Akademik Veri Yönetim Sistemi
7th International Symposium on Innovative Approaches in Smart Technologies (ISAS2023), İstanbul, Türkiye, 23 - 25 Kasım 2023, ss.1-8
This paper investigates the impact of applying the
tap staggering Volt/VAr control method on the Online and
Adaptive Protection system. The tap staggering method utilizes
differences in taps between parallel transformers to create
circulating current, enabling the absorption of reactive power
from the grid to maintain network reactive power balance and
voltage. However, this reactive power absorption at the primary
substation through tap staggering poses potential risks for the
Directional Overcurrent (DOC) with the Load Blinder protection
scheme, which can result in faults or unnecessary alarms under
normal load conditions. In this study, simplified part of a
real network with the Wind Energy Sources was modeled in
PSS®CAPE, and four different operation scenarios were created
based on varying generation/demand profiles. The results indicate
that the operation of the DOC with Load Blinder scheme is
affected in all scenarios due to the changes in tap staggering,
altering short-circuit currents and the values of active-reactive
power measured by the Load Blinder Relay. A special macro was
developed to evaluate the network changes and adapt parameters,
including the DOC pickup (I>DOC ), Load Blinder maximum
resistance (RLB), and Load Blinder maximum angle (α), based
on the effects of tap staggering. Following the adaptation process,
an online adaptive system communicates the adjusted parameters
via the IEC61850 protocol and configures the real relay device
with the adapted settings. As a result, the protection system
operates reliably with the adapted protection scheme, enabling
more efficient power delivery from Wind Energy Sources to the
transmission system without interference from the protection
scheme or tap staggering operations.