Single-phase Inverter Research Articles

Simplified Finite Control Set Model Predictive Control for single-phase grid-tied inverters with twisted parameters

Large computational burden, time delay, and the necessity for precise modeling accuracy are the three main challenges for Finite Control Set-Model Predictive Control (FCS-MPC) in single-phase grid-tied inverters. To solve these issues, a twisted parameter scheme is proposed for the single-phase inverter in this article. Firstly, the law regarding the influence of the model parameter on the current total harmonic distortion (THD) is outlined, emphasizing that a decrease in the inductance parameter leads to a corresponding reduction in current THD. Second, a linear observer is constructed to identify the actual value of inductance and resistance, and an RBF-GA (Radial Basis Function neural network-Genetic Algorithm) scheme is used to obtain the optimal twisted parameter. Subsequently, the efficacy of the proposed methods was verified utilizing MATLAB/Simulink simulations, with further validation conducted through hardware-in-the-loop (HIL) experiments performed on Speedgoat performance real-time target machines. Simulation and experimental results demonstrate that within a specific range, decreasing the inductance parameter can significantly improve the quality of the current. Furthermore, the proposed method outperforms the traditional delay compensation method by reducing computational complexity, minimizing prediction error, and decreasing the number of switching transitions.

A Novel Single-Stage Boost Single-Phase Inverter and Its Composite Control Strategy to Suppress Low-Frequency Input Ripples

Low-frequency pulsating ripples exist on the input side of a single-phase inverter, which bring some adverse effects and harm to the inverter and photovoltaic power generation system. In order to suppress the low-frequency pulsating ripple and reduce the filter circuit parameters, a novel single-stage boost single-phase inverter is proposed, which can suppress low-frequency ripple. And a three-closed-loop compound control strategy that can suppress input low-frequency ripples under the limitation of an energy storage inductor current and buffer capacitor voltage is proposed. The circuit topology, control strategy, key circuit parameters design, system modeling, and simulation of the inverters are deeply analyzed and studied. Simulation and experimental results show that the inverter has a good ability to suppress input low-frequency ripples.

Single source self balanced switched capacitor based singe phase nine level inverter

Multilevel inverters are becoming increasingly significant due to their ability to efficiently convert power in various applications such as renewable energy systems, electric vehicles (EVs), and industrial drives. The growing need for efficient power conversion in these areas has driven heightened interest in multilevel inverters. High inrush current is required for numerous applications, including variable frequency drives, single-phase or three-phase machine drives, locomotives, electric vehicles. However, managing this inrush current is crucial to prevent damage to the power source and other connected equipment, as well as to ensure smooth and reliable operation. The solution for this is to provide isolation between load and source. The proposed single phase switched capacitor multilevel inverter possess the feature of virtual isolation between the load and the source. This topology consists of a switched capacitor cell network and a multilevel inverter. In this work, a simplest architecture is used for the MLI section to reduce the number of switches. The MLI section consists of only eight switches. Although the switched capacitor network in this topology consists of a higher number of switches, the switches in the network carry only very low current, resulting in negligible losses. Additionally, the switched capacitor network is highly modular in nature. The proposed single-phase inverter can be converted to a three-phase multilevel inverter (MLI) by connecting identical units in each phase, with the reference sinewave signal for the pulse-width modulation technique derived from the corresponding phases. Consequently, this proposed topology is suitable for both low-power and high-power applications. This work demonstrates that self-voltage balancing of the level capacitors can be achieved without the need for auxiliary components.In this design, the level capacitors act as the source to the load and are charged through switched capacitors. The voltage THD in the suggested work is less than 5%, which is in accordance with IEEE 519 standards. High voltage gain, better load, and line regulation, are other significant advantages of this novel topology. Another feature of this work is simplicity in design and can be easily extended to higher voltage levels. Comprehensive simulation and experimental results are provided to validate the precise performance of the proposed multilevel inverter

Performance analysis of a new single-phase transformerless PV inverter structure based on a buck-boost converter

A single-phase inverter based on a buck-boost converter is increasingly used in modern power electronics, particularly in solar photovoltaic systems. Unlike traditional inverters that utilize transformers to electrically isolate the solar system from the power grid, this transformerless design enhances efficiency, reduces weight, and lowers costs. However, the absence of a transformer introduces challenges related to Electromagnetic Compatibility (EMC) and the potential for increased leakage currents, which must be carefully managed to ensure system safety and performance. In this paper, the performances of a new configuration of a single-phase transformerless PV inverter based on a dc-dc buck-boost converter is proposed and analyzed. Since it is the only switch (mosfet) in the DC-DC converter that operates at high frequency, and it is controlled by pulse width modulation (PWM) to adjust the output voltage. This allows for flexible voltage conversion, enabling the inverter to either step up (boost) or step down (buck) the input voltage as needed. Therefore, switching losses can be significantly reduced to improve efficiency and reduce electromagnetic interference of the single-phase inverter structure. In order to demonstrate the EMC performances and evaluate the leakage current of the proposed structure, an EMC model is developed under the Simscape-MATLAB/Simulink environment, this model offers an EMC analysis including the prediction of leakage current over a frequency range from 100 Hz to 2 MHz. The results clearly showed that the level of the Total harmonic distortion (THD), as well as the levels of leakage current, are below the requested EMC standards.

Design of a optimal robust adaptive neural network-based fractional-order PID controller for H-bridge single-phase inverter

Adaptive Neural Network- based Fractional-order PID Control (NN-FO-PID) approach is designed for H-bridge inverter. This inverter has an LC filter to decrease the level of Total Harmonic Distortion (THD) that can affect the efficiency of the system. In addition, the reduction of THD and stability insurance of the filter are challenging performances. To fulfill this function, a fractional order proportional integrated derivative (FO-PID) controller is developed for the inverter. A few merits of the Fractional-Order notion as a useful technique include reduced sensitivity to noise and parametric fluctuation; however, for a wider range of disturbances, such as noise, this approach shows an unsuitable practical application based on its fixed gain values. Moreover, having parameters uncertainties including parametric variations, load uncertainty, supply voltage variation uplifts this challenging condition severely, and the parameters need to be adjusted once more for more dependable operations. As a result, the control parameters must be optimized once more to provide ideal operations. Here, an adaptive mechanism is proposed based on neural network structure to optimize the gains of the FO-PID controller for better performances. In real applications, this approach has some benefits, since it uses the Black-box technique, which does not necessitate a precise mathematical model of the system, resulting in a reduced computational burden, simple implementation, and reduced dependence on the model’s states. Even under extremely difficult circumstances, the artificial neural network structure effectively optimizes the FO-PID gains in real-time. This benefit can reduce the amount of THD-level for the inverter, properly. Additionally, to have a proper response in the first step condition, and trying to reduce the level of dangerous conditions, based on benefits of the ant lion optimization method, it is considered to select the initial values of the FO-PID controller gains. Here to verify the superiority of the proposed controller, PID and FO-PID controllers are offered to drive a comparison with this method, which are optimized using the PSO optimization algorithm. The analysis of simulation data shows that the suggested control strategy is appropriate for maintaining stability as well as adequately compensating for disturbances and uncertainties in the inverter. Furthermore, with the help of this controller, THD level decreased lower than 2 percent.

Diagnostics on Power Electronics Converters by Means of Autoregressive Modelling

Power conversion systems for wireless power transfer (WPT) applications have demanding requirements for continuity of service, besides being operated with stressing environmental conditions. Diagnostic and prognostic programs are thus quite useful and this work shows a novel approach based on the analysis of spectra of an autoregressive (AR) model to recognize a wide range of faulty devices, including incipient faults, when deviations from nominal parameters begin to manifest. AR modeling provides cleaner and easier to interpret spectra, where only the salient features remain, and they are more sensitive to variations in the corresponding time domain waveforms. A log spectral distance is calculated that successfully separates healthy and faulty states of the feeding single-phase inverter, even in challenging scenarios of poor signal-to-noise ratio.

Topology and Control for Second Harmonic Current Reduction in Two-Stage Single-Phase Inverter Without Electrolytic Capacitors

Topology and Control for Second Harmonic Current Reduction in Two-Stage Single-Phase Inverter Without Electrolytic Capacitors

Single-phase online interactive uninterruptible power supply design

The single-phase on-line interactive uninterruptible power supply (UPS) designed in this paper consists of three circuits, namely, a single-phase power factor correction circuit, a single-phase inverter circuit, and a bi-directional DC/DC circuit, each of which contains a main circuit as well as a control circuit. The principle, parameter design and control circuit design of each circuit are briefly described. The simulation model of the UPS is constructed, and the simulation results in normal and abnormal utility power are given to verify the correctness of the design.

A Novel Chaos Control Strategy for a Single-Phase Photovoltaic Energy Storage Inverter

The single-phase photovoltaic energy storage inverter represents a pivotal component within photovoltaic energy storage systems. Its operational dynamics are often intricate due to its inherent characteristics and the prevalent usage of nonlinear switching elements, leading to nonlinear characteristic bifurcation such as bifurcation and chaos. In this paper, a deep investigation of a single-phase H-bridge photovoltaic energy storage inverter under proportional–integral (PI) control is made, and a sinusoidal delayed feedback control (SDFC) strategy to mitigate the nonlinear characteristics is proposed. A frequency domain mapping model of the system is established, then, by analyzing the Jacobian matrix and equilibrium points, the bifurcation diagram is formed, and finally, the stable operational domains are determined under double and triple bifurcation parameters. Through simulation experiments, the efficacy of this strategy is validated. The findings show that through the control strategy, the stable operational envelope of the inverter can be greatly expanded and the nonlinear dynamic phenomena can be notably suppressed.

Algorithm for Assessment of the Switching Angles in the Unipolar SPWM Technique for Single-Phase Inverters

Algorithm for Assessment of the Switching Angles in the Unipolar SPWM Technique for Single-Phase Inverters

Limits of Harmonic Stability Analysis for Commercially Available Single-Phase Inverters for Photovoltaic Applications

Limits of Harmonic Stability Analysis for Commercially Available Single-Phase Inverters for Photovoltaic Applications

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.

High-Performance Multi-Level Inverter with Symmetry and Simplification.

This paper presents a high-performance, multilevel inverter with symmetry and simplification. This inverter is a single-phase, seven-level symmetric switched-capacitor inverter based on the concept of the double voltage clamping circuit connected to the half-bridge circuit. Above all, only a single DC power supply is used to achieve a single-phase inverter with seven levels and a voltage gain of three. In addition to analyzing the operating principle of the proposed switched-capacitor multilevel inverter in detail, the stability analysis and controller design are carried out by the state-space averaging method. The feasibility and effectiveness of the proposed structure are validated by some simulated results based on the PSIM simulation tool and by some experiments using FPGA as a control kernel, respectively. However, in this study, the switches were implemented by MOSFETs to meet a high switching frequency. These MOSFETs can be replaced by IGBTs in the motor drive applications so that the used switching frequency can be reduced.

Comparative Analysis of Bipolar and Unipolar SPWM Techniques in PIC-Based Pure Sine Wave Single-Phase Inverters

This paper provides a comparative analysis of bipolar versus unipolar Sinusoidal Pulse Width Modulation (SPWM) in DC-AC inverters, focusing on Total Harmonic Distortion (THD) across modulation indices and the latter’s effects on the R-L loads. Using the PIC18F2431 microcontroller for its efficiency, a single-phase inverter accomplished to deliver a high-fidelity sine wave. This study discovered that while both SPWM methods reduce harmonics, the unipolar approach yields more uniform THD reduction and superior performance, particularly noticeable in RL load conditions, where minimal harmonic distortion is crucial. The bipolar inverter, despite a higher initial THD, shows a considerable improvement at higher indices, significantly enhanced by an LC low-pass filter. This filter is a key component in achieving sub-1% THD levels at full modulation, ensuring optimal sine wave quality. The findings highlight the operational differences between the SPWM techniques and the importance of the LC filters in ameliorating the inverter output for various power applications.

Review on Close Loop Control of Novel Transformer Less Inverter Topology for Single Phase Grid Converter

The continuous urge for improvement in our standard of living has increased the consumption of electrical energy by leaps and bounds. This hike in energy consumption, draining of fossil fuels and degrading global environment has led to invention of green power generation systems. Thus, the global demand for renewable resources has led to flourishing of photovoltaic (PV) market. The enabling technology in the PV systems is the inverter, which could be either: 1) with transformer isolated or 2) without transformer non-isolated (transformer-less inverter). Recently, single phase transformerless voltage source inverters (VSI) have been extensively used for distributed photovoltaic grid tied systems. The objective of this paper is to review a few notable topologies and propose a new topology for transformer-less photovoltaic inverter. The analysis and design of the proposed topology is verified by simulating it on PSIM. Furthermore, the simulation results are validated by testing a proof-of-concept laboratory hardware prototype rated at 250 W. Keywords— Photovoltaic (PV) systems, transformer-less, single phase inverter

HIL Investigation of a Single-Phase Inverter for a Tokamak Non-Axisymmetric In-Vessel Coil Power Supply

HIL Investigation of a Single-Phase Inverter for a Tokamak Non-Axisymmetric In-Vessel Coil Power Supply

Multilevel Aircraft-Inverter Design Based on Wavelet PWM for More Electric Aircraft

This paper proposes a comprehensive power system designed for the use of a more electric aircraft power distribution system. Instead of traditional Nicad battery solutions as the energy source of the aircraft power system, lithium battery structures, which are a recent and promising solution in the field of aviation power systems, are modeled and analyzed. In this study, a WPWM-based, single-phase, multi-level pure sine wave static aircraft-inverter system is designed and integrated to improve the performance of conventional aircraft power systems. In the designed power system, a boost converter structure is proposed that boosts 28 VDC-to-270 VDC voltage coming from the lithium–ion battery pack and can reach a steady state in 0.032 s. The performance of the modeled WPWM-based aircraft-inverter system, compared to SPWM Bipolar and Unipolar switching techniques commonly used in single-phase inverter designs, reveals a THD reduction of approximately 27% with WPWM, resulting in a THD value below 2% for both load current and load voltage. As a result of the study, a power system that will enable the aircraft avionics, ventilation, and navigation systems to perform better than conventional power systems and comply with aircraft electric-power characteristic standards has been designed and detailed.

Wind–PV–Battery Hybrid Off-Grid System: Control Design and Real-Time Testing

The paper presents the design and implementation of decentralized control for a PV–wind–battery hybrid off-grid system with limited power electronics devices and sensors. To perform well without using any maximum power point tracking (MPPT) technique from the wind turbine (WT) based on a permanent-magnet brushless DC generator (PMBLDCG) and solar panels (PVs) and balance the power in the system, a cascade control structure strategy based on a linear active disturbance rejection controller (LADRC) is developed for the two-switch DC-DC buck-boost converter. Moreover, to ensure an uninterruptible power supply to the connected loads with a constant voltage and frequency, a cascade d-q control structure based on LADRC is developed for the interfacing single-phase inverter. Furthermore, the modeling and controller parameters design are presented. The performance under all operation conditions of the hybrid off-grid configuration and its decentralized control is validated by simulation using MATLAB/Simulink and in real-time using a small-scale hardware prototype.

Comparative Analysis of Single-Phase MOSFET-Based and IGBT-Based Inverters: A Performance Evaluation

his research paper explores the application of MOSFETs and IGBTs in the development of single-phase inverters. An Inverter is an electronic device or circuit that converts DC power into alternating current AC power. Commencing with an overview of inverters and their versatile applications, the study thoroughly examines the distinct characteristics of MOSFETs and IGBTs. It then provides detailed insights into the hands-on creation of single-phase inverters using these semiconductor components. Employing simulation tools, the study rigorously compares their efficiency, waveform quality, and responsiveness to dynamic changes. These findings contribute valuable information for selecting the most suitable semiconductor technology when designing practical and reliable single-phase inverters across a spectrum of applications.

ENQUÊTE DE PERFORMANCE D'UN ONDULEUR PV MONOPHASÉ SANS TRANSFORMATEUR CONNECTÉ À UN RÉSEAU BASSE TENSION

Due to their high efficiency and reduced size and weight compared to transformer-based inverters, transformerless single-phase inverters are the most widely used in photovoltaic systems connected to the low-voltage grid. Unfortunately, the absence of galvanic isolation leads to ground faults caused by capacitive leakage current flow and deterioration of the inverter's insulation resistance on the dc side. This paper examines the performance of the three transformerless single-phase inverters of the first grid-connected photovoltaic system in Algeria under adverse weather conditions, such as rain, as there is no galvanic isolation between the dc and ac side of the inverter, making operation of the photovoltaic system more difficult. The flow of capacitive leakage current from the earth to the inverter output is one of the two phenomena, resulting in protection devices being triggered involuntarily. The second phenomenon is system shutdown due to a decrease in the inverter's insulation resistance at the input. The VDE 126-1-1 standard integrated into the inverter, which defines the safety requirements for grid-connected photovoltaic systems, is used in this article to manage and analyze both phenomena.