A Simple Harmonic Reduction Method in 20-Pulse AC–DC Converter

Abstract

This paper proposes a simple and passive harmonic reduction method at dc link of 20-pulse rectifier. The 20-pulse topology is obtained via two paralleled 10-pulse ac–dc converters, each of them consisting of a five-phase (five-leg) diode bridge rectifier. For independent operation of the paralleled diode-bridge rectifiers, a zero sequence blocking transformer (ZSBT) is designed and implemented. Connection of a tapped inter-phase transformer (IPT) at the output of the ZSBT results in doubling the number of the output voltage pulses. The application of the pulse doubling technique with a low power rating (2% of the load power rating) results in a simpler and more economical configuration of the whole system and increased number of pulses. The design is suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The proposed structure is simulated using Matlab/Simulink software under different loading conditions. The simulation results confirm the significant improvement of the power quality indices (IEEE-519 standard requirements) at the point of common coupling (PCC). Experimental results are obtained using the designed and constructed laboratory prototype of the proposed converter to validate the design procedure and the simulation results. The VA rating of the magnetic circuit is calculated to confirm the savings in space, volume, weight and cost of the proposed configuration.

An improved 24‐pulse rectifier for harmonic mitigation in more electric aircraft

“…The proposed 24PR configurations are compared with 20PR [9][10][11]29], 24PR [22], 40PR [15,16], and 72PR [17,18] in [17,18,29], the cost can be estimated at 4.5 times of kVA rating of a transformer. Also, it should be emphasized that the total cost and size of the system are determined by the transformer magnetic rating.…”

“…This winding acts as a step-up transformer and results in a voltage increase and current decrease, which in turn reduces the current passing through PDC diodes and conduction losses, and therefore the suggested structure can be used in applications with high current loads. The IPT used in the conventional PDC [14][15][16][17][18] has only one winding, and the diodes are connected to this winding. Therefore, the load current flows through the PDC1 diodes, and as a result the conduction losses are considerable.…”

Multi-Phase Shifting Autotransformer Based Rectifier

“…It indicates that the kVA rating of the proposed forty-four rectifier is 42% while the current THD is less than 1.6%. Also, the kVA rating of the proposed rectifier is 21.98% less than the 40-pulse [29], 6.45% less than the 40-pulse [30], 15.26% less than the 40-pulse [31], 20.2% less than the 72-pulse [34], and 2.33% less than the 72-pulse [35] configurations. Table 2 includes an analytic studies between the number of diodes, magnetic rating comparison, and cost analysis for the proposed forty-four pulse configuration with 20-pulse rectifier [29]- [31], 36-pulse rectifier [35], 40-pulse rectifier [29]- [31], and 72-pulse rectifier [34], [35].…”

“…Many researchers have used different configurations based on 36 and 40-pulse rectifications for improved power quality have been described by Abdollahi [25]- [30], however, the THD of ac mains current with these topologies is more than 3% when operating at light load. The United States Military has imposed Military Standard 1399 upon its electrical designers and contractors.…”

Induction motor drive based on direct torque controlled used multi-pulse AC-DC rectifier

“…However, these topologies have high magnetic ratings and are therefore expensive. Increasing the number of pulses reduces the current THD but with the additional complexity and cost of MPRs [27][28][29][30][31][32][33]. On the other hand, the use of passive or active filters can also lead to current THD reduction [34][35][36][37][38][39][40].…”