A New Cuk-Based DC-DC Converter with Improved Efficiency and Lower Rated Voltage of Coupling Capacitor

Abstract

DC-DC converters play a crucial role in recent and advanced applications, enabling efficient power conversion and management for renewable energy systems, electric vehicles, portable devices, and advanced communication systems. In line with this, the objective of this paper is to introduce a new DC-DC configuration based on the Cuk converter named as Mahafzah converter, which utilizes a coupling capacitor with a lower rated voltage. The paper aims to demonstrate the effectiveness of the proposed converter in terms of improved efficiency, reduced size, and reduced semiconductor device currents compared to the conventional Cuk converter. The proposed configuration comprises the same components as the Cuk converter, but in a different arrangement, without any additional elements. The main advantage of the proposed converter is using a coupling capacitor with a much lower rated voltage than the Cuk converter, resulting in a smaller capacitor size, reduced printed circuit board (PCB) size, and manufacturing cost. Additionally, the proposed converter reduces the currents of the semiconductor devices compared to those in the Cuk converter. To demonstrate its effectiveness, the converter is operated under continuous current mode (CCM) with a constant duty cycle and switching frequency. The study provides an in-depth discussion of the various operating modes by making use of equations relating to currents, voltages, duty cycles, and voltage gains. It also provides detailed illustrations of the limits between CCM and discontinuous current mode (DCM). The effectiveness of the proposed converter is demonstrated through a design example with operating parameters of 1 kW, 200 V/−300 V, and 20 kHz. Additionally, a low voltage–low power prototype (12/−18 V, 3.24 W, 20 kHz) is established to verify the operation of the proposed converter. Simulation and experimental verification of the proposed configuration achieved the desired results to improve efficiency and reduce the rate. The results clearly indicate that the efficiency of the proposed converter surpasses that of the conventional Cuk converter under identical operating conditions, reaching approximately 88% at rated load conditions.

A New Smart Grid Hybrid DC–DC Converter with Improved Voltage Gain and Synchronized Multiple Outputs

“…This paper proposes a new hybrid converter based on two combined, non-isolated DC-DC converters. The latter being a Zeta converter with a Mahafzah converter [32]. The proposed hybrid converter comprises one controlled switch, two diodes, two coupling capacitors, three inductors, and two low-pass filters.…”

“…Moreover, the proposed hybrid converter can supply three different loads, including one with inverted polarity. The In contrast to the conventional Cuk converter, the newly introduced Mahafzah converter [32], depicted in Figure 2, exhibits several notable advantages, including increased efficiency, a more compact footprint, and reduced semiconductor device currents. While the essential components of the Cuk converter are retained in the proposed design, they are arranged in a novel configuration without the need for any additional components.…”

“…The first one is the Zeta converter (Figure 1). The second one is the Mahafzah converter (Figure 2) [32]. Figure 3 shows the proposed converter.…”

“…The discussion that follows demonstrates proper converter parameter selection for CCM operation mode. The components of the proposed hybrid converter are selected based on the procedure used in [31,32].…”

A Single-Output-Filter Double Dual Ćuk Converter

“…In the traditional Ćuk power converter, energy transfer occurs through capacitive means, offering the advantage of integrating a capacitance voltage-divider feature. The Ćuk converter is the focus of several recent research investigations [15][16][17][18]. As presented in [15], the topology offers the possibility to handle bidirectional power flow using a voltage-doubler concept.…”