Voltage Lift Technique Research Articles

A Novel High Gain Voltage-Lift Technique Based Transformer free Non-isolated Quadratic Boost Converter

A novel high gain voltage lift technique based transformer free non isolated boost converter is proposed with single switch operating at constant frequency in this paper. This performance of this converter is very good and high efficient compared to the conventional boost converters. The high gain is obtained by applying voltage lift cell to the quadratic boost converter. The simple structure, easy controlling and lower voltage stress. The operating principle with theoretical analysis and simulation results of proposed converter for various loads at 10 kHz frequency are discussed in this paper to compare the performance of this novel boost converter.

A Comprehensive Analysis and Hardware Implementation of Control Strategies for High Output Voltage DC-DC Boost Power Converter

Classical DC-DC converters used in high voltage direct current (HVDC) power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current) numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned deficiencies. The control strategy is based on classical proportional-integral (P-I) and fuzzy logic closed-loop controller to get high and stable output voltage. Complete hardware prototype of EHV is implemented and experimental tasks are carried out with digital signal processor (DSP) TMS320F2812. The control algorithms P-I, fuzzy logic and the pulse-width modulation (PWM) signals for N-channel MOSFET device are performed by the DSP. The experimental results provided show good conformity with developed hypothetical predictions. Additionally, the presented study confirms that the fuzzy logic controller provides better performance than classical P-I controller under different perturbation conditions.

High-Voltage DC-DC Converter Topology for PV Energy Utilization—Investigation and Implementation

This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power generation. The proposed power circuitry substantially improves the output power gain transfer ratio and a prototype hardware module is implemented using industrial standard DSP TMS 320F2812. Numerical simulation development followed by an experimental prototype implementation is carried out in this investigation. A set of numerical and experimental results is provided in this paper, which show close conformity with the theoretical background.

A new DC-DC converter based on voltage-lift technique

Summary In this paper, a new boost dc–dc converter based on voltage lift (VL) technique is proposed. There is any need for transformer, coupled inductances and sequential connections in the proposed boost converter topology. In this paper, the operating of proposed boost dc–dc converter in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) was discussed, and the current and voltage equations of the inductors and capacitors were obtained with details. So, the value of critical inductance and the operating of the proposed dc–dc converter between CCM and DCM were presented. The switching currents of each switch were analyzed. The switches, diodes, inductors and capacitors root-mean-square (RMS) current stresses were discussed. Finally, the correct performance of the proposed converter based on presented theoretical issues is verified by using simulation results on EMTDC/PSCAD software program and experimental results by using laboratory prototype. Copyright © 2015 John Wiley & Sons, Ltd.

Comparison of DC-DC Converters for Photo-Voltaic Application

Electricity demand is a major concern in the world today. To meet this demand, a number of natural sources are used for electricity production. The produced electrical energy from these natural sources will be given to consumers after going through a lot of conversion stages. So losses mostly occur in these conversion stages. In this paper the four existing converters CUK, SEPIC, Self-lift CUK and Self-lift SEPIC performances are separately compared and analyzed with each other. The voltage-lift (VL) technique is a popular method that is widely applied in electronic circuit design. This technique overcomes the effects of parasitic elements and increases the output voltage effectively along with high power efficiency and high power density with a simple structure. The operating principles of these converters are discussed and Simulation results are provided to verify and compare the feasibility of each systemwith solar photo-voltaic panel incorporated maximum power point tracking (MPPT).

Comparative study of current‐mode controllers for the positive output elementary Luo converter via state‐space and frequency response approaches

This study presents the comparative study of dual-loop current-mode controllers to achieve the output voltage regulation of the positive output elementary Luo (POEL) converter. The POEL converter is a fourth-order dc–dc boost converter developed using the voltage lift technique that gives a positive load voltage. Two current-mode controllers, one using the input inductor current and one using the output inductor current, are studied. Both state-space and frequency response approaches are used in the study to obtain a better insight of the comparative study. It is demonstrated that the controller using the input inductor current is more suitable for the regulation of the POEL converter. Experimental results showing the features of the controller in the presence of load and reference voltage changes are also provided to validate the theoretical conclusions.

AN IMPROVED LUO CONVERTER FOR HIGH POWER APPLICATIONS

Power conversion is one of the major requirements in various industries and in daily life. Among various types of power conversion, DC-DC conversion has greater importance. DC-DC conversion can be reliably performed using luo converter. It employs voltage lift technique so that output voltage is increased stage by stage, in arithmetic progression. Luo converter can be incorporated with the Z network or impedance network so as to ensure simple start up and smooth power conversion. An impedance network consist of two identical inductors and two identical capacitors connected in ‘X’ shape. Besides power conversion it also offers filtering operation. The luo converter in this scheme is of switched capacitor type. It helps to provide regulated output voltage from an unregulated source of power supply. The major benefits of this proposed scheme is that it combines the advantages of the switched capacitor, voltage lift technique and the impedance network. Hence the proposed scheme has various advantages such as high power density, larger range of output DC voltage, lower or no inrush current, lower harmonic injection, simple circuit, high voltage transfer gain, can process upto several tens of watts of power. The simulation analysis and the hardware implementation shows that the output voltage obtained is higher than the expected theoretical value. i.e, it is the highly boosted voltage output.

Super‐lift boost converters

Voltage lift technique has been successfully employed in design of DC/DC converters, for example, four series Luo-converters. However, the voltage transfer gain increases stage-by-stage in arithmetic progression. Super-lift converters largely enhance the voltage transfer gain, which increases stage-by-stage in geometric progression. It effectively enhances the voltage transfer gain in power series. This study introduces a novel approach - modified super-lift converters that implements the super-lift operation as well, its voltage transfer gain increases stage-by-stage also in geometric progression.

High Efficient Induction Motor Drives Using Triple Lift Converter

This paper proposes a high efficient advanced DC-DC converter by name Triple-Lift converter in the front end of Induction motor (IM) drives system. The conventional IM drives use PWM rectifier, boost converter, buck-boost converter, etc., in the front end which holds inadequacy in pump-up voltage and deprived output current. The Triple-Lift converter (TLC) implemented in the system employs voltage lift technique and produces the output voltage in arithmetic progression. The voltage source inverter (VSI) coupling IM derives a wide range of DC input (ripple free) from TLC which can be adopted for high rated motors with good efficiency. Simulation results using MATLAB show the effectiveness of the proposed converter arrangement for IM drives.

Hybrid split capacitors and split inductors applied in positive output super‐lift Luo‐converters

Voltage lift technique has been successfully employed in design of DC/DC converters, for example, three series Luo-converters. However, the output voltage increases in arithmetic progression. Super lift (SL) technique is the most significant contribution in power electronics, for example, four series SL converters. Their output voltage increases in geometric progression. This study introduces a novel approach - SL technique armed by split capacitors and split inductors that implements the output voltage increasing in higher geometric progression. It effectively enhances the voltage transfer gain in power series as well. From the authors experimental results, the power rates of these converters can be few kW.

Performance Evaluation of Positive Output Switched Capacitor Elementary Luo Converter with PI and Fuzzy Controllers

This paper presents simulation of PI and fuzzy logic controllers for a positive output switched capacitor elementary Luo converter which is a newly developed DC-DC converter. This combines both switched capacitor and voltage lift techniques. .Due to the time-varying and switching nature of the power electronic converters, their dynamic behavior becomes highly non-linear. Conventional controllers are incapable of providing good dynamic performance and hence fuzzy logic controller can be utilized as a feed forward controller for controlling power electronic converters. The control algorithm is developed in this work to ensure tracking of the reference voltage and rejection of system disturbances by successive measurements of the converter output voltage at certain time instants within a conduction period. The main objective is simulation of PI and fuzzy logic controls using MATLAB (version 7.0.1) software to evaluate the controller’s performances. The simulation results show that fuzzy controller performs better for the chosen converter.

Switched-Capacitorized DC/DC Converters

Switched capacitor DC/DC converters are new prototype of DC/DC conversion technology. Since switched capacitor can be integrated into a power IC chip, consequently, these converters have small size and high power density. Switched capacitor can be used in voltage-lift technique to construct DC/DC converters. The clue is that for the converters operating in discontinuous input current mode (DICM) the switched capacitors can be charged during the input current discontinuous period. The switched capacitors are charged to the source voltage during the switch-off period. They will join the conversion operation during switch-on period, and the stored energy in them will be delivered through further elements to the load. These converters are called switched-capacitorized DC/DC converters. Simulation and experimental results are provided for verification of this design.

Voltage-lift split-inductor-type boost converters

A series of voltage-lift (VL) split-inductor-type boost converters are proposed in this study. They can get much higher voltage transfer gains owing to the implementation of the VL technique. They have symmetrical structures that make them easily understood. Meanwhile, they retain the advantages of the elementary split-inductor-type boost converter, which consumes less energy and has lower-voltage stresses on active switches and diodes at the same circuit complexity level. Although there are four active switches in the multiple-lift circuits, they operate synchronously making the control algorithm much easier. An equivalent sliding mode controller is designed to evaluate the characteristics of the series of converters based on reduced-order state space modelling. Theoretical analysis is supported by simulation and experimental results.

Step-up DC–DC converter by coupled inductor and voltage-lift technique

A DC–DC converter with high step-up voltage gain is presented. The proposed converter uses the coupled inductor and the voltage-lift technique to achieve high step-up voltage gain. Additionally, the voltage on the active switch is clamped, and the energy stored in the leakage inductor is recycled in the proposed converter. Therefore the voltage stress on the active switch is reduced, and the conversion efficiency is improved. Finally, a laboratory prototype circuit with input voltage 12 V, output voltage 100 V and output power 35 W is implemented to demonstrate the performance of the proposed converter.

Voltage-lift-type Cûk converters: topology and analysis

The voltage-lift (VL) technique is an effective method that could be applied in electronic circuit design. A series of negative output dc–dc converters (Voltage-lift-type Cûk converters) applying series Cûk implementing VL techniques is introduced. Compared with the Cûk converter prototype, these converters can perform positive to negative dc–dc voltage increasing conversion with higher voltage transfer gains. They are different from other existing dc–dc step-up converters and possess several advantages, mainly including fewer switches, clear conversion processes and a high output voltage with the small ripple. Since the proposed converters avoid using transformers and cascade connection, the relative simple structures are beneficial to potential practical applications in future. A detailed theoretical analysis for continuous and discontinuous conduction modes is given. Both simulation and experimental results are provided to verify the main characteristics.

Series SEPIC implementing voltage-lift technique for DC–DC power conversion

The voltage-lift technique is an effective method that could be applied in electronic circuit design. A set of positive output DC-DC converters applying series SEPIC implementing voltage-lift techniques is introduced. Compared with the prototype of the SEPIC converter, these converters can perform positive to positive DC-DC voltage increasing conversion with higher voltage transfer gains. They are different from other existing DC-DC step-up converters and possess obvious advantages, mainly including fewer switches, clear conversion processes and a high output voltage with small ripples. Since the proposed converters avoid using transformers and cascade connection, relative simple structures are beneficial to potential practical applications in future. A detailed theoretical analysis for continuous and discontinuous conduction modes is given. Both simulation and experimental results are provided to verify the main characteristics.

Extra‐High‐Voltage DC‐DC Boost Converters Topology with Simple Control Strategy

This paper presents the topology of operating DC‐DC buck converter in boost mode for extra‐high‐voltage applications. Traditional DC‐DC boost converters are used in high‐voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC‐DC converters are limited. These limitations are overcome by using the voltage lift technique, opens a good way to improve the performance characteristics of DC‐DC converter. The technique is applied to DC‐DC converter and a simplified control algorithm in this paper. The performance of the controller is studied for both line and load disturbances. These converters perform positive DC‐DC voltage increasing conversion with high power density, high efficiency, low cost in simple structure, small ripples, and wide range of control. Simulation results along theoretical analysis are provided to verify its performance.

Ultra-lift Luo-converter

The voltage-lift (VL) technique has been successfully applied in the design of power DC/DC converters. Good examples are the three series Luo-converters. Using the VL technique can give high-voltage transfer gain. The super-lift technique has been given much attention since it yields high-voltage transfer gain. The ultra-lift Luo-converter is introduced as a novel approach to the new technology, ultra-lift technique, which produces even higher voltage transfer gain. Analysis and calculation illustrate the advanced characteristics of this converter.

Analysis of Luo converters with voltage-lift circuit

The voltage-lift technique using voltage-lift circuit has been successfully applied to several series of DC-DC Luo converters. However, the voltage-lift circuit definitely has an unavoidable influence on the overall converter performance. It is attempted to clarify such an effect. Four converters with voltage-lift circuit are analysed: positive output self-lift Luo converter, positive output super-lift converter, negative output self-lift Luo converter and positive output re-lift Luo converter. It is assumed that these converters operate in both continuous and discontinuous conduction modes. The converter performance in continuous conduction mode is first analysed. The boundary between continuous and discontinuous conduction modes and the modified voltage transfer gain are derived for each circuit. In addition, formulas for calculating the filling efficiency in DCM for the four converters are given. Both the simulation and experimental results verify the theoretical analysis.

Positive Output Multiple-Lift Push–Pull Switched-Capacitor Luo-Converters

Micro-power-consumption technique requires high-power-density dc/dc converters and power supply source. Voltage lift technique is a popular method to apply in electronic circuit design. Since a switched capacitor can be integrated into a power IC chip, its size is small. Combining switched-capacitor and voltage lift technique can construct dc/dc converters with small size, high power density, high-voltage transfer gain, high power efficiency, and low electromagnetic interference. This paper introduces a new series of dc/dc converters-positive output multiple-lift push-pull switched-capacitor dc/dc Luo-converters.