High Frequency Interleave Technique Based on High Step-up Push-Pull Resonant Converter Modules

High step-up DC-DC converters are widely used in many industrial appliances and recently introduced in renewable energy systems and automotive applications due to their high voltage gain capability. Nevertheless, current high step-up converters often employ additional circuitry with the purpose of increasing the voltage gain. Consequently, the converter will be bulky, heavy and expensive, because the use of these additional passive and active components influences the power density and the cost of the whole application. Therefore, the well-known techniques of interleaving phases and magnetic coupling are applied in a novel high step-up converter with the purpose of helping tackle these problems. Using these techniques, high voltage gain and reduction of circuit elements can be achieved. In this paper, the operating principle of this converter is summarized and the voltage gain is analyzed. Moreover, the analyzed topology is compared with several outstanding high step-up converters recently proposed that use the concept of interleaving phases and magnetic coupling. Finally, the analyzed converter was experimentally tested and the effectiveness in terms of higher voltage gain and number of components than the current topologies is validated.

A low-cost isolated high step-up dc-dc converter with a single switch and multiple output cells is proposed. The magnetizing inductance of the multiple-winding transformer and a multitude of capacitors are used to form a parallel LC resonant link. The capacitors create a Zero Voltage Switching (ZVS) condition at turn-on and turn-off and reduce the switching losses of the switch and diodes. Rate of voltage change (dv/dt) on all semiconductors is limited by the link capacitors, and the diodes turn off with suppressed reverse recovery transients. The converter requires no auxiliary clamps or switches to achieve soft-switching. An analytical approach is developed to establish a relationship between link parameters, input and output voltages, and link frequency. Experimental results on a 60 V to 600 V converter at 250 W are included to corroborate the design and operation.

In this paper a novel high step-up multilevel boost converter using double voltage-lift switched-inductor (D-VLSI) cell is proposed. Series connection of conventional DC-DC boost converter is not a proper solution to achieve high voltage gain. Thus, DC-DC multilevel converters are employed to achieve high voltage gain. The proposed high step-up multilevel boost converter is a combination of double voltage-lift switched-inductor (D-VLSI) cell and voltage multiplier cell. In this paper double voltage-lift switched-inductor (D-VLSI) cell is used to enhance the step-up capability of multilevel DC-DC converter. Two switches, 2N+3 diodes, 2N+1 capacitor and two inductors are required to design the proposed N-level high step-up multilevel boost converter topology. Proposed high step-up multilevel converter circuit can be designed by using low voltage rating devices because blocking voltage across each power devices is low. The main advantage of proposed converter circuit is high voltage is achieved without using transformer, coupled inductor and high duty cycle. The gain of proposed multilevel converter is depends upon the duty ratio and levels present in voltage multiplier cell. Proposed DC-DC converter is designed for unidirectional power transfer applications. The proposed high step-up multilevel converter has been designed for three levels with rated power 300W, output voltage is 324V, input supply voltage is 12V, and switching frequency is 50kHz. The proposed high step-up multilevel converter circuit is simulated in MATLAB/SEVIULINK.

In this paper, a novel soft switching push-pull LC resonant DC-DC converter for energy sources is presented. In a high step-up converter, the input of primary side possesses low voltage and high current, so the losses caused by the current account for most of the total power loss. At the same time, the high-voltage stress of the high-voltage output components on the secondary side is also a major problem. Therefore, a high-gain isolated push-pull converter with a secondary-side resonant circuit is proposed, so that the primary-side switches have zero voltage switching (ZVS) and the secondary-side diodes have zero current switching (ZCS). The push-pull structure can reduce the number of active switches, so that the total power loss on the primary side can be reduced. The converter has a resonant tank circuit arranged between the secondary side of isolation transformer and the high-voltage output rectification module. The high-voltage output rectifier module adopts a full-bridge architecture suitable for high-voltage coupling connection. The low-side power switching module adopts a push-pull architecture suitable for low-voltage and high-current applications. The resonant tank circuit uses an inductor–capacitor (LC) structure to improve the resonant tank circuit, which achieves soft switching during power transfer, increasing the efficiency of the converter and improving the electromagnetic compatibility. The main advantage of this technology is that the secondary-side leakage inductance of transformer and the resonant capacitance are connected in series to achieve ZVS for switches and ZCS for diodes. Finally, a prototype of a high-gain push-pull resonant converter was established. The converter was operated at a fixed switching frequency of 135 kHz and a duty cycle of approximately 0.5. The efficiency of the converter can reach 97.1% under experimental tests at an output voltage of 400 V and a rated output power of 500 W.

This paper presents an alternative of pulse width modulation flyboost converter to achieve a regulated high voltage high power direct current power supply. The proposed flyboost converter in this paper composed with a conventional boost converter and flyback converter, which generated energy from the boost inductor during an off time period. Thus the higher-gain converter can be achieved in the proposed flyboost converter by the summation of both output voltage, boost and flyback converter. The circuit configurations, basic principle operation, mathematics analysis, design consideration and testing results of the proposed high gain step-up flyboost converter were described in detail. Finally, the results of a 20–30V input, 100V 100W output switched at 150 kHz flyboost converter, which was designed in this paper, showed the effectiveness of the converter was 87.26% and 2.76% of voltage regulation respectively.

High step-up gain Coupled Inductor Boost Converter (CIBC) discovers application in Distributed Generation System (DGS) to step-up voltage level of renewable energy sources. In DGS system, high step-up CIBC with a regulated output voltage and faster dynamic operation is required at various local loads. Transfer function of CIBC has one zero on Right Hand Plane (RHP). It is difficult to achieve high bandwidth when system has Non-Minimum Phase (NMP) characteristic. Peak Current Mode (PCM) control is the well-known technique to improve dynamic response in DC-DC converters. To design feedback controller and to analysis behaviour of CIBC, small signal model of CIBC is required. This paper presents small signal control-to-output voltage transfer function for PCM control of CIBC. Effect of artificial ramp is considered in derivation of this small signal model. A state space averaging method is used to derive small signal model. PI controller is designed using root locus technique. Time and frequency response of Voltage Mode Control (VMC) and PCM control of CIBC are compared. PCM control improves transient response and stability margin of CIBC for wide range of load variations. It also reduces effect of RHP zero. Simulation of CIBC using PCM control to get regulated output voltage is done in PSIM. Simulation results demonstrate that CIBC is able to get desire dynamic and steady state response of output voltage using PCM control under dynamic load conditions.

A novel high step-up high efficiency DC-DC converter for photovoltaic energy conversion is presented in this paper. The proposed converter employs a coupled inductor and two voltage multiplier cells to achieve high step-up voltage gain. The operating principle and the steady-state analyses of voltage gain are described in detail. A 200 W prototype with 20-30 V input and 400 V output voltages is built to verify the analysis. The maximum efficiency of the prototype is nearly 97.7% and the efficiency is higher than 97% over a wide load range.

This study proposes a novel isolated high step-up galvanic converter, which is suitable for renewable energy applications and integrates a boost converter, a coupled inductor, a charge pump capacitor cell, and an LC snubber. The proposed converter comprises an input inductor and thus features a continuous input current, which extends the life of the renewable energy chip. Furthermore, the proposed converter can achieve a high voltage gain without an extremely large duty cycle and turn ratio of the coupled inductor by using the charge pump capacitor cell. The leakage inductance energy can be recycled to the output capacitor of the boost converter via the LC snubber and then transferred to the output load. As a result, the voltage spike can be suppressed to a low voltage level. Finally, the basic operating principles and experimental results are provided to verify the effectiveness of the proposed converter.

This paper studies a battery-powered high step-up front-end converter for automotive audio amplifier. The proposed converter uses an interleaved structure with one-phase utilizing a conventional boost converter and the second-phase uses its inverted version. By this technique a high step-up voltage gain can be obtained as compared to the conventional two-phase interleaved boost converter. Operating principles and analyzes of the proposed converter topology is derived. Simulation and experimental results of a 120W circuit was made by a battery input voltage of 12V, while the reasonable duty cycle was sized to achieve an output voltage of 60V, corresponding to a static voltage gain Gv=5. The measured maximum conversion efficiency of the converter is 98.6%, and the efficiency at full load is 95.2%.

This paper presents a high step-up converter associated with a full-bridge inverter for livestock stunning applications. The proposed converter adopts a two-stage converter and uses partial energy processing to reduce voltage stress and switching loss, and to improve conversion efficiency. In addition, switches in the proposed converter are operated in a complementary manner to reduce component counts and circuit structure complexity. Compared with the conventional two-stage step-up converter and that with switch integration, the proposed converter can improve conversion efficiency of 4-6% over that with two-stage under full load condition, and can reduce cost of that with the switch integration. In this paper, mechanism of livestock stunning is first reviewed and then, the desired stunning voltage waveforms and parameter auto-tuning algorithm are proposed. The output voltage waveforms generated from the converter and inverter are with frequency varying from 50 Hz to 800 Hz, amplitude varying from zero to its breakdown voltage, as high as 200 V, and duty ratio changing from 0.3 to 0.7. Performance measurements from a prototype have verified the parameter auto-tuning algorithm and feasibility of the overall system design.

A 3-level boost converter substantiates integration and miniaturization by enabling higher voltage operation with lower voltage technology process, i.e. 2.5V devices are implemented to generate a maximum of 5V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub> , and concurrently providing inductor size reduction. However, flying capacitor balancing across a wide load and conversion range remains a challenge. This work proposes an auto-capacitor-balancing pulse frequency modulation (ACC-PFM) controller, combining peak and valley current mode control for continuous high step-up power conversion along with full-range V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub> regulation and embedded capacitor balancing. Moreover, a proposed delay-equalized level shifter generates duty ratios with only sub-ns deviations, resolving asymmetrical rising and falling delays that induce capacitor imbalance. It ensures the full-range operation for more than 90MHz inductor current frequency. This prototype is implemented in a 65nm CMOS process with 0.28mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area. Measurement results show that the converter achieves >7X step-up conversion and 96.8% peak efficiency, operating from 0.3-3.0V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">IN</sub> to 2.4-5.0V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub> with 83mA peak output current.

According to the poor stability of the output constant current and the control complexity of the existing Inductive Coupled Wireless Power Transmission System, a seriesparallel compensation network is applied to push-pull converter. And the soft switch is realized by configuring the parameters of compensation network, and the constant-current output of the wireless power is realized without additional complex control system. Firstly, analysis of the push-pull converter to achieve the conditions of soft-switching. Secondly, based on the leakage inductance model of the transformer, combined with the Thevenin equivalent theorem, the parameters of the string-and-compensation are designed. Lastly, the push-pull soft-switching inductive coupled power transfer converter is designed and built.The feasibility of theoretical analysis and parameter design method are verified by the experimental results.

This paper presents a single uninterruptible power supply topology that overcomes some drawbacks of the previous reported ones. Among the desired features of the proposed UPS topology are: small number of semiconductors, low battery voltage, flexibility for the selection of the input and output voltages, common neutral between the incoming AC line and the load. The proposed UPS is composed of three bi-directional step-up converters, where both the incoming AC line and the load are connected in differential mode across the output terminals of these step-up converters. A current limiter is introduced to improve robustness and reliability of the proposed UPS. In this paper, analysis and experimental results for both the line operating mode and backup mode are presented. In addition, the current limiter operation is experimentally verified under several load transient conditions.

In the conventional dc-dc converter, two sets of diode and adjacent passive component connected in X-shape can be applied to enhance voltage boost or buck capability, which is more suitable for high step-up or high step-down power conversion. This paper mainly investigates and compares conventional dc-dc converters and a family of diode-assisted dc-dc converter in wide range power conversion from aspects of silicon device, passive components requirements and efficiency. Then, a comprehensive comparison example of high step-up power conversion for power supply applications in future commercial aircrafts was carried out under the same operation conditions. Mathematical analysis and experiment results verify that diode-assisted dc-dc converters are very promising for high efficiency and high step-up or high step-down power applications.

In this paper, the generalized model of an inductively coupled power transfer (ICPT) system, which could transfer power efficiently, is built to predict the output power and voltage of the system. The basic concept and structure of ICPT systems is described and a current source push-pull resonant converter for ICPT is presented, and some characteristics of the ICPT system are discussed. The equivalent circuit model is built with mutual inductance concept. Based on this model, equations are obtained to calculate the output power, voltage and resonant frequency, which are verified by experimental results. A brief loss analysis based on Steinmetz equation is given to explain the difference between the predicted and measured values, which are verified by experimental results to make the model more accurate.