Three-Phase Series Resonant DC-DC Boost Converter With Double LLC Resonant Tanks and Variable Frequency Control

Abstract

This paper proposes a three-phase inverter combined with two LLC resonant tanks series resonant DC-DC boost converter with variable frequency control. The three-phase inverter side of the proposed circuit is connected to identical two-level LLC tanks to ensure balanced resonant currents. The proposed converter requires less switching devices and transformers as compared to the conventional interleaved LLC resonant converter, which competitively offers higher efficiency and reduced size and cost. Furthermore, the proposed converter works above the resonant frequency to achieve zero voltage switching (ZVS) for the entire operating frequency range (42.5kHz <f s < 50kHz) for all switches. Variable frequency controller is considered in order to obtain better stability for diverse loads. Therefore, the proposed converter will have the ability to respond to the load changes by varying the switching frequency to the value that fulfils the requirement. In order to verify the improvement of the proposed converter, the converter performance is compared to conventional interleaved LLC resonant converter. The theoretical outcomes are confirmed through simulation studies using MATLAB/SIMULINK and validated experimentally using a laboratory prototype. Selected results are presented to verify the effectiveness of the proposed converter. INDEX TERMS Series resonant converter, LLC, zero voltage switching, variable frequency control.

Application of inductive coupling for wireless power transfer

“…In this system, it uses two separate coils which is L1 as first coil and L2 which is the second coil. The first coil L1 will attach to the source so it becomes transmitter and the second coil L2 will attach with the load therefore it becomes the receiver [12][13][14].…”

Design of a multifunction novel flexible fault current limiter for AC distribution network

“…However, the lack of voltage and current withstand level of a single power electronic equipment limits the development of power electronic FCLs, which also brings great challenges to the research on the limitation of short-circuit fault current in medium and high voltage distribution networks [10]. In order to resolve these problems and enhance the transient performance of distribution network, the multi-level and multi-inverter techniques have been adopted [11][12][13][14]. In [11,12], the multiphase LLC converter was proposed to achieve a great current-sharing performance without additional components or control, so that the overcurrent of single power electronic devices can be suppressed.…”

“…In order to resolve these problems and enhance the transient performance of distribution network, the multi-level and multi-inverter techniques have been adopted [11][12][13][14]. In [11,12], the multiphase LLC converter was proposed to achieve a great current-sharing performance without additional components or control, so that the overcurrent of single power electronic devices can be suppressed. For solving the problem of the overvoltage, the modular multilevel converter (MMC) was adopted in [13,14].…”

A Review on State-of-the-Art Power Converters: Bidirectional, Resonant, Multilevel Converters and Their Derivatives

“…Multilevel inverters (MLIs) are added to counter the problems associated with twolevel converters to meet the following criteria: (i) only sinusoidal output voltage shall be produced by the converter; (ii) the converter must have an output current of low THD. The advantage of MLIs is that the device voltage rating and the switching frequency can be significantly lower under the same output voltage compared to those of a conventional two-level converter; consequently, switching losses can be decreased remarkably, thereby improving the efficiency [32,[179][180][181]].…”