Harmonic Elimination by Modern 3-phase Thyristor Controlled Reactor in Static VAR Compensators

Abstract

Controlled power is a fundamental necessity of various sectors and controlling of power is
made by Static VAR Compensators (SVC) is used with fast response time characteristics to
overcome compensation problems. This paper discuss about one of the FACT device i.e.
Thyristor Controlled Reactor (TCR) which is a part of SVC is used to compensate the
reactive power in transmission line and meeting the limit on harmonics.. A TCR scheme is
presented in this paper in which the total bank is split into one Δ connected reactor bank and
one Y connected reactor bank having same kVA rating and also consist of a low kVA rating
zigzag autotransformer, into place of the conventional Δ connected reactor bank with a
harmonic current filter. This arrangement averts the triple harmonics generated by the Y
bank from entering into the supply system because which is circulate in zigzag
autotransformer and at the same time, the combination results in cancellation of some major
harmonics from the source current. Thus, without using any additional filters, this topology
make easy reactive power control over a wide range and also meets the necessary harmonics
standards. The scheme is simple and provides an economic solution to the VAR compensation
problem.