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Study On Transmission Delay Of Networked Emergence Secondary Voltage Control

Posted on:2007-11-28Degree:MasterType:Thesis
Country:ChinaCandidate:W L ChenFull Text:PDF
GTID:2132360242461253Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
This paper studies the impact of the network time-delay to the performance of the networked power control systems. Take urgent secondary voltage control system for example, a power networked system framework is built, and then it gives a detail analysis of the distribution and composition of the network time-delay for the power systems. It has studied the performance of the pilot node's voltage amplitude under the certain delays and different jitter uncertain delays of the networked secondary voltage control system in emergency conditions.To solve this issue, firstly, this paper introduces an online time-delay-predict method. The basic principle is to use the last time's estimated time-delay value and the current sensor sampling period to derivate the current estimated time-delay value which is based on the recursion theory and the delay sliding window. Secondly, after having the current estimated delay value, this paper presents an extrapolation strategy, which is able to estimates the current data derived from historical data. This method determines the size of the time-delay sliding window and the extrapolation parameter values based on the different features of the measured data in steady-state conditions and transient conditions. In accordance with an algorithm guided by the historical data, and the estimated delay as the extrapolation steps, it can acquire the estimated current real-time data. An uncertainty time-delay-predict controller is designed according to this principle. The digital simulation results of the IEEE 3-machine 9-bus power system showed that this method can effectively restrain the oscillation of the pilot node's voltage amplitude caused by the network time-delay.
Keywords/Search Tags:NCS (networked control systems), urgent secondary voltage control, uncertain time-delay, online time-delay evaluation, changing data window extrapolation
PDF Full Text Request
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