Comparison of International Voltage Unbalance Standards Results for Different Power Quality Measurement Points: A Study on MV grid in Turkey

Voltage unbalance is generated by the increase or decrease of load connected to each phase, DERs that occasionally operates, voltage/current waveform distortion, voltage drop, reverse-power flow, etc. The phenomenon may cause rotational faults during start-up the machine, an increase in noise, and less torque in a motor. Also, it may cause a breaker to trip, transformers to overheat, or a loss increase in a capacitor smoothing rectifier, etc. Therefore, the aforementioned phenomenon needs to be well understood by both electrical system operators and end-users. Nowadays, there are more than one international standard that determines the measurement method and limit values of the voltage unbalance power quality parameter. In this study, it will be investigated which voltage unbalance standard would be the accurate approach for measurements in the distribution network by examining how different standards give results with real-time measurement in different measuring point values via the IEC61000-4-30 ClassA power quality analyzer.