Li X.-F.,Guangdong Electric Power Research Institute |
Zhang W.,Shanghai JiaoTong University
Proceedings of the IEEE Conference on Decision and Control | Year: 2012
In this paper, a new sequential relay feedback method for the tuning of decentralized PID controllers in intelligent coordinated control systems (CCS). Based on the specified phase and gain margin, the parameters of the fuzzy self-adjusting PID controllers and the fuzzy gain scheduling PID controllers are determined. The scheme is implemented through the function code in typical DCSs (EDPF-NT, XDPS, etc). It has been used for control of the 300MW Fossil-Fuel units. The industrial applications show that the scheme achieves better performance in the specific range of load variations. © 2012 IEEE.
Peng X.-Y.,Guangdong Electric Power Research Institute
Gaoya Dianqi/High Voltage Apparatus | Year: 2011
The paper introduces line break failure and temporary treatment measures of 220 kV overhead transmission line, then gives the reasons for disconnection of wires through performance mechanical and electrical comparison tests of the broken samples such as pull test, current carrier and temperature rising test, electron microscopy test and energy spectrum analysis. Points out that as a long line running years, the wire had existed significant defects of machinery and electricity before the fracture, and then led to wire break under a small load current due to vicious cycle of local heat development and gradual loss of strength. At the end this paper, stresses the need to control load current and infrared temperature measurement to remove security risks of line, and suggests taking out technical transformation project of fault line as soon as possible.
Song J.H.,Guangdong Electric Power Research Institute
Materials Science Forum | Year: 2016
The Al-based amorphous ribbons were prepared by the copper roller melt spinning method, and then the laser brazing was carried out between aluminum alloy and aluminum alloy. Subsequently, the Micro Vickers Hardness Tester, Metallographic Microscope, Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) were used to characterize the hardness, morphology, micro structure and composition distribution of the welded joints respectively, so as to analyze the structural characteristic, performance characteristic and binding effect of the matrix metal joints. The results indicate that the prepared Al-based amorphous ribbon is of amorphous structure, the soldering point between aluminum alloy and aluminum alloy is well-connected and the joint’s hardness is identical to that of the base metal. The connection between the metal sheets can be achieved by using Al-based amorphous ribbon as solder, which could provide concrete references for the development and application of amorphous brazing in various fields. © 2016 Trans Tech Publications, Switzerland.
Luo Z.-J.,Guangdong Electric Power Research Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011
For the lack of the study of impact of random factors on the transformer and sympathetic inrush, this paper uses Monte Carlo method to simulate the characteristics of random factors change of the transformer and sympathetic inrush. Multi-channel operation components of PSCAD software is applied to simulate the different random factors, and by changing the state sequence mode of random factors, statistics closing switch model of the transformer and sympathetic inrush is set up. The model considers the impact of random factors such as the residual magnetism of the transformer, the non-synchronization of three-phase contact, initial closing phase, etc and field cases are combined to do statistical analysis. Simulation results show that the sympathetic inrush probability mode generated by series and parallel transformers at closing is uniform normal random distribution.
Tan J.,Guangdong Electric Power Research Institute
Lecture Notes in Electrical Engineering | Year: 2015
In order to analyze the impact mechanism of the valve flow characteristic on power oscillation, flow characteristics deviation of the steam turbine control valve is firstly analyzed and a coefficient for the deviation assessment is proposed; then, the model of generating unit coupled with dynamic system and electrical system is established according to the characteristics of deviation coefficient, with which the valve flow characteristics deviation is considered. Effect of flow deviation on power oscillation is analyzed by time-domain simulation. The simulation results show that the poor partial flow characteristics of the turbine valves are likely to cause power fluctuations and both the amplitude and the speed of oscillations are positively related to the extent of flow characteristics deviation. The conclusion can provide reference to research on the causes of power oscillations. © Springer International Publishing Switzerland 2015.