Three-Winding Coupled Inductor Research Articles

Analysis of a New Soft-Switched Step-Up Trans-Inverse DC/DC Converter Based on Three-Winding Coupled-Inductor

This article introduces a new nonisolated full soft-switching step-up dc/dc converter based on single-ended primary inductor converter (SEPIC) structure. The proposed topology utilizes a three-winding coupled-inductor (TWCI) to increase the voltage gain, but unlike other coupled-inductor-based converters, its voltage gain is increased by reducing its magnetic turns ratio. Moreover, the secondary and tertiary turns ratios of the TWCI can be used as an additional design freedom to extend the voltage gain, which indicates more converter flexibility. Due to the continuous input current, the proposed converter can be used for many types of renewable energy sources. Also, the leakage energy from the TWCI has further been recycled and transferred to the output with the help of a regenerative passive clamp circuit. Due to the soft-switching performance, the proposed converter has no switching losses at the turn- on instant for the power switch and reverse recycling losses of the diodes. Furthermore, the use of a small number of components along with the soft-switching performance offer high efficiency. Steady-state analysis and design considerations are discussed thoroughly. Finally, a 200-W prototype with 200 V output voltage is provided to verify the theoretical analysis.

A Study on an Improved Three-Winding Coupled Inductor Based DC/DC Boost Converter with Continuous Input Current

This paper proposes a novel high voltage conversion gain DC/DC boost converter for renewable energy applications and systems. The proposed converter utilizes a three-winding coupled inductor. The presented converter benefits from a unique advantage, as the actual turn ratio of the coupled inductor is decreased in the charging state of the coupled inductor. However, while the inductor is discharging, the actual turn ratio is increased. This feature leads to a very high voltage conversion gain. Furthermore, a passive clamp circuit is employed to recover the leakage current of the coupled inductor. The voltage stresses on the semiconductors are also reduced. In addition, the average current of the primary side of the coupled inductor is zero. This will reduce the total energy stored in the passive elements of the converter. The paper analyzes the Continuous Conduction Mode (CCM) and the operation principles of the presented converter are thoroughly derived. A 250 W laboratory hardware prototype is prepared to verify the proper operation of the presented converter. The obtained experimental results validate the feasibility of the presented converter.

Novel Three-Port Bidirectional DC/DC Converter with Three-Winding Coupled Inductor for Photovoltaic System

This study proposes a novel three-port bidirectional converter with a three-winding coupled inductor and applies it to a photovoltaic (PV) system to step up the PV system output to a dc bus or dc load while charging the battery. When the PV output is insufficient, battery voltage is stepped up to the dc bus voltage, and when the dc bus has excess energy, it is stepped down to charge the battery. Thus, a three-port bidirectional high step-up/step-down converter is achieved. A three-winding common core coupled inductor is designed and implemented in the converter, and a full-wave doubler circuit is used on the high-voltage side to achieve a high step-up effect. Power switches and diodes in the circuit are shared to achieve bidirectional operation. The output capacitors recover secondary-side leakage inductance energy in the step-up mode, and the third winding can be used to recover primary-side leakage inductance energy to reduce the voltage spike on switching in order to improve the converter’s conversion efficiency. A 500-W three-port bidirectional converter is implemented to verify the feasibility and practicability of the proposed topology. According to the measurement results, the highest efficiency of the PV step-up mode is 95.3%, the highest efficiency of the battery step-up mode is 94.1%, and the highest efficiency of the step-down mode is 94.8%.

High step-up three-level DC–DC converter with three-winding coupled-inductor

Due to the wide adoption of photovoltaic power generation, non-isolated high step-up DC–DC converters are becoming more and more popular. Among these converters, the switched/coupled-inductor-based converter is more attractive due to the fact that it has fewer power devices and a high efficiency. This paper presents a three-level high step-up DC–DC topology with a three-winding coupled-inductor. When compared with a conventional switched/coupled-inductor-based converter, a higher efficiency can be achieved, owing to low voltage stresses devices, fewer semiconductors in the power loop, lower current stresses, and ZCS of the main switches. The operating principle of the proposed topology is analyzed in detail via equivalent circuits, where a theoretical analysis is carried out using state space modelling. Experimental results obtained on a 24–300 V, 360 W lab prototype have verified the excellent performance of the proposed DC–DC converter.

Design and Implementation of Three-Winding Coupled Inductor and Switched Capacitor-Based DC–DC Converter Fed PV-TDVR

This paper presents a three-winding coupled inductor-based high-gain DC–DC converter fed transformerless dynamic voltage restorer (TDVR) to compensate the voltage sag, voltage swell and interruption in the single-phase power distribution network. The TDVR supported by the cascaded DC–DC boost converters offers high boosting gain. The cascaded connection of DC–DC converters reduces the efficiency due to the usage of more active and passive devices. The proposed PV-TDVR is designed to provide higher efficiency by reducing the number of power conversion stages with reduced numbers of active and passive components. The operating modes of the proposed PV-TDVR are presented in a comprehensive way. The MATrix LABoratory (MATLAB) simulation and 1-kV prototype model results are presented to analyze the performance of PV-TDVR in mitigating the voltage disturbances in the single-phase power distribution network.

High-voltage-gain DC-DC converter with three-winding coupled inductor

A novel DC-DC converter topology that uses a three-winding coupled inductor (TWCI) and a new voltage-multiplication technique is presented for achieving high voltage gain. The proposed converter comprises one boost unit, one passive absorption circuit, and two voltage-multiplier cells. The tertiary winding of the coupled inductor is connected to a capacitor and diode, and this combination acts as a secondary voltage-multiplier cell (SVMC). The SVMC, when combined with two capacitors, the secondary winding of the coupled inductor, a diode, and a switch, forms a primary voltage-multiplier cell, which can achieve a large voltage-conversion ratio that can be adjusted easily. The new voltage-multiplier technique can be used to decrease the number of capacitors and diodes, which improves the transformation efficiency. A prototype circuit with a nominal rating of 300 W is designed to verify the correctness of theoretical analysis.

A Cascaded Coupled Inductor-Reverse High Step-Up Converter Integrating Three-Winding Coupled Inductor and Diode–Capacitor Technique

This paper introduces a cascaded high step-up converter realized with a tightly coupled three-winding coupled inductor. Compared with existing high step-up converters, the proposed converter features that the smaller the turns ratio, the larger the conversion gain. So, the name coupled inductor-reverse is given to represent reverse-coupled inductor principle of operation. In addition, diode–capacitor circuit is introduced to not only recycle leakage energy to output, but also further lift voltage conversion gain. This paper illustrates operation principle of the proposed converter, discusses effect of leakage inductance on voltage gain, and deduces voltage and current stresses of components. Finally, a prototype rated at 400 W has been established, and experimental results verify correctness of the above theoretical analysis.

High Step-Up Converter With Three-Winding Coupled Inductor for Fuel Cell Energy Source Applications

This paper presents a high step-up converter for fuel cell energy source applications. The proposed high step-up dc-dc converter is devised for boosting the voltage generated from fuel cell to be a 400-V dc-bus voltage. Through the three-winding coupled inductor and voltage doubler circuit, the proposed converter achieve high step-up voltage gain without large duty cycle. The passive lossless clamped technology not only recycles leakage energy to improve efficiency but also alleviates large voltage spike to limit the voltage stress. Finally, the fuel cell as input voltage source 60-90 V integrated into a 2-kW prototype converter was implemented for performance verification. Under output voltage 400-V operation, the highest efficiency is up to 96.81%, and the full-load efficiency is 91.32%.