Investigation and Mitigation of Harmonics and Voltage Dip as A Power Quality Problems in Distribution Networks (Case Study: Adama Spinning Factory)

Abstract

In this study, harmonic distortion and voltage sag were investigated and proper mitigation techniques for the Adama spinning factory were provided. The DELAB NV8s PFC equipment is used to measure the voltage and current harmonic distortion levels on the four distribution boards. Although this equipment is primarily designed for automatic power factor regulation with 3-phase capacitor banks, it can also measure total and individual harmonic distortions for voltage and current up to 11th order. The measured voltage and current harmonic distortion levels were compared with IEEE power quality standards, and current harmonic distortion was found on the CMDB-1 and CMDB-3 distribution boards. The investigation also revealed that all of the CMDBs have voltage harmonic distortion that is considerably below the IEEE standard limit. Voltage sag was detected as another power quality concern during the CMDB-2 and CMDB-4 measurements.A DSTATCOM with synchronous reference frame theory has been suggested and modeled on MATLAB/SIMULINK to tackle the current harmonics occurring in the specified distribution boards. The simulation results without this compensating device demonstrate that the THDI of source current is 17.37% for CMDB-1 and 16.56% for CMDB-3. The THDI of source current for CMDB-1 and CMDB-3 was then reduced to 3.64% and 2.73%, respectively after the mitigation device has been connected. With the DSTATCOM connected to CMDB-1 and CMDB-3, the THDIof source current has been reduced by 79.04% and 83.51%, respectively. Another custom power device proposed and designed to eliminate voltage sag in the CMDB-2 and CMDB-4 of distribution networks is the Dynamic Voltage Restorer (DVR). The DVR has compensated for voltage sag caused by various symmetrical and unsymmetrical faults, as shown by simulation results. The simulation results, with and without the mitigating devices illustrate that the current harmonics and voltage sag have been compensated with the devices integrated to the network and these power quality issues have been reduced to below the IEEE standard limit.