Search Results (3)

In medium-voltage AC applications, multilevel converters are essential due to their ability to achieve high efficiency and significantly reduce total harmonic distortion (THD), ensuring improved performance and power quality. This paper presents a detailed analysis of the efficiency, power loss, and THD characteristics of multiplexed multilevel converters and neutral point clamped converters. Using MATLAB^®Simulink 2024b, the switching and conduction losses of both multiplexed multilevel converters and NPC converters are calculated. The three-level NPC converter offers advantages of a simpler design, reduced component count, and cost effectiveness with the drawback of low voltage quality. Simulation results validate the THD, power losses, and efficiency for the conventional three-phase three-level NPC converter and the three-phase multiplexed multilevel converter, and a detailed comparison is performed. Full article

This paper proposes a family of N-Branch hybrid switched inductor and capacitor (SLC) converters. With the single circuit, the multi-level output voltage or current could be generated. The proposed converter is suitable both for the voltage source and the current source. The same LC network is reused for different LC branches. The proposed converter is controlled by the phase shift control method with a time domain multiplexing concept. The N level circuit is operated with the same frequency. One cycle period is divided into N small time cycles for each branch. The phase shift for each branch is $360°/\mathrm{N}$. The load voltage could be changed by modifying the duty cycle of the transistor. When the SLCs work in the resonant condition, the soft switching will be acquired. The power loss of transistors could be sharply reduced. In this paper, a 300 W SLC converter is constructed to verify the theoretical analysis and operation mechanism in the resonant condition and hard switching condition. With the experimental and simulated verification, the soft switching and the stable multi-level output voltage or current are achieved. The proposed SLC converter could be used for the multi-level voltage power supply system, such as the electric vehicle, the electric aircraft, autonomous underwater vehicles (AUVs) and a new energy generation system. Full article

Flying-capacitor multiplexed modulation technology is suitable for bipolar DC microgrids with higher voltage levels and higher current levels. The module combination and corresponding modulation method can be flexibly selected according to the voltage level and capacity level. This paper proposes a bipolar bidirectional DC/DC converter and its interleaved-complementary modulation strategy that is suitable for bipolar DC microgrids. The converter consists of two flying-capacitor three-level bidirectional DC/DC converters that are interleaved in parallel 90°, and then cascaded with another module to form a symmetrical structure of the upper and lower arms; the complementary modulation of the upper and lower half bridges constitutes an interleaved complementary multilevel bidirectional DC/DC converter. If the bidirectional converter needs to provide a stronger overcurrent capability, more bridge arms can be interleaved in parallel. Once n bridge arms are connected in parallel, the bridge arms should be interleaved 180°/n in parallel. In bipolar DC microgrids, the upper and lower arms should be complementarily modulated, and the input and output are isolated by the inductance. To solve the current difference, caused by the inconsistent parasitic, the voltage-current double closed-loop-control is used, and the dynamic response is faster during bidirectional operation. This paper proposes theoretical analysis and experiments that verify bipolar bidirectional DC/DC converter for high-power energy storage. Full article