AVAILABLE TRANSFER CAPABILITY IMPROVEMENT USING TCSC.

摘要

When a power transaction could not be effected due to transmission constraints, the network is said to be congested. It can be detected by computation of ATC. Removal of congestion can be possible through ATC improvement. In the proposed invention, using the series compensation technique, being implemented by TCSC, ATC is shown to be improved. A methodology is developed to compute the compensation required, for ATC enhancement to a desired level. Also a criterion is suggested to install TCSC in a line thereby improving ATC of the network. The program "ATCIMPR1" is developed which can be used for determination of required compensation of one or more lines, to achieve desired amount of ATC. After knowing the required compensation to be provided for desired ATC, the design values are substituted in the equations constituting the TCSC reactance and firing angle. A computational program "SENSTCSC" is developed and a plot is obtained between TCSC reactance and the firing angle. After interpolation, firing angle is obtained for the required TCSC reactance. Realization of TCSC for ATC improvement is done using SIMULINK circuit model. Also a control circuit using PSIM is proposed which provides the firing angle as computed above. A small experimentation is carried out to validate the computed results of firing angle. All the programs are prepared in MATLAB for the implementation of developed computational algorithms. These programs are validated by comparing their results with that of obtained by Power World Simulator 11.0, which is a commonly used standard bench software for power system simulations. The IEEE 5-bus, 6-bus and 30-bus systems are considered for various simulations. As a real time case study, the SCADA data of 400kV Maharashtra State Grid is used. Simulation results are also obtained for this system. Following invention is described in detail with the help of Fig. 1 A showing Static Representation of TCSC, Fig. 1B showing Linearity between Change in Power Flow of line i-j and Change in Reactance of Line k-1, Fig. 1C showing Basic Thyristor Controlled Series Capacitor Scheme, Fig. 2 showing Flow Chart for Firing Angle Computation for required TCSC Reactance, Fig 3 of sheet 3 showing Activity Flow Chart for ATC Enhancement where Fig. 4A showing Variation of Change in Real Power Flow of Line Limiting ATC (Line i-j) against the Selected Line Compensations, Fig.4 B showing Variation of ATC against the Selected Line Compensations Fig. 5A showing ATC Variation for Change in Line Reactance of line L2-5, Fig. 5B showing TCSC reactance Vs Firing Angle.