundation of dynamic analysis for spiral bevel gear. © 2011 Journal of Mechanical Engineering.

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