GB/T 20840.103-2020 Active

This part of GB/T 20840 provides definitions and explanations of power quality parameters, the impact of transformers on power quality measurement, and guidance for power quality testing. This part is applicable to electromagnetic and electronic transformers operating in the AC power (supply) system at 50 Hz, which have analog or digital output for use in electrical measurement instruments for measuring and evaluating power quality parameters. This part aims to provide guidance for using high-voltage transformers to measure power quality parameters. The power quality parameters in this part include grid frequency, supply voltage and current amplitude, flicker, supply voltage sag and surge, voltage interruption, transient voltage, supply voltage imbalance, voltage and current harmonics and interharmonics, signal voltage superimposed on the supply voltage, and rapid voltage changes. Note: The voltage ranges of low-voltage, medium-voltage, and high-voltage electromagnetic transformers mentioned in this part are as follows: low voltage refers to voltages below 1 kV AC, medium voltage refers to voltages above 1 kV and below 52 kV AC, and high voltage refers to voltages above 52 kV AC.