[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.5370/JEET.2018.13.2.550

Current Limit Strategy of Voltage Controller of Delta-Connected H-Bridge STATCOM under Unbalanced Voltage Drop

Son, Gum Tae (LS IS Co. Ltd.)
Park, Jung-Wook (School of Electrical and Electronic Engineering, Yonsei University)

Publication Information

Journal of Electrical Engineering and Technology / v.13, no.2, 2018 , pp. 550-558 More about this Journal

Abstract

This paper presents the current limit strategy of voltage controller of delta-connected H-bridge static synchronous compensator (STATCOM) under an unbalanced voltage fault event. When phase to ground fault happens, the feasibility to heighten the magnitude of sagging phase voltage is considered by using symmetric transformation method in delta-structure STATCOM. And the efficiency to cover the maximum physical current limit of switching device is considered by using vector analysis method that calculate the zero sequence current for balancing the cluster energy in delta connected H-bridge STATCOM. The result is simple and obvious. Only positive sequence current has to be used to support the unbalanced voltage sag. Although the relationship between combination of the negative sequence voltage with current and zero sequence current is nonlinear, the more negative sequence current is supplying, the larger zero sequence current is required. From the full-model STATCOM system simulation, zero sequence current demand is identified according to a ratio of positive and negative sequence compensating current. When only positive sequence current support voltage sag, the least zero sequence current is needed.

Keywords

Cluster balancing control; Delta-connected H-bridge STATCOM; Symmetric component current; Unbalanced fault;

Citations & Related Records

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