Three-Winding Coupled Inductor Research Articles

Interleaved ZVS DC‐DC converter with ultrahigh step‐down and flexible gain

AbstractThis paper proposes a novel non‐isolated ultrahigh step‐down interleaved DC‐DC converter with an extremely extended duty cycle based on the series capacitor and coupled‐inductor techniques. The proposed converter utilizes a three‐winding coupled inductor (TWCI) to enhance the step‐down conversion ratio. In contrast to conventional coupled inductor‐based step‐down converters, its voltage gain improves as the turn ratio approaches unity. Consequently, coupled inductors have significantly lower winding losses. Furthermore, there is no extra constraint on the turn ratio of the TWCI. It results in a highly flexible voltage gain and more design freedom. Other advantages of the employed series capacitor and coupled inductor techniques can be listed as, zero voltage switching (ZVS) condition for all switches, significant reduction of the total switching device power (SDP) and recovery of the energy of leakage inductors. They all reduce power losses and costs. Steady‐state analysis, derivation of voltage gain and design considerations are discussed in detail. Finally, a 200 W, 400‐to‐12 V experimental prototype is implemented to verify the effectiveness and feasibility of the proposed converter.

Ultrahigh Step-Up DC–DC Converter Utilizing a Three-Winding Coupled Inductor and a Switched Capacitor Network With Reduced Input Current Ripple and Low Voltage Stress on the Power Switch

Ultrahigh Step-Up DC–DC Converter Utilizing a Three-Winding Coupled Inductor and a Switched Capacitor Network With Reduced Input Current Ripple and Low Voltage Stress on the Power Switch

A new soft‐switching high gain DC/DC converter with bipolar outputs

AbstractThis paper introduces a new single‐input multi‐output step‐up DC/DC converter with soft‐switching performance and low input current for renewable energy applications. The proposed topology uses a three‐winding coupled‐inductor (TWCI) and voltage multiplier circuits to achieve high voltage gains. The bipolar output voltages of the proposed converter can be varied independently by tuning the turns ratios of the TWCI. Due to the semi‐trans‐inverse specification of the suggested topology, high voltage gains can be obtained under a lower number of turns ratio in the magnetic device. Furthermore, a regenerative passive clamp technique mitigates the voltage stress on the single power switch. Additionally, the power dissipations are further reduced by considering a resonant tank in the circuit. In the converter, the parasitic leakage inductances of the TWCI windings help to provide the soft‐switching conditions for the switch and also to eliminate the reverse‐recovery loss for all converter diodes. The operating mode of the presented converter has been introduced and the steady state, along with the main operating equations have also been derived. Finally, the theoretical analysis is verified by a sample prototype 235 W at the input voltage 25 V and outputs of 200 V and −200 V.

A New Three-Winding Coupled Inductor High Step-Up DC–DC Converter Integrating With Switched-Capacitor Technique

A New Three-Winding Coupled Inductor High Step-Up DC–DC Converter Integrating With Switched-Capacitor Technique

A Full Soft-Switching High Step-Up DC/DC Converter With Active Switched Inductor and Three-Winding Coupled Inductor

This paper proposes a full soft-switching high step-up DC/DC converter with active-switched-inductor and three-winding coupled inductor (ASL-TWCI). By utilizing the three-winding coupled inductor (TWCI) with a modified switched capacitor cell, the voltage gain of the ASL-TWCI is further extended without requiring an extreme duty or a high turns-ratio of TWCI. Therefore, the voltage stress across the power switches is restricted. By utilizing the leakage energy of TWCI, all semiconductors achieve the Zero Current Switching (ZCS) performance, which has significantly reduced the switching losses of the ASL-TWCI. Additionally, the soft-switching performance is realized by utilizing few components, which reduces the losses and improves overall efficiency. Moreover, the construction of capacitor clamped cell has been adjusted to decrease capacitance and voltage rating, which significantly improve the power density of ASL-TWCI. The operating principles, steady-state analysis, design, and extensive performance comparison of ASL-TWCI are described in detail. Finally, a 400W prototype with 400V output voltage is fabricated to verify the theoretical analysis.

Soft-Switching Three-Port Converter With a Three-Winding Coupled Inductor

Soft-Switching Three-Port Converter With a Three-Winding Coupled Inductor

Ultra‐high gain quadratic boost DC–DC converter based on a three‐winding coupled inductor with reduced voltage stress for fuel cell‐based systems

AbstractHere, an ultra‐high gain quadratic boost DC–DC converter (UQBC) based on the conventional quadratic boost converter (CQBC) and a three‐winding coupled inductor (TWCI) has been proposed. It benefits from an extensive voltage gain range and low voltage stress on semiconductors. In addition, the converter requires a reasonable number of components. This structure is suitable for connecting renewable DC power sources like fuel cells to a DC‐bus in DC microgrids. Unlike CQBC, the produced conversion ratio has been improved to [1+n+m+d(1+n)]/(1−d)2 thanks to integrating a TWCI into CQBC. As a result, the proposed quadratic boost converter gives a better step‐up factor than previously presented quadratic boost converters (QBC). Meanwhile, the employed improvement method has not adversely affected some critical parameters like voltage stress on semiconductors or the input current ripple. This paper presents the mathematical analysis and operating principle of the proposed topology for both continuous and discontinuous current modes (CCM and DCM). Experimental results are represented to validate the converter theory and its performance. Results indicate that a high gain and efficiency have been obtained. Also, the voltage stress on the power switch is reduced by one‐fourth by choosing a proper duty cycle and winding coefficient.

A High Step-Up Integrated Buck-Boost-Zeta Converter Using Three-Winding Coupled Inductor With Current Sharing Considered

This paper proposes a high-gain Buck-Boost-Zeta converter with three-winding coupled inductor, which is generated by differentially connecting the Buck-Boost converter and the Zeta converter and integrating the coupled inductor multiplier cell. An active switched-inductor is obtained at the input side by differential connection, which is used as the primary winding of the three-winding coupled inductor, and the multiplier cell is composed of the secondary winding and diode-capacitor. The diode-capacitor circuit in the topology is multiplexed as a passive clamp branch to absorb the leakage energy and the ZCS turn-on of the switches is achieved. Therefore, the proposed converter achieves higher voltage gain and lower switch voltage stress. At the same time, the proposed converter retains the continuous output current characteristic of the Zeta converter. The operation principles and performances of the proposed converter are analyzed in detail. Meanwhile, the imbalance currents of the primary windings caused by the leakage inductance error is analyzed and the coupled inductor current sharing method is given, which effectively alleviates the current pulsation of the primary winding. A 400W experimental prototype is built to verify the theoretical analysis.

An Interleaved High Step-Up DC/DC Converter-Based Three-Winding Coupled Inductors With Symmetrical Structure

This paper proposes an interleaved high step-up converter based on three-winding coupled inductor (TW-CI) with symmetrical structure. By utilizing the TW-CI along with a voltage multiplier cell, the proposed converter achieves high power transfer ability as well as minimized voltage stress across power switches and diodes. The converter has significantly improved the voltage gain by integrating two TW-CIs with the passive clamp circuit. The leakage inductor energy of the TW-CI is recycled to improve the voltage gain and efficiency while facilitating the soft switching condition for the power switches. Additionally, the voltage stress across the power switches is decreased with the help of the clamping capacitors. Therefore, low-voltage-rated semiconductors with small on-resistance can be chosen which reduce conduction losses and improve the overall performance. Moreover, two series-connected capacitors of the primary side are introduced, which effectively balance the voltage between the power switches and the capacitors during steady and dynamic states. Finally, a 400W experimental prototype with 24V-400V is built to is verify the accuracy of proposed converter.

A New High Efficiency High Step-Up DC/DC Converter for Renewable Energy Applications

This article introduces a new nonisolated soft-switching coupled-inductor (CI) step-up dc/dc converter. The presented topology utilizes a three-winding CI (TWCI) along with a voltage multiplier circuit to increase the voltage conversion ratio without needing a high duty cycle. Using this circuit, a high voltage gain can be achieved without requiring a large number of turns ratio in the CI. The input current ripple of the introduced converter is very low, which is very desirable for renewable energy sources applications. The TWCI also creates an additional design freedom to increase the voltage gain, which indicates more circuit flexibility. Additionally, the voltage stress across the single power switch is limited with the help of a regenerative clamp capacitor. The leakage inductor of the CI is used to create a resonant tank to reduce power losses further. The leakage inductances help provide the zero-current switching conditions for the single power switch and decrease the reverse-recovery issues for all diodes, leading to an efficiency improvement. The operation principle, steady-state analysis, and design considerations are discussed thoroughly. Finally, the theoretical analysis is validated through experimental results obtained from a 200 W prototype with 250 V output voltage.

A High Step-Up Cost Effective DC-to-DC Topology Based on Three-Winding Coupled-Inductor

Owing to the low voltage level that renewable energy sources like solar panels frequently provide, and limited capability of simple boost converter, need for high gain step-up dc-to-dc converters are increased. In this article a single switch high step-up dc-to-dc topology with high efficiency is developed. To obtain high voltage gain, the described step-up dc-to-dc topology employs three windings coupled inductor and voltage multiplier cell method. To get the high voltage gain, this innovative converter does not require to work at a high duty cycle state by increasing the turns ratio of the coupled inductor. The suggested converter's working modes and theoretical model are investigated, and finally, a prototype setup is used to verify the theoretical and simulation analyses' correctness.

A High Step-Up DC–DC Converter With Three-Winding Coupled Inductor for Sustainable Energy Systems

This article proposes a high step-up dc–dc converter with a continuous input current that is suitable for sustainable energy systems. A three-winding coupled inductor, two power switches, three diodes, and three capacitors are utilized to perform the functions of active switched inductor and switched capacitor. By charging the two primary windings in parallel, and discharging the two primary windings in series to the intermediate capacitor and the output, the conversion ratio can be further improved with lower voltage stresses and current stresses on its power switches. In addition, the energy stored in the leakage inductance is recycled to reduce the voltage spikes of the power switches. Eventually, a laboratory prototype with an input voltage of 36–48 V, and output voltage of 400–600 V with a rated power of 600 W is implemented to validate the correctness and effectiveness of the theoretical analyses. The maximum efficiency and full load efficiency are 97% and 96.2%, respectively.

New Structure of Single-Switch Ultra-High-Gain DC/DC Converter for Renewable Energy Applications

This study introduces a new modified high-gain single-switch single-ended primary-inductor converter-based dc/dc converter. The low input ripple of the proposed converter makes it very suitable for renewable energy applications. In the proposed topology, a three-winding coupled-inductor and a voltage doubler rectifier are used to achieve high voltage gain without needing an extreme duty cycle. This circuit can provide an ultra-high voltage conversion ratio without requiring a large number of the turns ratio of the three-winding coupled-inductor (TWCI). Due to a regenerative clamped circuit, the leakage energy of the coupled-inductor is recycled; thus, the maximum voltage spike across the single-power switch is restricted. Therefore, <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> with a low maximum voltage rating can be utilized, which can alleviate the conduction power dissipations of the converter. Here, the switching power losses have been reduced significantly due to the circuit's soft-switching operation for the switch and all diodes. The steady-state analysis of the proposed converter is discussed thoroughly. Finally, the theoretical analysis is verified through the experimental results from a sample prototype (400-W, 25-400 V).

Parameter Extraction Technique for Evaluation of Inductive and Capacitive Elements of Three-Winding Coupled Inductor

Wide-bandgap devices have enabled miniaturization of magnetic components to enhance the power density of the converter. However, parasitic components become dominant at higher switching frequencies that actuate unwanted electromagnetic interference issues. Therefore, it is critical to model and evaluate them in compact magnetic structures. Since multiwinding coupled inductive structures are essential part of multiphase converters, this article introduces a measurement method to compute the parasitic elements of a three-winding coupled inductor. Results of the proposed method are verified by measuring the high-frequency emissions of the high-step-up converter with two inductor structures. Both inductors had similar inductances but different physical dimensions. With application of the proposed measurement methodology, parasitic capacitances of both inductors were computed. Results showed that one inductor structure has higher parasitic capacitance than the other. Since high-frequency emissions of the converter directly depend on the parasitic capacitance of the inductor structure, the emission profile of the converter showed that the converter indeed had lower noise peaks when the inductor with lower capacitance was employed. Hence, these results validate the capacitance trend as predicted by the proposed modeling technique. This method can be employed to any multiwinding coupled inductor to compute its parasitics to optimize the required electromagnetic interference filters.

Design and modelling of a new three winding coupled inductor based high step‐up DC–DC converter for renewable energy applications

This paper proposes a new three winding coupled inductor (TWCI) based DC–DC converter with high voltage gain capability. Continuous input current with low ripple, low number of components, simple structure, high efficiency, and common ground between input and output ports make it suitable for renewable energy applications such as photovoltaic (PV) systems. Voltage multiplier cells (VMCs) are utilized to enhance the output voltage and reduce the voltage stress across the power switch. The voltage gain can be adjusted by the duty cycle of the power switch and turns ratio of the TWCI. Thus, a flexible voltage gain is obtained, and there is no need for a higher duty cycle. On the other hand, the proposed converter has only one power switch with reduced voltage stress and low ON-state resistance. Therefore, a low-rated power switch can be used, which decreases the cost and volume of the presented converter. Operation principles, steady-state analysis, and comparison with other similar structures are provided. To frequency behaviour investigation, modelling and dynamic analysis are presented. Additionally, the effect of the proposed converter's parameters on the frequency response is evaluated. Finally, experimental results are presented to prove the effectiveness of the suggested converter.

A Single-Switch High Step-Up DC–DC Converter Based on Three-Winding Coupled Inductor and Pump Capacitor Unit

In this article, a novel single-switch, high step-up dc–dc converter based on three-winding coupled inductor and voltage multiplier circuit (VMC) is proposed. And on this basis, pump capacitor unit (PCU) is integrated to achieve a very high voltage gain. The converter makes full use of the advantages of three-winding coupled inductor, skillfully combines it with the VMC, and integrates the PCU that can be used in superposition to further improve the voltage gain. The voltage stress of the switch is reduced by using a passive clamping circuit to recycle the leakage energy of the coupled inductor. The operating principle and steady-state analysis of the presented converter in continuous conduction mode are introduced in detail. Moreover, the comparative analysis shows that under the same conditions, the proposed converter has higher voltage gain and lower voltage stress than others. Several advantages include high voltage gain, low voltage stress, low turns ratio of coupled inductor, and high conversion efficiency, make the proposed converter very suitable for new energy generation applications, such as photovoltaic systems. Finally, the feasibility of the proposed converter and the correctness of theoretical analysis are verified by a 500-W prototype at 50 kHz switching frequency.

Analysis of Switching Frequency Characteristics of Single-switch High Step-up DC-DC Converter with Three-winding Coupled Inductor

Analysis of Switching Frequency Characteristics of Single-switch High Step-up DC-DC Converter with Three-winding Coupled Inductor

A Novel Full Soft-Switching High-Gain DC/DC Converter Based on Three-Winding Coupled-Inductor

In this article, a new nonisolated full soft-switching step-up dc/dc converter is introduced with a continuous input current for renewable energy applications. The use of a three-winding coupled-inductor (TWCI) along with a voltage multiplier, enables the proposed converter to enhance the voltage gain with lower turns ratios and duty cycles. Also, a lossless regenerative passive clamp circuit is employed to limit the voltage stress across the power switch. In addition to zero current switching performance at the turn-on instant of the power switch, the turn-off current value is also alleviated by adopting a quasi-resonance operation between the leakage inductor of the TWCI and middle capacitors. Moreover, the current of all diodes reaches zero with a slow slew rate, which leads to the elimination of the reverse recovery problem in the converter. Soft-switching of the power switch and all the diodes in the proposed converter significantly reduces the switching power dissipations. Therefore, the presented converter can provide a high voltage gain ratio with high efficiency. Steady-state analysis, comprehensive comparisons with other related converters, and design considerations are discussed in detail. Finally, a 160 W prototype with 200 V output voltage is demonstrated to justify the theoretical analysis.

A Novel Single-Switch High Step-Up DC–DC Converter with Three-Winding Coupled Inductor

This paper introduces a single-switch, high step-up DC–DC converter for photovoltaic applications such as power optimizers and microinverters. The proposed converter employs two voltage multipliers cells with switched capacitor and magnetic coupling techniques to achieve high voltage gain. This feature, along with a passive clamp circuit, reduces the voltage stress across the switch, allowing for the employment of low RDSon MOSFET. This leads to low conduction loss of the switch. The diodes operate with zero-current switching at their turn-off transition, eliminating the reverse recovery losses. Additionally, the switch turns on with zero-current switching, leading to insignificant switching loss associated with its turn-on transition. The operation principle and steady-state analysis are presented and validated through experimental results obtained from a 140 W prototype of the proposed converter.

A New Three-Winding Coupled Inductor Nonisolated Quasi-Z-Source High Step-Up DC–DC Converter

This article presents a new three-winding coupled inductor high step-up quasi-Z-source dc–dc converter with single magnetic core and voltage multiplier techniques. Conventional quasi-Z-source-based dc–dc converters not only suffer limited voltage gain and high voltage stresses on semiconductors but also have utilized two or more magnetic cores in their structures. However, the suggested converter shares high voltage gain with continuous input current, low normalized voltage stresses on switch and diodes, low total voltage stresses on semiconductors, and common ground between input energy source and load. Also, this converter with single power switch and magnetic core has not limited the duty cycle. Furthermore, the proposed converter has good efficiency at high output voltage, and hence it is suitable for high voltage dc bus of three-phase inverters in renewable energy applications. The mathematical analysis, operating principle for the proposed converter, and comparison with other Z-source-based converters are provided. At last, a 400-W prototype is built in the laboratory, which has validated the accuracy of the proposed converter.