A robust 18-pulse diode rectifier with coupled reactors

Abstract

Abstract. The article presents the principle of operation and selected results of simulation and laboratory tests of the 18-pulse rectifier system with coupled reactors and small series active power filter. The presented system makes it possible to reduce, especially in distribution supply networks, undesired higher current harmonics. The 18-pulse nature of operation of the rectifier is reached using a set of coupled three-phase network reactors (CDT and CTR). The simultaneous use of the coupled reactors and the small active power filter provides opportunities for reduction of the supply current distortion, especially in case of voltage harmonic distortion and voltage unbalance.

Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems

“…In literature, 6-pulse or 12-pulse diode rectifiers are commonly described (with 18 and 24 pulse present as well [46,[50][51][52][53]). The first is built as a 6 pulse diode bridge consisting of six uncontrollable diodes and a low-pass filter for smoothing the DC current [54].…”

Suppression of Supply Current Harmonics of 18-Pulse Diode Rectifier by Series Active Power Filter with LC Coupling

“…Three system configurations are possible: (1) only 18-pulse rectifier, (2) rectifier with additional series reactor, and (3) rectifier with the series active filter. The main element of the system is the 18-pulse rectifier based on current dividing transformer (CDT) for preliminary current division, and the set of coupled three-phase reactors (CTR) [5]. The above magnetic elements compose three 3-phase voltage systems, shifted by 20 • in relation to each other.…”

“…If the galvanic separation is not required and there is no need to adjust the voltage between the supply line and the load, then the multipulse diode rectifiers with coupled reactors are a good solution. The main advantage, in comparison to multipulse converters with transformers, is the much smaller limiting power of the required electromagnetic elements, resulting in the smaller dimensions and weight of the entire rectifying device [5,6]. The downside is that when the supply voltage is unsymmetrical with higher harmonics it results in distortions of the supply current [5].…”

“…The main advantage, in comparison to multipulse converters with transformers, is the much smaller limiting power of the required electromagnetic elements, resulting in the smaller dimensions and weight of the entire rectifying device [5,6]. The downside is that when the supply voltage is unsymmetrical with higher harmonics it results in distortions of the supply current [5]. In such cases, it is advisable to use an additional smaller rated Series Active Power Filter (S-APF), which further improves the power quality [7].…”

Three-phase diode rectifier with current modulator in DC circuit based on multi-channel converter

“…Other proposed solutions use the PFCs based on multi-level converters [7,8]. Also, to correct the waveform of the power grid current the rectifier built with diodes (or thyristors) being interconnected by means of coupled inductors can be used [9]. Another solution of the rectifier system includes the voltage modulator in the DC circuit of a rectifier.…”