Buck Inverter Research Articles

Research on controlling dual buck inverter in sliding mode based on buffered inductor

Abstract To overcome the problems of power transistor passthrough and switching loss in traditional bridge inverters, it is suggested to replace the conventional double Buck inverter with a double Buck inverter that has a buffer inductor placed in the center of the bridge arm with one that has a very modest inductance value. Firstly, a dual inductor single structure of the Buck inverter was examined, and based on this, a dual Buck inverter topology structure based on a buffer inductor was proposed. Then, the application of the sliding mode control strategy in dual Buck inverters based on buffer inductance was elaborated. Ultimately, tests were conducted to confirm the accuracy of the theoretical theory. The proposed dual Buck inverter based on buffer inductance solves the problem of low inductance utilization while retaining high reliability. Compared with single inductance DBI, it has smaller losses and lower control complexity, which has practical application value.

A Comprehensive Review of dc/ac Single-Phase Differential-Mode Inverters for Low-Power Applications

Switched-mode power supplies (SMPSs) are single-switch, two-state, dc/dc power electronic converters and can be generally classified into buck, boost, and buck–boost converters according to voltage transfer functions. There are more than 33 SMPSs with different characteristics in terms of their current and voltage ripples, voltage and current stresses, and their being voltage/current sourced. Although they are usually employed in the dc/dc mode, these SMPSs can be connected differentially to operate as single- and three-phase dc/ac inverters; hence, they are used in low-power applications. The resultant inverters will behave differently according to the topologies that they are descendant from. Several publications have presented differential-mode single-phase inverters (DMSIs) for low-power applications, focusing on their suitability for renewable energy systems. These proposals have mainly focused on boost and buck–boost configurations, with less focus on the buck inverter topologies. Also, several possible configurations for other DMSIs have not yet been proposed or discussed. This paper proposes a comprehensive review of the different possible configurations of the DMSIs, illustrating a systematic method by which to generate and explore them. The paper will mainly categorize the DMSIs in terms of their voltage transfer function and will then discuss the topologies, presenting the main advantages and disadvantages of each one.

Power quality conditioning using two-level buck inverter based DSTATCOM

A two-level buck inverter is derived from the voltage source inverter, by replacing the additional power devices and suitable combination of inductor circuits respectively. Novel isolated buck inverter, featuring each-phase conversion and soft-switching within wide operation range, is developed. An optimized control strategy is employed to realize isolated buck conversion. By utilizing the buck inverter, the voltage stress on the power devices and passive components, the self-supported capacitor and filter inductance, is reduced to the half of the output voltage. Moreover, it is proven that the thyristor-controlled series capacitor (TCSC) equipped with a well-designed distributed static compensator (DSTATCOM) can effectively improve source current harmonics reduction, power factor correction in the source side, load compensation, regulation of load voltage and upholding constant voltage across the DC-link capacitor. In order to verify the effectiveness of the proposed DSTATCOM, its performance is compared with the two level DSTATCOM. The extensive simulations are carried out using MATLAB/Simulink to analyze the results. Experimental results using dSPACE-1104 prototype verify the appropriate DSTATCOM.

A New 3-Phase 2-Level Buck Inverter with Switching Loss Improvement

A New 3-Phase 2-Level Buck Inverter with Switching Loss Improvement

Improved 2$$\omega $$ power decoupling in single-phase differential buck inverter for renewable energy applications

Improved 2$$\omega $$ power decoupling in single-phase differential buck inverter for renewable energy applications

Sliding Mode and PI-Based Control for the SISO “Full-Bridge Buck Inverter–DC Motor” System Powered by Renewable Energy

Sliding Mode and PI-Based Control for the SISO “Full-Bridge Buck Inverter–DC Motor” System Powered by Renewable Energy

DC-Bus Ripple Elimination in Single-Phase Grid-Tied Differential Buck Inverter With Reduced Sensor Count

DC-Bus Ripple Elimination in Single-Phase Grid-Tied Differential Buck Inverter With Reduced Sensor Count

Sensorless Tracking Control Based on Sliding Mode for the “Full-Bridge Buck Inverter–DC Motor” System Fed by PV Panel

This paper presents a sliding mode control (SMC) for the “full-bridge Buck inverter–DC motor” system when a photovoltaic (PV) panel is considered as the power supply. The control executes the trajectory tracking task related to the angular velocity of the DC motor shaft without the need for electromechanical sensors. The proposed control is validated through realistic simulation results via Matlab-Simulink. In this regard, the system is constructed by using the electronic components of the specialized power systems library of Simscape. The results of the following four case studies are presented: (i) The performance of the closed-loop system considering two desired angular velocity profiles and three different incident solar irradiance shapes on the PV panel. (ii) An analysis associated with the primary energy source. (iii) A comparison of the proposed SMC versus a passive control. (iv) A study of the current ripple and its relationship with the execution of the tracking control task on the angular velocity.

Analysis of DC/DC Boost Converter–Full-Bridge Buck Inverter System for AC Generation

This paper presents an analysis and simulation of the mathematical model associated to the DC/DC Boost converter–full-bridge Buck inverter system to regulate the voltage output of the DC/DC Boost converter allowing bipolar voltages higher than the input voltage via the full-bridge Buck inverter. To validate the model, the differential flatness property is applied via the flat outputs of the system (energy for the DC/DC Boost converter and the voltage of the full-bridge Buck inverter) considering the complete dynamics, in conjunction with fixed and time-variant trajectory planning. In the simulation results, it is observed that the error signals of the states versus the reference trajectories are acceptable. Regarding the validation of the model, this is performed with open-loop simulations at the circuit level using the SimPowerSystems Toolbox of Matlab-Simulink. The simulation results validate the good performance of the system under study. In this way, the main contribution of this work is that for the first time in the literature, the analysis of a complete dynamics for a conversion system from DC to AC without the use of a transformer and taking advantage of differential flatness is reported; thus, the system analyzed could be represented as an alternative in applications of renewable energies that require conversion from DC to AC.

Robust Flatness-Based Tracking Control for a “Full-Bridge Buck Inverter–DC Motor” System

By developing a robust control strategy based on the differential flatness concept, this paper presents a solution for the bidirectional trajectory tracking task in the “full-bridge Buck inverter–DC motor” system. The robustness of the proposed control is achieved by taking advantage of the differential flatness property related to the mathematical model of the system. The performance of the control, designed via the flatness concept, is verified in two ways. The first is by implementing experimentally the flatness control and proposing different shapes for the desired angular velocity profiles. For this aim, a built prototype of the “full-bridge Buck inverter–DC motor” system, along with Matlab–Simulink and a DS1104 board from dSPACE are used. The second is via simulation results, i.e., by programming the system in closed-loop with the proposed control algorithm through Matlab–Simulink. The experimental and the simulation results are similar, thus demonstrating the effectiveness of the designed robust control even when abrupt electrical variations are considered in the system.

Three-phase modular boost–buck inverter analysis and experimental validation

Three-phase modular boost–buck inverter analysis and experimental validation

Multiharmonic Interaction and Stability Analysis of Two-Stage Double-Input Buck Inverter

Due to stronger nonlinear interaction and coupling effect, multi-input inverters can exhibit a variety of complex oscillations with multiple harmonics. This article develops a multiharmonic modal analysis method to uncover the occurrence reasons of various harmonics in the two-stage double-input Buck inverter. First, a frequency-selective approach is proposed to eliminate the time variance of the nonlinear averaged equations from both line frequency and second harmonic. Second, the nonlinear modal representation of the model obtained here is derived to capture various harmonic interactions and coupling effect from the viewpoint of both fundamental and second-order harmonic characteristics. Third, fundamental harmonic modal analysis is performed with the help of the trajectories of the fundamental modes, and significantly, the occurrence cause of two new harmonic components is explained in detail. And then, second-order harmonic modal analysis is used to discover a series of new nonlinear interacted harmonics, and the influence of these harmonics on different variables is evaluated by the second-order interaction indices. Furthermore, the coupling harmonic analysis is carried out to explore some coupling harmonics. In addition, the stability boundaries for different key parameters and load models are given to improve system stability. Finally, some experimental results are provided to validate the above analysis ones.

Multi-Objective Design of Single-Phase Differential Buck Inverters With Active Power Decoupling

The design of single-phase differential buck inverters has two important considerations, including reducing second-order ripple power using decoupling capacitors and increasing inverter performances. Using larger decoupling capacitors will improve the performance of ripple power reduction and efficiency while reducing power density. Such trade-off has not been fully modeled and investigated, leading to the sub-optimal design of inverters. To address that, in this paper, the trade-off among decoupling capacitance, inverter efficiency and power density are investigated through detailed mathematical modeling and sensitivity study. The trade-off of the volume and power loss of essential inverter components, including power switches, inductors and heatsinks, are also studied to facilitate the inverter design. A fast multi-objective design optimization method based on geometric programming is presented to optimize the inverter efficiency and power density. A 1 kW prototype of a Gallium Nitride (GaN) based inverter has been designed based on the proposed method. A hardware prototype of the inverter has been built and tested, which has an efficiency of 98.02% and power density <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ {4.54\;\mathrm{{kW/dm^{3}}}}$</tex-math></inline-formula> and matches 99% to the presented multi-objective design method. This validates the accuracy and effectiveness of the presented design approach considering detailed trade-off analysis.

A Novel Fundamental Frequency Switching Operation for Conventional VSI to Enable Single-Stage High-Gain Boost Inversion with ANN Tuned QWS Controller

Single-stage high-gain inverters have recently gained much research focus as interfaces for inherent low voltage DC sources such as fuel cells, storage batteries, and solar panels. Many impedance-assisted inverters with different input stage configurations have been presented. To decrease passive component sizes, these inverters operate at high-frequency switching. The high-frequency switching optimizes the passive component sizes but introduces many challenges in the form of high-frequency inductor design, control complexity, high-frequency gate driver requirements, high semiconductor losses, and electromagnetic interferences. This article proposes a novel fundamental frequency switching operation for the conventional voltage source inverters (VSI) to operate as a single-stage high-gain inverter. As the novel operational strategy changes the behavior of conventional VSI from buck inverter to a boost inverter, it is hereafter termed as a novel inverter. By virtue of the operation strategy, switches withstand peak inverse voltage (PIV) equal to DC link voltage, unlike other impedance assisted boost inverters where PIV across switches is the amplified DC voltage. The proposed inverter can invert low-level DC voltage to high voltage AC with low total harmonic distortion (THD) in a single stage without the help of any external filter. A novel quarter-wave symmetric phase-shift controller is proposed for variable voltage and frequency control of proposed inverters tuned by a back-propagation thin-plate-spline neural network (BPTPSNN). Mathematical analysis with experimental validation is presented. Experimentation is carried out on a prototype of 2 kW for single-phase resistive load, induction motor, and non-linear loads.

Sensorless Tracking Control for a “Full-Bridge Buck Inverter–DC Motor” System: Passivity and Flatness-Based Design

A sensorless control based on the exact tracking error dynamics passive output feedback (ETEDPOF) methodology is proposed for executing the angular velocity trajectory tracking task on the “full-bridge Buck inverter–DC motor” system. When such a methodology is applied to the system, the tracking task is achieved by considering only the current sensing and by using some reference trajectories for the system. The reference trajectories are obtained by exploiting the flatness property associated with the mathematical model of the “full-bridge Buck inverter–DC motor” system. Experimental tests are developed for different desired angular velocity trajectories. With the aim of obtaining the experimental results in closed-loop, a “full-bridge Buck inverter–DC motor” prototype, Matlab-Simulink, and a DS1104 board from dSPACE are employed. The experimental results show the effectiveness of the proposed control.

Soft-switching buck inverter

The soft-switching buck inverter, which is mainly applied to solve the contradictions between the switching frequency and the shoot-through problem along with the dead-time effect, is proposed in this paper. A detailed analysis of the relationship between the range of the duty ratio to realize soft-switching as well as the additional voltage stress and the current stress is conducted. In addition, a 1 kW prototype is designed and established. Results of simulations and experiments verify the validity of the theoretical analysis. Furthermore, the proposed soft-switching buck inverter has a strong practical significance in situations where medium and high power outputs are required.

Circuit Structure and Control Method to Reduce Size and Harmonic Distortion of Interleaved Dual Buck Inverter

A new circuit structure and control method for a high power interleaved dual-buck inverter are proposed. The proposed inverter consists of six switches, four diodes and two inductors, uses a dual-buck structure to eliminate zero-cross distortion, and operates in an interleaved mode to reduce the current stress of switch. To reduce the total harmonic distortion at low output power, the inverter is controlled using discontinuous-current-mode control combined with continuous-current-mode control. The experimental inverter had a power-conversion efficiency of 98.5% at output power = 1300 W and 98.3% at output power = 2 kW, when the inverter was operated at an input voltage of 400 VDC, output voltage of 220 VAC/60 Hz, and switching frequency of 20 kHz. The total harmonic distortion was &lt; 0.66%, which demonstrates that the inverter is suitable for high-power dc-ac power conversion.

A Modular Multilevel Dual Buck Inverter With Adjustable Discontinuous Modulation

Conventional single-cell dual buck inverters present high reliability, however they cannot be directly used in high voltage applications, because of the limited voltage rating of commercial switching devices. Therefore, a novel modular multilevel dual buck inverter (MMDBI), capable of processing voltage and power at higher levels, requiring a single dc input voltage, is proposed in this paper. Non-interleaved phase-shifted discontinuous modulation (NIPSDM) and interleaved phase-shifted discontinuous modulation (IPSDM) schemes are applied to the proposed inverter to reduce the current stress in the switching devices. Despite beneficial to the converter efficiency, the use of these discontinuous modulation approaches results in current zero-crossing distortion, which needs to be appropriately managed. In this work, theoretical values for the common-mode and differential-mode current ripples under NIPSDM and IPSDM modulation strategies are derived, and each switching operating mode is fully analyzed. From that, an adjustable current threshold value, which depends on the theoretical current ripple magnitude, is incorporated into the modulation strategy, producing a minimum switching overlap period between the two buck cells that eliminates the current zero-crossing distortion and produces a high-quality output current. Extensive simulation and experimental investigations are presented to demonstrate the feasibility and effectiveness of proposed topology and adjustable discontinuous modulation strategy.

PSO based Grid Tied PV System with Three Phase Dual Buck Inverter

PSO based Grid Tied PV System with Three Phase Dual Buck Inverter

New “Full-Bridge Buck Inverter–DC Motor” System: Steady-State and Dynamic Analysis and Experimental Validation

A mathematical model of a new “full-bridge Buck inverter–DC motor” system is developed and experimentally validated. First, using circuit theory and the mathematical model of a DC motor, the dynamic behavior of the system under study is deduced. Later, the steady-state, stability, controllability, and flatness properties of the deduced model are described. The flatness property, associated with the mathematical model, is then exploited so that all system variables and the input can be differentially parameterized in terms of the flat output, which is determined by the angular velocity. Then, when a desired trajectory is proposed for the flat output, the input signal is calculated offline and is introduced into the system. In consequence, the validation of the mathematical model for constant and time-varying duty cycles is possible. Such a validation of this mathematical model is tackled from two directions: (1) by circuit simulation through the SimPowerSystems toolbox of Matlab-Simulink and (2) via a prototype of the system built by using Matlab-Simulink and a DS1104 board. The good similarities between the circuit simulation and the experimental results allow satisfactorily validating the mathematical model.