Overview of application
IEC 555-2 (1982) is a regulatory standard that pertains to ac line disturbances, namely current harmonics. These current harmonics are caused by connecting household appliances and similar elec- trical equipment to a 230 V, 50 Hz ac mains. This standard establishes limits on the amount of har- monic energy electrical equipment can inject on the ac line to ensure that other devices connected to the ac power distribution system are not adversely affected. The generated current harmonics can vary or fluctuate with time (due to electronic products that cycle the ac line), or can have steadystate (quasi-stationary) characteristics.
When testing electronic equipment with a single phase ac input for compliance to the quasi-stationary part of this standard, it is necessary to have an ac source with low distortion and low output imped- ance to avoid introducing unacceptable measure- ment errors. The measurement instrument must use the required Rectangular (or Hanning) meas- urement window and must have the capability to return measured current amplitude data up to the 40th harmonic of the fundamental.
Agilent 6800 series features used
•RMS Voltage and frequency control
•Measurement window control
•Harmonic current measurement
Advantages/benefits of the Agilent 6800 series
•The 6800 series provides a “One-Box” Solution, so a separate power analyzer is not required for quasi-stationary harmonic measurements.
•The 6800 series provides an IEC 555 compliant Rectangular measurement window built into the standard unit.
•The low distortion, low output impedance and 16-bit measurement accuracy of the 6800 series provide full compliance to the measurement requirements.
Implementation details
How the 6800 series implements IEC 555 quasi-stationary harmonic current measurements
The output of the ac power source/analyzer is
set to 230 V and 50 Hz. The measurement window is changed from the default value (KBessel) to the Rectangular window. To perform the harmonic analysis, the ac power source/analyzer is sent a command to measure an array of harmonic current amplitudes. This array of current harmonics can be transferred to the computer for PASS/FAIL analysis versus the limits of the standard.
