Akademik Veri Yönetim Sistemi
14th. International Conference on Mathematics, Engineering, Natural and Medical Sciences (EJONS), Paris, Fransa, 6 - 07 Temmuz 2022, ss.61-73
According to the international standards, voltage sag is defined as a
10%-90% decrease in the effective value of the rated voltage at the grid frequency,
for more than 10 ms (0.5 period) and less than 1 minute. Voltage sags that
occur as a result of events such as short circuit faults, switching of large
loads, and lightning events are one of the most common power quality
disturbances in power systems that cause serious financial losses in industrial
facilities. Voltage sag sensitivity analysis; it is of great importance for the
manufacturer and the end user in the development of industrial devices
designed, in the process of obtaining production approval and certification. In
order to carry out studies related to the processes expressed; voltage sag
generators conforming to standards are needed. In this paper, a single-phase
voltage sag generator, in which the sag sensitivity tests can be made that
fulfils the conditions specified in the standards, has been designed and its
performance has been evaluated experimentally. In other words, it is aimed to
obtain realistic voltage sags in the laboratory environment with the proposed
waveform generator. In the design, 5 kVA adjustable alternating current power
supply (variac), solid state relay and programmable logic controller are used.
The magnitude of the voltage sag waveform to be applied to the device to be
tested was adjusted by variac. Zero-crossing triac-based solid-state relays
with fast switching feature are preferred for grid-variac and variac-grid
transitions. The on-time (sag duration) of the switching elements is controlled
via a programmable logic controller. Voltage sag duration data entry and
initial confirmation were performed with the touch panel. With the help of the
proposed voltage sag generator, voltage sag sensitivity tests of switching
elements such as contactor, conventional relay, slim relay, solid state relay
used in industrial automation systems were carried out. From the experimental
results obtained, it has been seen that with the proposed waveform generator,
voltage sag magnitude and duration can be adjusted on a large scale and
sensitivity tests can be performed in accordance with international standards.