Electric vehicles (EVs) require power converters that are efficient, compact, and capable of managing hybrid energy storage systems. Conventional designs use separate DC-DC converters for the supercapacitor and battery, which increases hardware count and losses. This paper proposes an integrated converter topology that combines the supercapacitor interface with the motor-side inverter through a modified auxiliary resonant commutated pole (ARCP) converter. The integration eliminates multiple DC-DC converters while enabling bidirectional energy transfer between the supercapacitor and the drivetrain during acceleration and regenerative braking, and providing soft-switching for the inverter during normal cruise operation. Simulation and experimental validation confirm the stability of DC-link functionality and the efficiency of energy transfer for various driving modes, such as acceleration, constant-speed operation, and regenerative braking. The converter provides soft-switching conditions for the main and auxiliary switches, resulting in a 51% reduction in total losses relative to a conventional hard-switched inverter. The results validate the design’s efficiency and practicality. By simplifying hardware, reducing passive components, and enhancing regenerative energy recovery, the topology provides a compelling option for next-generation EV propulsion systems with the potential to extend driving range, lower cost, and facilitate the wider utilization of sustainable transportation.

This paper introduces a new high step-up converter based on an interleaved structure. The topology achieves high efficiency by eliminating switching losses and reducing conduction losses. Fully soft switching condition is provided for all semiconductor devices. An auxiliary circuit is applied to ensure zero-voltage switching for the main switches. Moreover, the auxiliary switch operates under zero current switching (ZCS) with the help of the leakage inductor. Additionally, all diodes turn off under ZCS, eliminating their reverse recovery issues. The recovered energy from the leakage inductor further enhances efficiency. Furthermore, the switches' voltage stress are clamped well below the output voltage, allowing the use of switches with low . The topology also features continuous input current with low ripple. The operation principles, theoretical analysis and a comparison with other similar topologies are represented. To verify the accuracy of the suggested converter, experimental results of 30 to 400 V are provided.

This article introduces a fully soft-switched non-isolated high step-down/up bidirectional converter. The proposed structure utilizes two magnetic cores, one is the high voltage side inductor and the other is a multi-purpose core providing both high conversion ratio as well as soft switching condition. Soft switching is facilitated by the energy stored in the leakage inductance, enabling zero voltage switching for both main switches. The converter has the merits of wide input voltage range and reduced switch current stress due to extended duty cycle at high step-down state. Additionally, employing one of two main switches as a synchronous rectifier in each direction reduces conduction loss and enhances overall efficiency. Though utilizing four switches in its structure, the converter needs only three gate signals in each direction. All these features result in a highly efficient, easily controlled, with enhanced step-down/up conversion ratio. A prototype of the proposed converter operating at 100 W and 100 kHz with 400 V high side and 24 V low side voltages is implemented and the experimental results exhibit 97.84% / 97.5% efficiency in high step down/up directions.

The rapid growth of renewable energy harvesting and the integration of renewable energy systems into power systems have significantly increased electricity market attention towards utilizing Direct Current (DC) power systems. The protection of DC systems is still recognized as a challenge to their widespread deployment. Fast DC Circuit Breakers (CBs) are critical components required to ensure the safe and reliable operation of DC systems. Compared to Insulated-Gate Bipolar Transistor (IGBT)-based solid-state DC CBs presented so far, thyristor-based CBs benefit from reduced conduction losses and lower development costs. Nevertheless, this technology has drawn less attention due to the difficulty in the main DC CB valve commutation in the event of a DC fault. This paper presents a new topology for a unidirectional thyristor-based DC CB for low- and medium-voltage DC systems, addressing the above-mentioned challenges by incorporating a series capacitor block. Compared to the existing topologies presented in the literature, the proposed topology offers several key advantages, including fast operation response, high reliability, reduced main and auxiliary DC CB valves voltage stress, and reduced manufacturing cost. Detailed principle of operation is presented, and simulation results are provided using DC CB modeling in PSCAD/EMTDC software. In addition, a prototype 310 V DC CB with a nominal current of 3.1 A is designed, built, and tested as a scaled-down experimental testbed to verify the effectiveness of the proposed topology.

In this article, a high step-up three-winding coupled inductor DC-DC converter with the soft switching feature and high efficiency is proposed. The introduced converter provides high voltage gain compared to existing three-winding coupled inductor converters at a reasonable duty cycle. By reducing the turns ratio of the second winding, the voltage gain increases. With an active snubber circuit, the energy of the leakage inductance of the coupled inductor is effectively recycled, thereby limiting the voltage spike across the switch. The main and the auxiliary switches of the proposed converter turn on under zero voltage zero current switching (ZVZCS) and turn off under zero voltage switching (ZVS) conditions. Furthermore, all diodes are operated at ZCS conditions and the reverse recovery losses of diodes are eliminated throughout the entire switching cycle. So, the switching losses are reduced considerably and the converter achieves high efficiency. The converter has full soft switching operation under wide output power applications. In addition, the input current is continuous and a simple control circuit is achieved through a shared ground for the input and output. Featuring a reduced number of components, simple control circuit, and the use of low-cost elements, which leads to lower overall cost, the proposed converter is capable of providing high voltage gain and high efficiency. The proposed converter is analyzed and the theoretical analysis is confirmed through experimental results.

In this article, a fully soft switched high step up three level converter based on a Quasi-impedance source is introduced for use in photovoltaic applications. In the proposed converter, since an active switch is used instead of the diode in the impedance network, conduction loss associated with the diode is reduced, and zero-voltage-switching characteristics are provided in a wide range of output power for power switches, resulting in the improvement of efficiency. The proposed converter takes advantage of three level structure and it experiences much lower voltage stress on semiconductor elements compared to existing high step-up structures. This allows the use of mosfets with lower on the resistance, leading to reduced conduction losses and cost. Furthermore, the boost inductor in the input section not only maintains continuous input current, avoiding the need for bulky input capacitors, but also significantly optimizes power density and reduces cost. Other advantages of the proposed converter include high voltage gain with low duty cycle and the ability to turn off all diodes under ZCS condition. Experimental results from a 200-W laboratory prototype are provided to validate the proposed converter's performance.

This paper presents the design and simulation of a Proportional–Integral (PI) controller based on the Internal Model Control (IMC) strategy for a coupled-inductors interleaved boost converter topology. The modeling process begins with deriving the nonlinear state–space equations of the converter, where the transformer current and capacitor voltage are considered as state variables. A steady-state operating point is first selected, corresponding to the average values of current and voltage. The state variables and control signal are then linearized around this point by introducing small perturbations and applying a first-order Taylor expansion. Consequently, the equations are expressed in a linearized form. Using the Laplace transform, the small-signal transfer function between the duty-cycle perturbation and the converter output voltage is obtained. The resulting transfer function represents a second-order system with a Right-Half-Plane (RHP) zero. The IMC-based tuning rules are subsequently applied to determine the PI controller coefficients, achieving a balanced trade-off between response speed, stability, and noise sensitivity. The designed controller is then evaluated under various operating conditions, including changes in output load resistance, input voltage, and reference voltage, to validate its closed-loop performance. Simulation results confirm that the proposed IMC-tuning based PI controller achieves faster transient response and reduced overshoot compared with conventional PI-controlled interleaved converters.

This paper presents a new topology for a non-isolated single-stage microinverter for PV applications. The proposed structure integrates SEPIC and a buck–boost DC–DC converter, both operating in DCM to improve efficiency and stability. The topology employs four power switches, including two high-frequency devices and two low-frequency devices operating at 50 Hz. A common-ground configuration is adopted to eliminate ground leakage current. A simple digital control circuit ensures fast and reliable operation. The paper describes the operating principles and theoretical analysis of the proposed design. A 120 W experimental prototype with a 48 V DC input and 220 V AC output is developed to validate performance. Experimental results confirm the analytical findings and demonstrate the feasibility of the proposed microinverter for PV applications.

In this paper, a control-free battery charger based on an isolated resonant DC-DC converter is proposed for constant current (CC) and constant voltage (CV) charging of electric vehicle (EV) batteries. The proposed converter employs a current-driven synchronous rectifier (SR) and features load-independent output as well as a reduced number of switching components. Both CC and CV modes are intended to operate at a fixed resonant frequency with the help of LCC and LC resonant tanks, respectively. In the proposed converter, mode transition from CC to CV charging is carried out by reconfiguring the resonant tank without changing the switching frequency. The reconfiguration is realized by using a single auxiliary MOSFET to allow a smooth transition between the charging modes without requiring a bidirectional switch. In the CV mode, the auxiliary switch acts as a semi-synchronous rectifier (S-SR) and increases the efficiency. Additionally, in the CC mode, the current-driven SR technique is implemented to extract the switching timing directly from the resonant tank inductor current. As a result, by eliminating the external gate driver, a low-cost and simple implementation is achieved. A 1 kW prototype of the proposed converter with output voltages ranging from 250 to 450 V and an input voltage of 400 V is tested to validate the theoretical analysis and acceptable operation of the converter. The experimental results indicate a peak efficiency of 98.7%, which can be attributed to the reduced number of switching components, operation at resonant frequency, zero-voltage switching (ZVS), and zero-current switching (ZCS) operation of the proposed converter over a wide output voltage range under load fluctuations.

This paper introduces a soft-switching single-switch step-down LED driver. The switch operates under zero voltage switching condition, which eliminates switching losses as well as capacitive turn-on losses. The ZVS operation of the switch is maintained over a range of output current and voltage variations, which effectively enhances the overall efficiency. A load-independent output current is achieved in this structure with the proposed design, which allows the LED driver to operate without requiring an output current sensing and feedback loop, reducing the complexity of the converter. Additionally, the parallel resonant tank effectively reduces the voltage stress across the switch. Moreover, the leakage inductance of the transformer is absorbed into the series tank inductor and acts as a resonant component so that the leakage energy is recycled to the output. Finally, a prototype is implemented to supply a 50 W/30 V LED module at the switching frequency of 200 kHz from 150 V DC input, and experimental results are presented to validate the theoretical analysis. The efficiency of 95.3% is achieved using a low-cost MOSFET switch.

In this study, a novel fully soft-switched high step-up dc-dc converter is proposed. The proposed converter comprises the integration of boost and Cuk converters with the same input inductor and mosfet and series-connected output dc-link voltages. In this topology, the switch is turned-on under zero current switching (ZCS) and low-voltage conditions since the converter works under discontinuous conduction mode due to small output Cuk inductance. In addition, two coupled inductors are applied to create a similar voltage gain and soft switching conditions for all semiconductor elements. The first coupled inductor is placed in series with the Cuk diode, which provides a balanced dc link for wide load and input voltage variations and ZCS conditions for the Cuk diode. The second coupled inductor forms a lossless passive snubber to provide a zero-voltage switching turn-off condition for the main switch. This lossless passive snubber provides a clamped circuit and reduces the turn-off slew rate of the switch voltage. This snubber circuit is simple with minimum elements, and the snubber capacitor discharges to the output while the switch is off. Moreover, the input current is ripple-free, which is appropriate for renewable energy systems integration. The experiments substantiate the effectiveness of the proposed converter.

This study introduces a novel high-gain DC-DC converter by integrating a coupled inductor (CI) and a voltage multiplier cell (VMC) into the conventional SEPIC topology. An auxiliary switch, benefiting from zero voltage switching (ZVS), is applied to provide ZVS for the main switch over a wide output power range. Moreover, the employed diodes turn off under zero current switching (ZCS), thus eliminating reverse recovery losses and increasing efficiency. This study conducts a comprehensive analysis and compares the proposed converter with state-of-the-art topologies. The claimed features are verified by implementing a prototype that converts 36 to 250V.

This paper introduces a quasi-three-level high step-up boost converter that integrates multiple performance-enhancing features. Primarily, the inclusion of a Zero-Voltage Transition (ZVT) cell enables all switching devices to operate under soft-switching conditions, thereby minimizing switching losses and enhancing overall efficiency. The proposed configuration leverages coupled inductors along with voltage multiplier cells to achieve a significantly elevated voltage gain. Furthermore, adopting a three-level arrangement effectively lowers the voltage stress imposed on the main switches. To demonstrate the viability of the proposed approach, a hardware prototype is developed. Experimental evaluations, conducted on a 200-W laboratory prototype, confirm superior efficiency compared to conventional three-level converter counterparts.

This article presents a detailed analysis and design of a coupled inductor high step-down converter for 48 V-bus data centers. The proposed converter maintains the simplicity and low component count of conventional converters while extending the duty cycle and enabling soft-switching conditions for the mosfets. The proposed adaptive frequency control method adjusts the switching frequency proportionally to the output current to achieve zero current switching at light loads, where voltage regulator modules (VRMs) operate the majority of the time. This frequency control method is compatible with state-of-the-art VRM controllers with adaptive on-time features. Furthermore, this converter is adaptable to interleaved structures with phase-shedding capability, enhancing transient performance and power density. Finally, this article presents the steady-state analysis and experimental results of a 24 W prototype.

This paper presents a single-stage, single-switch forward-flyback converter for driving a dual-branch LED driver. Operating in Discontinuous current mode, the flyback stage enables automatic current sharing, eliminating the need for current control. A snubber capacitor enhances soft switching, reducing losses and improving efficiency. The proposed design ensures equal current distribution between LED branches just by utilizing one capacitor in its structure. Additionally, DCM operation minimizes the output current dependence to the output voltage variation of LED string according to temperature changes. The paper includes an operational analysis, experimental validation, and a comparative study with existing DC-DC converters.

A novel fully soft-switching interleaved high step-up converter is introduced in this paper. The suggested converter achieves high voltage gain using coupled inductors (CI) and a voltage multiplier cell (VMC). The main advantage of this design is its high efficiency, primarily achieved by eliminating switching losses and reducing conduction losses. An auxiliary circuit is employed to ensure zero voltage switching (ZVS) for the main switches, while the auxiliary switch itself operates under zero current switching (ZCS), addressing its switching loss. Regarding conduction losses, the low voltage stress on the switches allows for the use of switches with low on-resistance. Additionally, the interleaved technique reduces current stress on the switches, further improving conduction losses. Experimental results of the proposed converter, evaluated for a 30 V to 400 V conversion at 200 W output, are presented alongside theoretical analysis to validate its performance.

A soft-switched nonisolated dc-dc high stepup converter with a single switch is proposed in this article, which can be applied in photovoltaic systems. To achieve high voltage gain and reduce the components voltage stress, coupled inductors and switched capacitor techniques are integrated. A suitable lossless snubber circuit overcoming the lossless snubber challenges such as high component count and freewheeling conduction loss is employed to alleviate the switching losses along with the diodes reverse recovery problems. The lossless snubber circuit adds only two diodes to the proposed structure which is optimum in terms of component count among the soft-switching circuits. Using only one switch with reduced voltage stress and simple passive lossless snubber has contributed to the converter efficiency improvement and reduced control circuit complexity. Furthermore, the input current of the proposed converter is continuous, which facilitates the maximum power point tracking (MPPT) realization and enhances the converter performance. A complete analysis is provided to verify the converter operation, and a 200 W laboratory prototype with an input voltage range of 20 to 30 V and a fixed output voltage of 200 V, is implemented to verify the theoretical analysis. Also, a comprehensive comparison between the proposed and comparative topologies is described to illustrate the converter superiority.

This article presents a novel dc-dc converter for high-step-up applications. The converter combines an active-switched-inductor (ASI) circuit and a snubber circuit to increase gain and provide soft switching for all semiconductor devices. With the use of a single-core coupled inductor, high voltage gain is achieved. The snubber circuit further contributes to the gain enhancement. The switches turn-on under zero-current switching (ZCS) conditions, while all diodes operate under ZCS. In addition, the snubber capacitor provides zero-voltage switching when the switches turn-off. The low-voltage stress on the switches enables the use of switches with low on-resistance, which reduces conduction loss. In addition, the advantage of current sharing leads to a greater reduction in switch conduction loss. The theoretical analysis of the proposed converter is explained in detail. Furthermore, a prototype with an input voltage of 40 V and an output voltage of 400 V is implemented to demonstrate the efficacy of the proposed topology.

This paper introduces a soft-switched high step-up converter applicable to photovoltaic systems. In the proposed topology, to further improve the voltage gain and reduce the components voltage stress, coupled inductors and voltage multiplier cell (VMC) techniques are integrated with the conventional boost converter. Hence, it addresses challenges in traditional boost converter when operating at near unity duty cycle and enables it to utilize high-quality components that lead to decreased conduction losses in high-output voltage applications. Furthermore, the converter achieves soft switching operation by incorporating a lossless snubber cell, which consists of just two diodes and requires no additional switches and magnetic cores. These features contribute to enhancing the converter efficiency. Notably, the energy stored in the snubber circuit is effectively recovered to the output without any circulating current, making it a beneficial characteristic among the lossless snubber structures. The proposed topology also offers a common ground between the input and output terminals, as well as the switch which simplifies the converter control circuit. Additionally, it maintains continuous input current, which makes the proposed converter more suitable for photovoltaic system applications. To validate the converter benefits, a 150 W laboratory prototype converter is implemented.