Design and Implementation of PLC and SSR Based Single Phase Voltage Sag Generator

Yağız E., Uyar M.

14th. International Conference on Mathematics, Engineering, Natural and Medical Sciences (EJONS), Paris, France, 6 - 07 July 2022, pp.61-73

  • Publication Type: Conference Paper / Full Text
  • City: Paris
  • Country: France
  • Page Numbers: pp.61-73
  • Bursa Uludag University Affiliated: Yes


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.