Cuk Converter Research Articles

CUK-SEPIC Hybrid Converter

Abstract: Electricity derived from renewable energy sources are unpredictable and intermittent in nature. Continuous power supply is a challenging task, obtained by maximum utilization of two or more resources resulting in a hybrid system. This work proposes a fused converter topology for a hybrid solar/wind system extracting maximum power. The hybrid configuration permits the sources to feed the load individually or simultaneously based on its availability. The proposed converter is the integration of Cuk and SEPIC converter. The characteristic feature of Cuk-SEPIC Hybrid converter is that it provides uninterrupted and constant voltage to dc micro grid applications. The suitability of proposed system at practical operation condition is demonstrated through simulation result using MATLAB/Simulink followed by an experimental validation

A comparison of P5, Cuk and class E 2 converters for WPT in EV battery charging

This paper presents three DC-DC converter topologies, P5, Cuk and a class E2 converter to compare their performance in the context of wireless power transfer for electric vehicle battery charging. The comparisons use MATLAB simulation to explore the abilities of the system to produce the desired outputs, efficiency, and ability to operate under changing load and coupling factor conditions. The paper highlights current issues with resonant DC-DC converters for wireless electric vehicle battery charging. It also serves to draw parallels between the new application of Cuk and P5 converters for WPT, and that of the Class E2 topology which is better understood within the context of wireless power transfer. The promising feature of Buck-Boost DC-DC converters for wireless power transfer is the ability to control output voltage from the duty cycle. This controllability opens new avenues for creating robust systems under varying coupling factors and loads. The Buck-Boost converter-based systems also benefit from a reduction in overall converters needed and a lower operating frequency than that of Class E2 converters.

Performance Analysis of DC-DC converters for Solar PV fed Switched Reluctance motor for Electric Vehicle Applications

This paper describes the performance of a Solar PV-powered switched reluctance motor with low torque ripple in electric vehicle applications. The prominence of switched reluctance motors has become significant in the electric vehicle industry, because of its ineradicable characteristics like simple structure, absence of rotor windings, less maintenance and its self-starting capability. However, the limitation of SRM is its high torque ripple because of its nonlinear characteristics. The performance of a switched reluctance motor with various DC –DC converters is analysed in this work and the results are compared in terms of the speed of the motor and its torque ripple percentage. The switching time of the converter is controlled by the MPPT controller, which uses incremental conductance and the Integrator method. The converters presented in this work are the Boost converter and the Cuk converter. These two types of converters are designed in MATLAB software and their characteristics are analysed while supplying the switched reluctance motor. The suitability of the proposed system with the motor is analysed by simulation results. From the results, it is confirmed that the performance of the Solar PV fed Switched reluctance motor is improved in terms of speed and torque ripple by implementing this type of converter. Hence, it is suitable for electric vehicle applications, which require less torque ripple and mechanical vibrations.

A Systematic Approach to Synthesize a Non-Isolated TPCC With Fully Reconfigurable Structure for RES

This brief presents topology synthesis and control of a non-isolated three-port DC-DC Cuk converter (NI-TPCC) to integrate a solar photovoltaic (PV)-battery system. The NI-TPCC topology is fully reconfigurable with bidirectional power flow between any two ports. This feature enables the NI-TPCC to operate in different operating modes named as single input dual output (SIDO), dual input single output (DISO), PV to load (P2L), PV to battery (P2B) and battery to load (B2L). The operating principle, modeling, small-signal analysis, and mode selection of the converter are presented in this brief. An automatic mode selection (AMS) based PI-lead controller is designed to control the voltages and currents of three ports during the transition from one operating mode to another. The effectiveness of the proposed control algorithm during all operating modes is verified in a 200W laboratory prototype of NI-TPCC.

Sliding-Mode Control Techniques of SEPIC Converter in Continuous Current Mode

Nowadays, direct current (DC) voltage is required for the operation of the machines used in many industrial applications. DC voltage generating photovoltaic (PV) panels or other DC voltage generators need to be converted from the voltage level produced by the DC voltage levels required for the operation of the machines. The conversion of a DC voltage to a different DC voltage is performed by DC-DC converters. The most commonly used DC-DC converters in the literature are buck, boost, buck-boost, CUK and SEPIC converter. In this study, different control methods are used in order to reach the desired voltage level of the output voltage of the equivalent series resistance and ideal SEPIC converter in continuous current mode. Conventional Proportional-Integral (PI) and Sliding Mode Control (SMC) methods are used to ensure that the converter reaches the desired voltage level. PI controller parameter values are calculated according to trial and error method. In order to compare the performances of the controller used in the case ideal and equivalent series resistance cases, the controller parameters are taken the same. SMC is shown to perform better in ideal and equivalent series resistance SEPIC converter compared to the traditional PI controller from simulation results. Besides, modeling and controller applications of SEPIC converter are realized by using MATLAB / SIMULINK program.

High Hybrid Power Converter Performance Using Modern-Optimization-Methods-Based PWM Strategy

Recently, interest in DC networks and converters has increased due to the high number of applications in renewable energy systems. Consequently, the importance of improving the efficiency of the hybrid converters has been highlighted. An optimal control strategy is a significant solution to handle the challenges of controlling the hybrid interleaved boost–Cuk converter. In this article, a modern-optimization-methods-based PWM strategy for a hybrid power converter is developed. In order to improve the performance of the hybrid converter, four modern optimization algorithms—namely, Manta ray foraging optimization (MRFO), Marine Predators Algorithm (MPA), Jellyfish Search Optimizer (JS), and Equilibrium Optimizer (EO)—are employed to minimize the input current ripple under different operation scenarios. The results of the proposed modern optimization algorithms have shown more efficient converter performance and balanced power-sharing compared with conventional strategies and the literature on optimization algorithms such as Differential Evolution (DE) and Particle Swarm Optimization (PSO). In addition, the results of all operation cases presenting the proposed optimal strategy successfully reduced the input current ripple and improve the performance of power-sharing at the converter compared with the conventional methods.

Novel soft-switching integrated various converter of ZVT-ZCT grid connected PV system

Solar photovoltaic systems contribute to the development of the world's most environmentally sustainable and cost-effective electrical energy. High-power inverters commonly use a technique known as three-level design to increase their performance by soft-switching. On the other hand, the switching action is stressed in normal operation because the current or voltage will not be zero at the time of the transition. For CUK, SEPIC, ZETA and CASCODE converters operating in critical switch mode, it has been proposed that a new type of DC-DC converters primarily formed on capacitive coupling DC-DC converters be developed. The proposed converters are zero-current-voltage-switching half-square-quarter-wave converters with a zero-current auxiliary circuit. LC-circuit resonance causes power switches to turn on at zero voltage, getting rid of the switching losses during turn on. The hybrid Incremental Conductance & Integral Regulator technique is used to track MPP available from PV system. The proposed converter's results and efficiency are compared to those of traditional semi-square-quarter-wave zero-current-converter converters. The proposed converters achieved power efficiencies of 98.7% in the step-up mode and 98.8% in the step-down mode for the rated load state, respectively. The proposed CUK, SEPIC, ZETA and CASCODE Converters Simulation are implemented in the MATLAB Simulink programme to validate its efficiency.

High step‐up combined boost‐Cuk converter with switched‐inductor

In this paper, a novel boost-Cuk converter topology based on the combination of a boost and Cuk converters is proposed. The converter has the characteristics of boost and Cuk converters, voltage gain is improved, and the input and output current of the converter is continuous. To further enhance the voltage gain, switching inductance technology is introduced. The proposed converter is designed using magnetic integration, and the influence of magnetic coupling technology on inductance current ripple is theoretically investigated to obtain the converter's minimum inductance current ripple design. A prototype is realised to confirm the validity of the theoretical analysis and the operation of the proposed converter.

A Simple Yet Fully Adaptive PSO Algorithm for Global Peak Tracking of Photovoltaic Array Under Partial Shading Conditions

This article proposes a simple yet fully adaptive particle swarm optimization (PSO) algorithm to find the global peak (GP) of a photovoltaic array under partial shading condition. It exploits a constrained optimization approach having a very simple PSO structure with two adaptive parameters. The first one that controls the magnitude of velocity is adaptively varied according to the absolute distance of each particle with respect to best particle's position. The other parameter controls the search space, has been varied based on a penalty condition that decides the participation of particle in the next iteration. Regardless of a wide range of population size, the proposed scheme precisely locates the GP without jeopardizing the tracking speed—consumes a maximum of 16 perturbations. The algorithm is implemented on a Cuk converter and compared to two well-known tracking methods. It is also validated through run length distribution (RLD) test. The obtained RLD results reveal that proposed PSO outperforms other two methods, in terms of convergence speed and success rate. It always obtains 100% rate by utilizing fewer perturbations of voltage. When tested for a whole day environmental profile, the average efficiency of proposed algorithm is found to be 99.65%.

Performance Analysis of Buck Boost and Cuk converters for Solar PV Applications using PI controller and Fuzzy Logic Controller

Abstract: In this paper, analysis of DC-DC converters Buck-Boost and Cuk converter by using PI Controller and Fuzzy Logic controller. These converters are mainly used in solar PV applications and it is explained. In this paper mainly MATLAB/ Simulink software is used for the compare the performance of both. the design is mainly compared with the proportional integrated controller versus FLC. The main objective of this work to reduce the overshoot of these types of converters. The buck boost and cuk converter are simulated for different Loads and their output voltage is settle at desired voltage The performance of buck-boost and cuk converter are simulated using Matlab/Simulink and comparison study is performed. The complete control system has been developed analysed and validation by the simulation. Keywords: Buck-Boost Converter, Cuk Converter, MATLAB/ Simulink, Solar PV and Fuzzy Logic Converter

A Power Quality Improved EV Charger by Using Bridgeless CUK Converter

Abstract: This study designs and develops an improved bridgeless (BL) Cuk converter-based electric vehicle (EV) battery charger with a high-power factor and higher efficiency. It offers a low-cost, high-power-density-based charging solution for EVs. This charger has fewer components functioning during a single switching cycle, which decreases the extra conduction loss experienced by the typical charger's diode bridge rectifier. As a result, it boosts the charger's efficiency. The suggested topology also avoids the undesired capacitive coupling loop and unwanted conduction via the body diode of the inactive switch in the previously developed BL Cuk converter. This considerably enhances the charger's efficiency. A flyback converter synchronises the orders for constant current and constant voltage charging. The suggested charger draws a sinusoidal current from an alternating current main, and the overall harmonic distortion in the supply current is kept within the IEC 61000-3-2 requirements. The suggested charger's increased efficiency and power quality indices are studied to verify its good charging performance under all operational situations. Keywords: Bridgeless (BL) Cuk converter, discontinuous conduction mode (DCM), flyback converter, power factor correction (PFC), and power quality are all terms used to describe a battery charger (PQ).

Optimal Control of Active Cell Balancing for Lithium-Ion Battery Pack With Constraints on Cells’ Current and Temperature

Abstract Cell balancing control for Li-ion battery pack plays an important role in the battery management system. It contributes to maintaining the maximum usable capacity, extending the cycle life of cells, and preventing overheating and thermal runaway during operation. This paper presents an optimal control of active cell balancing for serially connected battery pack that maintains the cell’s current and temperature in a suitable range during the equalizing process. Using the cell-to-cell balancing circuit based on CuK converter for two adjacent cells, the state of charge (SoC) and temperature dynamic of cells in the pack are modeled. Then, the optimal control problem for active cell balancing is established with constraints on cells’ current and temperature. The solution of this nonlinear optimal problem solved using sequential quadratic programming (SQP) is the optimal duty fed to the cell balancing circuits. The experimental test is applied to the battery pack of seven Samsung cells connected in series, and the reliable and efficient results show that the cell balancing process takes place shortly and adaptively depending on the discharge/charge current of the pack, the desired temperature increasing limit, and technical constraints of balancing circuits.

РОЗРАХУНОК ПЕРЕТВОРЮВАЧА КУКА ЗА ДОПОМОГОЮ МЕТОДА УСЕРЕДНЕННЯ НА ОСНОВІ ТЕОРЕМ ЛАГРАНЖА

A mathematical model of the Cuk converter has been developed using the state-space averaging method based on La-grange theorems for the mode of continuous currents and voltages at storage reactive elements. Analytical expressions are obtained based on relative variables, making it possible to calculate processes in the converter in a wide range of parame-ters at the control zone of the duration of switching intervals. The limiting dependences of converter parameters between the modes of discontinuous and continuous currents and voltages in storage elements are calculated to determine the effec-tive modes of operation of the device. Analytical dependencies are obtained, making it possible to determine the maximum values of currents and voltages in the elements of the converter over the entire switching range and allowing choosing these elements of the device with acceptable parameters at the stage of its design. Ref. 14, fig 5, table.

Non-Isolated DC-DC Converters in Fuel Cell Applications: Thermal Analysis and Reliability Comparison

An alternative energy source that has appeared beyond expectations and has seen a lot of progress is the fuel cell. A proton exchange membrane (PEM) fuel cell is chosen for analysis and requires a DC-DC boost converter as an interface between the fuel cell and the load to provide a high-gain regulated voltage. Although great effort towards developing different converter topologies has been made during recent decades, less attention has been devoted to the reliability and thermal performance assessment of the present converters. In this paper, five non-isolated DC-DC converters are analyzed in terms of both thermal behavior and reliability. The temperature estimation of semiconductor devices as a critical part of the thermal analysis has been made via a detailed thermal model and the reliability is evaluated by means of a power cycling test. Finally, a performance score has been attributed using the TOPSIS ranking methodology and considering all the criteria (e.g., the number of components and cost) at the same time. The results indicated that the floating interleaved boost converter is always at the top of the list, even if the weight of the indicators is changed. When the weight of the cost criterion is higher than the reliability criterion, the multi-switch boost converter will be in second place. If the weight of the reliability criterion is greater than cost, the interleaved and multi-switch converter are ranked second and third, respectively. Additionally, the Cuk converter with a closeness coefficient of zero is always associated with the most unfavorable performance.

Novel Single-Phase Cuk-Derived Bridgeless PFC Converter for On-Board EV Charger With Reduced Number of Components

This article proposes a novel single-phase bridgeless Cuk-derived power factor corrected (PFC) converter with reduced component count for on-board EV charging application. The unique feature of this proposal is to design and operate the output inductor of the converter in discontinuous current mode for the complete power range to attain PFC naturally at ac mains, thereby not requiring the input voltage and input current sensing, which reduces the converter cost, and improves the power density as well as converter robustness to high-frequency noise. The converter control is very simple in operation and easy in implementation with only a single sensor-based voltage control loop. The semiconductor components voltage stress of the proposed power converter is lower when compared to the traditional Cuk converter. The simulation results from PSIM 11 and experimental results are given by testing a proof-of-concept hardware laboratory prototype to demonstrate the high performance of PFC operation of the proposed converter.

Performance Evaluation of Solar-PV-Based Non-Isolated Switched-Inductor and Switched-Capacitor High-Step-Up Cuk Converter

Solar photovoltaic (PV) is the most promising renewable energy source available on Earth. Three topologies based on a switched-inductor capacitor and non-isolated high-step-up Cuk converter have been proposed for solar PV. These topologies of the Cuk converter have higher boosting ability than conventional Cuk and boost converters and can reduce the voltage stress of the main switch. A small voltage rating and on-state resistance can give higher efficiency of the converter. The voltage boosting ability of all three topologies was compared to each other and with a conventional Cuk converter. The boosting capability of the third converter was 11 times at 0.75 duty cycle with a solar PV source. These converters do not use a coupled inductor and transformer, which leads to less volume, reducing coupling/core saturation loss, and thus the cost of the converter. A solar PV system of 12 volts was used for boosting with these converters for analysis of the feasibility of use with renewables. The three topologies of the switched-inductor and switched-capacitor (SLSC) Cuk converter were designed and simulated in MATLAB/Simulink to evaluate their effectiveness.

MPPT using Firefly Algorithm for Cuk Converter in Photovoltaic

High intensity of sunlight in Indonesia (up to 10 hours per day) is a great opportunity to be utilized as renewable energy by absorbing solar energy using solar panels. The absorbed solar energy is channeled into a DC/DC converter circuit with a Cuk converter topology so that it can be used with small current ripples. The Maximum Power Point Tracker (MPPT) method is needed to get optimum power from solar panels. To optimize the MPPT value, its performance is supported by using the Firefly Algorithm (FFA). This study focused on observing changes in FFA parameters, i.e., firefly populations and random parameters to generate optimal power on Cuk converter topology with MPPT method. FFA embedded in microcontrollers has successfully optimized MPPT performance with the best response obtained in the firefly population = 25, absorption coefficient (γ) = 0.5, random value (α) = 0.6, iteration = 10, with an optimal power of 25.7 Watts.

Topology synthesis and control of integrated three-port converter for renewable energy system

This paper presents topology synthesis and control of a non-isolated three-port dc-dc Cuk converter (TPCC) for a renewable energy system (RES). The proposed control structure is composed of a decoupling network to address the inevitable cross-coupling effect of multiport converters present due to various interacting control loops. In addition, a PI-lead compensator is designed to achieve improved steady-state and transient performance in each operating mode of TPCC. Furthermore, an autonomous mode selection (AMS) technique is proposed to achieve a seamless transition between different operating modes. The AMS technique automatically shifts the operating modes of TPCC by comparing the available instantaneous power at each port to maintain an uninterruptable power supply to the load. Moreover, a state-space averaging method is adopted for modeling different operating modes and transfer functions of TPCC. Finally, the feasibility and effectiveness of the proposed control algorithm are validated with the help of a laboratory prototype.

Improvement of Single-Switch Bridgeless PFC Cuk Converter for Circulating Current Elimination and Components Maximum Current Stress Reduction

This paper presents the improvement of single-switch bridgeless PFC Cuk converter for circulating current elimination and maximum current stress reduction on components. On the existing converter structure, circulating current at diodes causes conduction losses and maximum current stress that increase the component size. Therefore, circulating current is eliminated by rearranging the position of input diodes thus the input diodes in which can block the returning path of current through the input inductors. The principle of circulating current elimination is also discussed in detail in this paper. A 100 W converter with output voltage of -48 V has been tested to verify the principle. The results of the experimental hardware show the removal of the circulating current, the maximum current stress in input diodes are reduced from 8 A to 2.8 A and the maximum current stress in input capacitors also reduced from 10.3 A to 6.5 A.

An Isolated Bridgeless Cuk–SEPIC Converter-Fed Electric Vehicle Charger

A single-stage electric vehicle (EV) battery charger with an isolated bridgeless (BL) Cuk–single-ended primary-inductor converter (SEPIC) converter is developed in this article. The design of proposed charger is ensured in discontinuous conduction mode with intrinsic power factor correction (PFC) at ac mains. Compared to the BL Cuk converter topology when used for both positive and negative cycles, the proposed topology has reduced number of components with improved efficiency. This is due to integration of Cuk and SEPIC converters during the individual half cycle. The presence of output inductor at Cuk converter side also smoothens the output current, as compared to SEPIC converter used for both cycles. A high power quality (PQ) operation of new BL isolated PFC converter with an EV battery load of 48 V/100 Ah is verified using single-phase PQ analyzer. A laboratory prototype of proposed charger is developed and validated to corroborate the efficient performance during two charging profiles. Test results are shown under steady state as well as over extreme load and line conditions. Different performance indices such as displacement PF, ac mains PF, and mains current distortion are recorded, which comply the IEC 61000-3-2 standard.