Aspects of full load compensation with active filtering from a tests stand

Some Considerations Regarding the Measurement of the Compensation Efficiency in Three-Phase Systems

“…When nonlinear loads are connected to a power supplying network (PSN), the PSN and other linear consumers connected to it are affected [1,2]. Since the 1970s, with the widespread use of static power converters, these phenomena have intensified, affecting the periodic sinusoidal electric waveforms of absorbed currents and supply voltages.…”

“…Since the 1970s, with the widespread use of static power converters, these phenomena have intensified, affecting the periodic sinusoidal electric waveforms of absorbed currents and supply voltages. The non-sinusoidal supply voltages in the PSN adversely affect other consumers in the same PSN [2]. In addition, due to the occurrence of higher switching frequencies, electromagnetic interferences may occur, the PSN and other equipment in the vicinity of nonlinear loads being involved [3].…”

“…The greatest of them refers to the injection of current harmonics (and consequently of voltage harmonics) in the PSN, with unpleasant effects over the operation of some equipment and over the entire network. Unfortunately, there is no universal solution for this, instead solutions for particular cases (or solutions adopted such as to be applicable to an entire group of loads or equipment) were conceived [2,[19][20][21][22][23]. The adopted solutions refer to the use of active filters (shunt or series, depending on application) and/or hybrid filters, owing to the advantages provided by them as compared to the use of passive filters [19,24].…”

“…From a technical point of view, the efficiency of the use of filters can be evaluated taking into account both the total harmonic distortions (THD) of voltages and currents at the connection points of the loads to the PSNs, as well as the possible compensation of reactive energy/power fundamental harmonics-in the case of balanced loads [2,24,29,30]. Maximum values for (a group of) higher harmonic orders are also assessed and included in standards [7].…”

“…Answers for other questions must also be found, such as [2]: (a) Should a global evaluation be performed? (b) What techniques should be used to quantify the filtering efficiency?…”