VOLTAGE SAG PLANNING OF A POWER SYSTEM WITH SPECIALLY CONNECTED TRANSFORMERS USING HYBRID DIFFERENTIAL EVOLUTION CONSIDERING ITI CURVE

Authors

Yao-Hung Chan, Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan, R.O.C.Follow
Chi-Jui Wu, Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan, R.O.C.
Ying-Pin Chang, Department of Electrical and Information Engineering, Nan Kai University of Technology, Nantou, Taiwan, R.O.C.

Abstract

This paper outlines the voltage sag planning of a power system with a three-phase to two-phase transformer. We compared systems with V-V and Scott connection schemes using the hybrid differential evolution (HDE) method to determine the design parameters by taking into account the ITI curves and coordination of over-current relays. The proposed model comprises a node admittance matrix for the calculation of voltage sag in order to determine the severity of system sag after single or two-phase faults. These analytical equations are useful in the mathematical determination of optimal design parameters. We also used the proposed method to obtain suitable values for the relay time multiplier and transformer impedance. Experiment results on V-V and Scott power systems demonstrate that the severity of voltage sag can be reduced through the tuning of relay settings and transformer impedance.

Recommended Citation

Chan, Yao-Hung; Wu, Chi-Jui; and Chang, Ying-Pin (2015) "VOLTAGE SAG PLANNING OF A POWER SYSTEM WITH SPECIALLY CONNECTED TRANSFORMERS USING HYBRID DIFFERENTIAL EVOLUTION CONSIDERING ITI CURVE," Journal of Marine Science and Technology: Vol. 23: Iss. 2, Article 8.
DOI: 10.6119/JMST-014-0515-2
Available at: https://jmstt.ntou.edu.tw/journal/vol23/iss2/8