Performance Of Converter Research Articles

Modelling of Bi-Directional Buck-Boost Converter for Electric Vehicle

Abstract: The rapid growth of electric vehicles (EVs) has necessitated the development of efficient and versatile energy storage systems. In this study, we present the modelling and implementation of a switching bi-directional buck-boost converter based on electric vehicle hybrid energy storage. The proposed converter offers a flexible and reliable solution for managing energy flow between different storage elements in an EV, such as batteries and ultra-capacitors. First, a comprehensive mathematical model of the converter is developed, taking into account the dynamic behaviour of the energy storage components. This model enables us to analyse and optimize the converter's performance in terms of efficiency, voltage regulation, and power delivery capabilities. Furthermore, simulation studies are conducted to validate the accuracy of the model and assess the converter's performance under various operating conditions. Based on the modelling and simulation results, a practical implementation of the converter is carried out using high-quality electronic components. The design considerations, including component selection, circuit layout, and control strategy, are discussed in detail. The implemented converter is then evaluated experimentally to validate its performance and verify the effectiveness of the proposed modelling approach. The results demonstrate that the switching bidirectional buck-boost converter effectively manages the energy flow between the different storage elements in the hybrid energy storage system. It achieves high conversion efficiency, voltage regulation, and power transfer capabilities, enhancing the overall performance and range of electric vehicles. The developed model and implementation provide valuable insights for the design and optimization of similar converter topologies for electric vehicle applications. Overall, this study contributes to the advancement of energy storage systems in electric vehicles, facilitating the adoption of sustainable and efficient transportation solutions in the future

Implementing the Venturini Modulation technique for controlling an AC/AC Matrix Converter

These abstract focuses on the implementation of the Venturini modulation technique for controlling a three-phase matrix converter. The Venturini modulation technique is a widely adopted method in the field of power electronics, utilized to achieve precise control over the operation and performance of converters. In this particular application, the technique is employed to regulate and optimize a three-phase matrix converter's functionality. The three-phase matrix converter serves as a specialized power electronic device responsible for converting electrical energy between three-phase systems with varying voltage and frequency. By implementing the Venturini modulation technique, the converter's operation can be optimized, ensuring efficient power conversion and optimal utilization of its resources. The Venturini modulation technique enables the converter to accurately control the output voltage and frequency, resulting in improved power quality and enhanced overall system performance. To implement this technique, specific control algorithms and strategies are employed, allowing the converter to dynamically adjust the switching patterns of its semiconductor switches, thereby generating the desired output waveform. In summary, the implementation of the Venturini modulation technique for controlling a three-phase matrix converter is a vital step in optimizing power conversion, improving power quality, and enhancing overall system performance. This abstract highlight the importance of this implementation and its potential impact on power electronics and electrical systems in diverse applications.

An Extended-State Observer Based on Smooth Super-Twisting Sliding-Mode Controller for DC-DC Buck Converters

This paper designs a novel smooth super-twisting extended-state observer (SSTESO)-based smooth super-twisting sliding-mode control (SSTSMC) scheme to promote the robust ability and voltage-tracking performance of DC-DC buck converters. First, an SSTESO is proposed to estimate the unknown lumped disturbance and compensate for the estimation of the voltage controller. The SSTESO is realized by constructing a novel smooth function to replace the nonlinear sign function in STESO, which can provide a faster convergence speed and higher estimation accuracy. The SSTSM controller is designed by adopting a similar smooth function to further suppress chattering and improve dynamic response. Comprehensive simulation results demonstrate that the proposed SSTESO-based SSTSMC scheme can improve the robustness and transient response of a DC-DC buck converter system in the presence of external disturbance and parameter uncertainties.

Battery loss prediction using various loss models: A case study for a residential building

This work compares and quantifies the annual losses for three battery system loss representations in a case study for a residential building with solar photovoltaic (PV). Two loss representations consider the varying operating conditions and use the measured performance of battery power electronic converters (PECs) but differ in using either a constant or current-dependent internal battery cell resistance. The third representation is load-independent and uses a (fixed) round trip efficiency. The work uses sub-hourly measurements of the load and PV profiles and includes the results from varying PV and battery size combinations. The results reveal an inadequacy of using a constant battery internal resistance and quantify the annual loss discrepancy to −38.6%, compared to a case with current-dependent internal resistance. The results also show the flaw of modelling the battery system’s efficiency with a fixed round trip efficiency, with loss discrepancy variation between −5 to 17% depending on the scenario. Furthermore, the necessity of accounting for the cell’s loss is highlighted, and its dependence on converter loading is quantified.

A Comprehensive Small-Signal Model Formulation and Analysis for the Quasi-Y Impedance-Source Inverter

This paper presents a detailed derivation of the small-signal model and components design considerations for the Quasi-Y-Source inverter. The design methodology is based on the converter steady-state operation, considering the impedance network inductor and capacitor voltage and charge balances, respectively. Moreover, the additional design criteria for component selection, considering control constraints and performance compromise, are given by parametric variation analysis based on converter dynamic response. The small-signal model and transfer functions are obtained using a state-space averaged model, including converter non-ideal characteristics given by equivalent-series resistances (ESR), which makes possible the proposition of different control strategies, using both single or multi-loop schemes. To demonstrate the usefulness of the proposed small-signal model, a DSP-based single-loop type-II PI control strategy is used in which the peak DC-link voltage is indirectly controlled through the measurement of the impedance network capacitor voltage. The controller and converter performances are verified with simulation and experimental results and successfully confirm the validity of the proposed dynamic model. Finally, the obtained results are validated with a built small-scale three-phase/three-wire inverter prototype.

The improved 2DoFs-PLL for MMC-HVDC transmission system

The performance of a modular multilevel converter (MMC) is highly related to the three-phase phase-locked loop (PLL). The presence of the DC component, the harmonic component, and the negative sequence component results in the poor dynamic and steady-state performance of the PLL, such as fundamental frequency oscillations in the phase estimated by the PLL. In order to suppress the influence of parameters variation and disturbance of the three-phase grid voltage, an improved PLL with a moving average filter with two degrees of freedom PID (2DoFs-PID) is proposed. Moreover, to improve the phase margin and gain margin, an extra compensator with a pole and a zero is introduced into the 2DoFs-PLL. The improved 2DoFs-PLL can track the frequency and phase with superior accuracy, stability, and rapidity. Furthermore, the methodology for the parameters design of the 2DoFs PID controller is introduced, based on the index of integrated time and absolute error. A simulated model and experimental platform are established to verify the performance of the improved 2DoFs-PLL. The results show that the improved 2DoFs-PLL can meet the needs of both steady-state performance and dynamic performance by employing the 2DoFs-PID controllers.

Retracted: Copper Oxide Nanoparticles Incorporated in the Metal Mesh Used to Enhance the Heat Transfer Performance of the Catalytic Converter and to Reduce Emission

Retracted: Copper Oxide Nanoparticles Incorporated in the Metal Mesh Used to Enhance the Heat Transfer Performance of the Catalytic Converter and to Reduce Emission

How bending deformation affects the performance of polarization converters based on slot waveguides

Polarization is an important characteristic of light and plays a critical role in many natural and industrial processes. In this paper, we present an optical gradient force actuated polarization converter based on a slot waveguide, which can convert linearly polarized light into circularly polarized light. The working principle of the presented polarization converter is that optical gradient forces deform the slot waveguide to adjust its birefringence, thus yielding a desired phase shift between two orthogonal components of light. An optomechanical model with all possible mechanical boundaries is developed to solve the bending deformation of polarization converters. The effective index method and dispersion relation method are used for the calculation of birefringence and optical gradient forces, respectively. The influences of the width of waveguides and the initial width of the slot on the working performance of polarization converters are discussed. It is found that these influences are independent of the mechanical boundaries. An empirical formula for describing the relation between the working power and length of polarization converters is given. This empirical formula may be helpful when designing such polarization converters.

Design and Analysis of a Battery Charging System for a Pico-Hydro Power Plant

Pico-Hydro Power Plant (PLTPH) is very dependent on the received water energy, therefore a storage medium is needed to store electrical energy by using a battery and DC-DC Buck Converter as a regulator of the output voltage of the generator to charging the battery. In addition, it is necessary to design equipment in battery charging system. At PLTPH to adjust the generator voltage using a DC-DC Buck Converter 30A with an input voltage rating of 20V-70V and an output voltage of 2.5V-50V can be set for charging the battery. The battery capacity of this PLTPH uses 4 VRLA 12V 100Ah batteries which are arranged in 2 series and 1 parallel so that the battery capacity becomes 24V 200Ah with a load of the main PPYD Al-Ikhlas building with 4.2kWh of energy consumed. In testing the performance of the battery the battery is in accordance with the characteristics of the battery and the voltage is inversely proportional to the current, while the DC-DC Buck Converter has a large efficiency of 85% which shows the performance of the DC-DC Buck Converter is very good

A coordinated control scheme for VSC-MTDC system with multiple renewable energy sites based on voltage margin and adaptive drooping control

This paper designs a novel coordinated control scheme to improve the control performance of voltage source converters (VSC) based multi-terminal high voltage direct current (MTDC) transmission network by merging the benefits of adaptive drooping and voltage margin controllers. In this proposed scheme, the droop coefficient is used to manage the DC voltage and maintain power sharing by shifting the control modes of the rectifiers and inverters in the presence of considerable power disturbances. The droop coefficient is planned based on the stability limit of DC voltage. The performance of the designed control scheme is compared to that of existing coordinated control and voltage margin droop control approaches. A ±400 kV five-terminal VSC-MTDC network is developed in PSCAD to verify the planned control method. The simulation results indicate that the proposed control scheme can achieve good performance for controlling the DC voltage and maintaining active power in the MTDC system.

A bidirectional single‐phase Z‐source AC‐AC converter with reduced voltage stress on switches and safe commutation strategy

SummaryIn this paper, a bidirectional single‐phase Z‐source ac‐ac converter is proposed. Common features between the proposed converter and its counterparts are the capability of boost in‐phase, buck out‐of‐phase, and common ground. The output voltage gain of the proposed converter is improved compared with previous Z‐source ac‐ac converters, while the total standing voltage (TSV) of the switches has also been significantly reduced. Owing to the reduction of voltage stress of semiconductor elements, the switching device power (SDP) of the proposed converter is reduced. As a result, the cost of the converter is also reduced. A bidirectional switch is replaced instead of the output filter inductor to reduce the volume and weight of the converter. A safe commutation strategy is applied to eliminate voltage spikes on switches. Furthermore, the proposed converter can transfer power in both directions. By evaluating the converter in different operating modes, the key relationships and parametric design of the converter are presented. A laboratory prototype is made to confirm the proposed converter performance.

A single-phase direct buck-boost AC–AC converter with minimum number of components

In this paper, a single-phase direct pulse width modulation (PWM) buck-boost AC–AC converter is proposed. The proposed converter utilizes a minimum number of semiconductor switches and passive components that decreases the converter power losses and offers high efficiency. It can be operated with simple PWM control and doesn’t require soft-commutation strategies. It does not suffer from input source shoot-through and commutation problems. Moreover, it supplies both continuous input and output currents. The common sharing ground of the input and output gives the proposed converter the feature that it can be utilized for voltage sag and swell compensation. A comparison of the proposed converter performance with similar existing converters is presented. Also, detailed circuit analysis, component design guidelines, and simulation results using the MATLAB/Simulink environment are demonstrated. A laboratory prototype has been built and tested to validate the converter performance and confirm the results obtained by computer simulation.

A Class-E-Based Multichannel Auxiliary Power Supply With Individual Hysteresis Control

A high performance auxiliary power supply (APS) with multiple isolated outputs plays a crucial role in ensuring the effective operation of power converter systems. An isolated resonant current source converter is usually adopted as the APS in medium-voltage (MV) applications with the advantages of low coupling capacitance and high insulation strength. In this paper, a Class E-based multichannel APS, featuring a low component count, modular circuit structure and ease of scalability to multiple output channels, is proposed. The operation principle of the proposed circuit is presented in detail. To overcome the cross-regulation problem in multiple outputs, an individual hysteresis control approach is introduced to regulate each output separately and decouple the multiple outputs. The converter performance under open/short-circuit fault conditions is also explored with the proposed control scheme. Design considerations, including the zero-voltage-switching (ZVS) realization and the output power capabilities, are presented, together with a step-by-step parameter design approach. Finally, an 8 output APS experimental prototype (with different output voltage levels) is presented. The experimental results demonstrate the output voltage decoupled regulation and load independent ZVS performance of the prototype.

Resiliency Enhancement Control of Converter Fed Smart Renewable Micro Grids Against Multiple Risks

Increasing the penetration level of converter-based renewable power plants, along with the advanced grid code requirements, has made the role of the control of grid-connected voltage source converters more important. In this paper, an improved combined control method for the grid-connected converters is proposed to improve the resiliency of the microgrid against multiple risks. Two main objectives of the proposed method are to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i)</i> improve the steady state and dynamic performance of grid-connected converter, and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ii)</i> enhance the resiliency of the system. It copes with high power fluctuations, severe load changes, symmetrical and asymmetrical short circuit faults, and unbalanced grid conditions. As a result, no extra means are needed to tackle each undesirable conditions. The advantages of a current control scheme are integrated with a logical switching table in the proposed control method to improve its steady state and dynamic performance. The virtual flux estimation is eliminated from the control system to reduce the dependency of the system on the parameters. It provides stable operation under normal and abnormal conditions such as unbalanced voltages, voltage sag, faults, etc. The performance of the proposed control method is compared with a virtual-based direct power control and a conventional combined control to confirm its effectiveness superiority through simulation and experimental results.

Axisymmetric reflectors in wave energy converter arrays: Harnessing scattering to increase energy extraction

We elucidate the effect of non-extracting reflectors on the performance of wave energy converter (WEC) arrays. We consider an infinitely periodic row of converters parallel to an infinitely periodic row of discrete axisymmetric reflectors (C-R arrays), and we study how the spatial configuration affects energy extraction. Using a multiple-scattering algorithm for linear wave-array interactions, we conduct a series of simulations of C-R arrays for a range of spatial configuration parameters, wavenumbers, and wave incident angles. We find that C-R arrays can significantly increase energy extraction compared to a WEC array by itself. We offer a simplified theoretical model, based on the far-field response of periodic rows in isolation, which shows that the large increases in energy extraction result from the constructive Bragg and Laue interferences caused by wave interactions with the reflector row. For the pertinent case of incident waves of the WEC-resonant frequency, we find that optimized C-R arrays can achieve energy extraction gains of O(500%). Remarkably, the optimal C-R array extracts more energy than two rows of converters of optimal configuration even though the C-R array consists of only half as many WECs.

高周波IH応用単相ダイレクトAC-ACコンバータの固定周波数電力制御手法

The direct ac-ac converter is an effective circuit topology for high-efficient power conversion in induction heating (IH) applications. The conventional pulse frequency modulation (PFM)-based power control scheme causes audible noises between the adjacent IH loads which operate at different switching frequencies. As a solution for the technical issue, a new fixed-frequency power control methodology for a single-phase direct ac-ac converter is proposed in this paper, featuring a wide range of soft switching operation and robustness for abnormal load conditions. The principle of the proposed pulse modulation is explained in detail with the logic circuit diagram of controller. The performances of the ac-ac converter and power controller are demonstrated by simulation, after which the effectiveness is revealed in terms of the power control range and soft switching operation.

Hydrodynamic Performance and Power Absorption of A Coaxial Double-Buoy Wave Energy Converter

Hydrodynamic Performance and Power Absorption of A Coaxial Double-Buoy Wave Energy Converter

High-performance Cuk converter with turn-on switching at zero voltage and zero current

The soft-switching technique has the potential to significantly enhance the performance of the power converter. This is primarily because it allows for an increase in the switching frequency, which ultimately leads to improved modulation quality. This raises extra concerns, particularly in high-power applications, because in a standard hard-switching converter structure, components can often not function at frequencies higher than a few hundred hertz. This paper presents a high-efficiency soft switching CUK converter.When the main and auxiliary switches are turned on and off at zero voltage, the proposed converter yields zero voltage and zero current. The suggested method is ideal for a DC-DC converter based on IGBTs or MOSFETs. The recommended systems are described using theoretical analysis, the results of computer simulations, and experimental data derived from a prototype. The design parameters of the inductance and capacitor circuit for edge-resonant soft switching were obtained using the output power and the switching duty ratio. In the end, soft-switching is better than hard-switching in terms of efficiency, particularly when operating under full load.

Sliding mode controller for multiphase bidirectional flyback converter topology in hybrid electric vehicle applications

Day by day, the power electronics (PE) application is increasing in hybrid electric vehicles (EV). The power interfacing between the DC link drive and battery is the main issue of EVs. The best choice for this application is the bidirectional flyback converter (BFC). This can be used in a different interface, like load from the grid to the battery, external Genset to the battery, and battery to the load. In this work, a Multiphase BFC Topology is developed for Hybrid EVs. It includes the design of the Sliding mode controller (SMC), which offers superior performance to the existing controller. Due to its separated nature and smaller machinery, it is most favoured in high-voltage applications. The suggested work is executed in MATLAB/Simulink environment. The proposed method is compared with the current controllers like GA-PID, Fuzzy logic controller (FLC). From the experimental outcomes, it is observed that the proposed SMC technique gives better converter performance.

Increasing PEM fuel cell performance via fuzzy-logic controlled cascaded DC-DC boost converter

The voltage level produced by Proton Exchange Membrane (PEM) fuel cell (FC), which is one of the clean energy sources, is low for many industrial applications. For this reason, for many industrial applications such as electric vehicles, it is necessary to use a boost type DC-DC power electronic circuit at the output of PEM FC. In this case, in addition to the PEM FC performance, the dynamic performance and efficiency of the DC-DC converter to be used affect the performance and efficiency of the total system. In this study, a single-switch cascaded DC-DC boost converter, which has both higher voltage gain and more efficiency compared to conventional cascade converter and other boost type converters, is proposed for PEM FC. Since the proposed single-switch cascaded DC-DC boost converter includes only one controlled-switch, it is efficient as well as smaller in size and less costly compared to the other types. In addition, the proposed single-switch cascaded DC-DC boost converter is tested with the traditional PID and fuzzy-logic control methods to observe the dynamic performance of PEM FC. When the fuzzy logic controller is compared with the PID controller, it is clearly seen that it gives 21% more successful results as per rise time, 71% settling time, 97% overshoot, and 26% RMSE (Root Mean Square Error) error rate. As a result, when the proposed single-switch cascaded DC-DC boost converter is regulated via fuzzy control method, a more efficient PEM FC system which has better dynamic performance can be designed.