Analyzing the Power Quality in a Power Supply System with a Predominantly Pulsed Load

A non-sinusoidal waveform of power supply voltage in electrical networks is a pressing problem due to the widespread use of electronic equipment both in power supply organizations and in electricity consumers. The article considers a study of non-sinusoidality in the 0.4 kV power supply system of an administrative-and-industrial building containing a load with pulse converters. Measurements carried out at the power supply system input and at the consumer connection points revealed systematic deviations of the voltage 3rd and 9th harmonic components' factors from their standard values stipulated by GOST 32144-2013. A correlation dependence between the voltage harmonic component and the apparent power at the fundamental frequency is obtained. The actual shares the power supply network and the consumer's load introduce in the voltage waveform distortion are estimated. It has been determined that the effect produced by the load at the power supply system input is expressed in an increase of the voltage waveform distortion by the 3rd harmonic component and decrease by the 9th harmonic component. The measurements were carried out by dedicated microprocessor devices of the BINOM3 type, which provide class A measurement features in regard of the power quality parameters and indicators.