Single-phase Inverter Research Articles

A Method for Separation of Power Semiconductor Packaging-Related Wear-Out Mechanisms Under Converter Operation

This paper proposes a new method to separate the package-related wear-out failure mechanisms of wire-bonded silicon-based power semiconductor switches: bond-wires lift-off and solder layer degradation. The proposed method takes the on-state voltages of power semiconductor device during the start-up transient and steady-state of power converters only, respectively, to realize the separation. It overcomes the challenges faced by existing separation methods that have complex off-line implementation process or are applicable to the devices with specific bond-wires connection and operational characteristic. The proposed method has the features of easy-of-implementation, on-line implementation, and relatively general application compared to existing methods. A case study with a single-phase inverter is demonstrated to prove the effectiveness of the proposed method.

Performance Analysis of Front-end Push-Pull Converter in a Single-Phase Inverter for Battery Current Ripple Reduction

Performance Analysis of Front-end Push-Pull Converter in a Single-Phase Inverter for Battery Current Ripple Reduction

Methods to Improve Suppression of Leakage Current Generation in Single-phase Non-isolated Photovoltaic Grid-connected Inverters

Analysis of methods to suppress leakage current through the topology of a single-phase inverter is carried out, aiming to address the phenomenon that disturbs the normal operation of electrical equipment and poses risks to human life when equipment integrates the electrical system into the grid. The topology of a single-phase inverter is taken as the research object, whose issues will be researched and summarized. First of all, by analyzing the single-phase inverter circuit, a simplified equivalent circuit is obtained. Then during the simplification process, it can be concluded that the generation of leakage current is related to the rate of change of common-mode voltage. After that based on this phenomenon, the general direction for suppressing leakage current has been obtained: when the electrical equipment links to the grid: keep Vcm constant, and four clear methods to suppress leakage current. Then reanalyze the way some new non-isolated grid-tied inverter topology how to suppress leakage current. Eventually, the conclusion would be reached.

Analysis of the performance of a 25-level inverter with a minimum number of switches and reduced harmonics for an environment solar energy

A multilevel inverter is a type of electrical equipment that converts a DC voltage to a higher AC value by creating a stepped waveform using several voltage levels. Multilevel inverters may create waveforms with three or more voltage levels, although regular inverters cannot. This separation results in lower harmonic distortion, decreased electromagnetic interference, and higher efficiency. An innovative MLI design that makes use of fewer switches and PV sources solves this problem. The Perturbation and Observation (P&O) approach is used to derive the Maximum Power Point Tracking (MPPT) from these PVs. The MC-SPWM technique was used in the design, simulation, and construction of single-phase and three-phase multilevel inverters with inverter levels ranging from three to twenty-five. The technique's cornerstones are phase disposition (PD-PWM) and power quality improvement. The main goal of the paper objectively analyzing the issue of power-system harmonics, providing information on causes, effects, and useful harmonic mitigation strategy.

Design and development of single-phase inverter for locomotives based on SVPWM

For locomotive in high-power inverter power supply output efficiency is low, the level is not stable, push-pull circuit before the switch tube of high pressure, low utilization rate of the original winding transformer problem, designed and developed a kind of single phase inverter power supply based on SVPWM control. The inverter is designed with a modular structure with a rated power of 4KW, which is used to supply power to the cab electrical apparatus and auxiliary air compressor at both ends of the locomotive. It is composed of a filter circuit, a front-end boost control drive circuit, a full-bridge DC boost circuit, an inverter control circuit, a voltage and current sampling circuit, a back-end full-bridge inverter circuit and a protection circuit. The front stage of the inverter adopts a full bridge chopper circuit topology, while the rear stage achieves SVPWM control through the Vacon NXS control box. Finally, a power supply prototype was produced through simulation verification, and the results showed that the designed power supply met the design requirements.

A simple zero-voltage switching technique for a single-phase inverter based on bi-directional inductor current

The majority of soft-switching inverters often use auxiliary semiconductor switches that run for extremely brief periods to provide ZVS conditions for the main switches, potentially raising the inverter system’s cost. This work presented a simple zero-voltage switching (ZVS) approach by employing a bi-directional inductor current for the single-phase inverter, which reduced the cost of auxiliary switches and simplified the soft-switching inverter design. All switches can achieve ZVS operation without additional resonant components. The conventional PWM control strategies are applied in the proposed technique, and thus the problems existing in variable switching frequency converters are removed. This article describes the soft-switching approach and detailed circuit functioning. Different key parameters are optimized to improve efficiency. To confirm the suggested ZVS method, a hardware inverter prototype is created, built, and tested. To validate the inverter’s characteristics and validity, experimental results are presented.

Design and Simulation of a Cascade Boost DC-DC Converter as a Single-Phase Inverter Power Supply

Currently, the need for new renewable energy is getting higher, so the development of equipment in supporting this is increasingly rapid. designing an inverter that has a high output voltage can be done in several ways, namely by developing from the basic topology of the inverter or developing an inverter input side voltage boost DC-DC converter that has a high gain ratio capability or by using a step up transformer as an AC voltage booster, but it is inefficient considering that the step up transformer has a heavy weight, and reduces space. In this research the researchers designed a cascade boost converter as a single-phase inverter power supply. The cascade boost converter is used as a DC voltage increase where the DC high voltage is entered into a single phase inverter as a DC power supply and the inverter converts from DC-AC. Without using a step up transformer as an AC voltage booster. The inverter is combined with an LC filter as a wave filter to make it close to a sinusoidal wave. The simulation results show that the whole system is able to output a voltage of 220VAC RMS with a frequency of 50Hz.

Analysis of Active Islanding Methods for Single phase Inverters

This paper presents the analysis and comparison of the main active techniques for islanding detection used in grid-connected single phase inverters. These techniques can be divided into two classes: techniques introducing positive feedback in the control of the inverter and techniques based on harmonic injection by the inverter. The algorithms mentioned in this work are simulated in PSIMTM in order to make a comparative analysis and to establish their advantages and disadvantages according to IEEE standards.

A partial soft-switching SiC-based ANPC single-phase inverter with loss model-based dead time optimization for grid-tied PV systems

Single-phase string inverter has been widely applied to grid-tied photovoltaic (PV) rooftop applications for its renewable energy. However, the inherent attribute of intermittency in solar energy may induce instability and unqualified power. To meet the grid-interconnection standards, high demands of efficiency and harmonic distortion need to be imposed on DC/AC inverters. Conventional soft-switching inverters used to sacrificing auxiliary resonant circuits to exchange for soft switching. This requires additional costs as well as sufficient dead time to discharge junction capacitances of all switches, which exacerbates total harmonics distortion (THD) induced by dead-time effect. To improve, this paper proposes a partial soft-switching silicon carbide (SiC) -based active neutral-point-clamped (ANPC) inverter, which possesses high efficiency, eligible dead time, and no auxiliaries. 650-V SiC MOSFET is adopted for its smaller output capacitance compared with Si device. Hybrid PWM modulation is utilized to achieve partial soft switching. Whereas, the soft switching realization range and power losses highly depend on the dead time. To achieve less power loss and improved dead time effect, this paper proposes a loss model-based dead time algorithm through a Power Loss VS. Dead Time mathematical loss model. Moreover, the mechanism of the dead time affected by soft switching is explored. The transition modes, dead time configurable boundaries, and design procedure are also analyzed in detail. A 1-kW prototype is demonstrated with the input of 800 V and the rated output of 220 V/ 4.5 A. Its efficiency could reach 99.6% with THD=0.95% at full power level.

Fuel cell stack design and modelling with a double-stage boost converter coupled to a single-phase inverter

Abstract A comprehensive proton-exchange membrane fuel cell stack model was developed and integrated with a two-stage DC/DC boost converter. It was directly coupled to a single-phase (two levels—four pulses) inverter without a transformer. The pulse-width modulation signal was used to independently regulate every converter phase. The converter was modelled using a MATLAB®/Simulink® environment and an appropriate voltage control method. The analysis features of the suggested circuit were created and, through established experiments, the simulation results were verified. A single-phase (two levels—four pulses) inverter control circuit was tested and it produced a pure sinusoidal waveform with voltage control. It matches the voltage of the network in terms of amplitude and frequency. A sinusoidal pulse-width modulation approach was performed using a single-phase (two levels—four pulses) pulse-width modulation inverter. The results demonstrated an enhancement in the standard of the output wave and tuned the dead time with a reduction of 63 µs compared with 180 µs in conventional techniques.

Experimental and Simulated Investigation of a Single-Phase Transformerless H5 Inverter Topology

This paper aims to simulate and experimentally apply a single-phase transformerless H5 inverter topology. The H5 inverter topology is simulated in MATLAB/Simulink environment as both off-grid and grid-connected. The simulation results of the grid-connected system are evaluated in terms of output voltage/current, total harmonic distortion (THD), and injected active and reactive powers into the grid. The off-grid system is evaluated regarding load current, inverter output voltage, efficiency, and THD. Despite the variable output load, the results offer good THD values that comply with the IEEE 1547 standard. Additionally, experimental studies are conducted on the single-phase off-grid transformerless H5 inverter. A digital processing unit is utilized to control and display the output voltage of the H5 inverter system in real-time mode. PI and Fuzzy PI controllers are used for output voltage control. The obtained results reveals that the investigated topology outperforms its counterparts.

New boost type single phase inverters for photovoltaic applications with reduced device count.

In recent years, single-stage boost inverters with common ground have shaped the inverter markets due to the many benefits associated with these types of inverters, including their high efficiency, single control scheme, and integrated boost converter. A new boost-type inverter that utilizes a common ground and has fewer switches is proposed in this article. It uses two DC-link capacitors connected in parallel and discharged independently while being charged simultaneously. The voltage for the positive and negative half cycles is supplied by the capacitors located at the top and bottom of the circuit, respectively. In addition, a comparison is made between the proposed circuit and the boost inverter already in use in the literature. Using PLECS as the computing software, the efficiencies are determined depending on the various percentages of output power. To validate performance, present experimental data, and attain the best possible efficiency of 97%, a 400 W prototype model is constructed. In addition to that, the breakdown of the costs is shown.

An efficient power decoupling topology circuit based on a novel three-port three-switches flyback series circuit.

Both filter inductors, electrolytic capacitors, and radiators play a significant role in the inverter of a PV (Photovoltaic) power generation system. These three parts are the largest in an inverter, which affects the performance of the inverter. Aimed to improve the power density of a single-phase PV grid-connected inverter with a decoupling function. This paper derived the control principle that can reduce the volume of the inductor, decoupling capacitor, and the loss of the switching device to begin with the mathematical function of power processing of the filter inductor. And then, the authors deduced a boost-type power decoupled single-phase inverter topology. Based on a novel three-port three-switches flyback series circuit, this paper proposed an efficient power decoupling topology circuit for extracting the maximum power density of a single-phase grid-connected PV inverter. Finally, this article operated the simulation and experiment. Both the simulated and experimental results verified that the proposed method works well.

A Novel Interphase-Bridging Single-Phase Inverter for Photovoltaic and Energy Storage Connected to Railway Traction Power Supply System

A Novel Interphase-Bridging Single-Phase Inverter for Photovoltaic and Energy Storage Connected to Railway Traction Power Supply System

Enhancing Fault Detection and Diagnosis in Grid-Connected PV Systems under Irradiance Variations: A Novel Approach Using New Data Normalization Techniques on RBFNN Algorithm

With the global shift towards renewable energy, the reliability and efficiency of photovoltaic (PV) systems have become paramount. A crucial aspect of this is the timely detection and accurate classification of faults within the system. In fact, accurate fault detection and classification in the diagnostic systems can prevent severe damages, enhance operational efficiency, and prolong the lifespan of the installations. This paper introduces a novel data normalization technique tailored for enhancing the performance of meta-heuristic algorithms (namely RBFNN) applied to single-phase inverter current signals for fault detection in PV systems. While conventional normalization technics have shown their limitations in capturing the nuances of PV system faults, our proposed strategy demonstrates a more effective approach in preserving fault-specific features in the data. The proposed method is evaluated using multiple datasets encompassing a variety of fault scenarios. Empirical results show a significant improvement in both fault detection rates and classification accuracy. This study not only presents a breakthrough in PV system fault diagnosis but also sheds light on the broader potential of specialized normalization techniques in all signal-processing field, such as biomedical signal processing, industrial process control, or financial time series analysis, and other domains. The supremacy of the proposed diagnostic in reducing false alarms and providing more clear-cut classifications is highlighted by several simulations under Matlab-Simulink.

Single PCB sensor-based output current reproduction for three-phase inverter systems

This study proposes a practical output current measurement system in a three-phase inverter with a single printed circuit board (PCB) Rogowski coil sensor inserted in the bus between the DC-link capacitor and the power semiconductor module. This system demonstrates its advantage over conventional output current sensors, such as the Hall effect current sensors, in terms of the size, weight, operation temperature and cost. The system can be applied to 6-in-1 power modules as it does not require sensors in the inverter phase legs.In our previous works, we have developed a method called “envelope tracking”, which is used in this system as well. This method traces the switching current instead of the output current to reproduce the output current signal in real-time. Envelope tracking successfully reproduced the output current waveform for single phase inverters under certain conditions. However, a large error is observed in the three-phase inverter demonstration under a high switching frequency (narrow pulse) or when the switching of different phases overlap each other. These errors must be completely suppressed to implement the system for feedback control in three-phase inverters.In this study, a new analog basis output current waveform reproduction system is introduced to suppress the above mentioned errors. This system is implemented in a three-phase insulated-gate bipolar transistor (IGBT) inverter and successfully reproduces the output current with a single PCB sensor inserted between a 6-in-1 IGBT power module and DC-link capacitor, operating under a switching frequency of 3.5–7.0 kHz and output current of 6 A with DC-link voltage of 150 V.

Improvement of grid injected currents in single-phase inverters rejecting DC link voltage oscillations based on multi-resonant filtering

The operation of grid-tied single-phase inverters generates oscillations in its DC link voltage. If only active/reactive power is controlled by the inverter, this oscillation is at twice the grid frequency. In situations where the inverter output current and/or the grid voltage also has harmonic components, the DC link voltage becomes also polluted by oscillating components at even multiple frequencies of the grid voltage. Such oscillations are propagated through the DC link voltage control loop, increasing the THD index of grid current reference signal. To solve this drawback, this article proposes the insertion of a multi-resonant filter into the DC link voltage control loop, ensuring a harmonic free grid current reference signal. With the proposed filter and without any increase in the power circuit, the use of smaller capacitances in the DC link is allowed, since the DC link voltage oscillation does not interfere in the power quality indexes of the controlled current. A filter tuning methodology is presented to ensure that the design of each filter and of the DC link voltage controller is independent, relating the filter settling time and the system stability. At the same time, the use of the proposed filter allows the voltage controller to be tuned at higher frequencies, improving the DC link voltage dynamic response. The proposal is experimentally validated through a single-phase grid-tied double-stage photovoltaic (PV) system, that can also operate only as a parallel active power filter (PAPF) or, simultaneously as a multifunctional PAPF + PV system.

Improved Dynamic Response of a Single-Phase-Integrated KY Boost Converter with an MLI System of a DC-AC Converter in Motor Speed Regulation

KY boost converter (KBC) finds wide application in photovoltaic (PV) and single-phase inverters. In this study, a novel KBC containing seven levels of a multilevel inverter (MLI) is presented. Here, KBC between the direct current (DC) source and the inverter is proposed. Moreover, the authors considered a closed-loop response of the KBC-MLI system with a proportional integral (PI) controller and a fractional-order PID (FOPID) Controller. The main purpose of this suggested technique is to match the output current, total harmonic distortion (THD), and dynamic response of closed-loop PI and FOPID-controlled KBC-MLI systems. The proposed model is simulated with the MATLAB software, and the attained outcome illustrated an enhanced dynamic performance by using the FOPID-controlled KBC-MLI system. The simulation results of the KBC-MLI technique have been evaluated against the theoretical models. Finally, extensive experiments were carried out to validate the theoretical results.

Finite Control Set Model Predictive Control (FCS-MPC) for Enhancing the Performance of a Single-Phase Inverter in a Renewable Energy System (RES)

A single-phase five-level T-type topology has been investigated in this article. This topology has emerged as a viable option for renewable energy systems (RES) due to its inherent benefits. The finite control set model predictive control (FCS-MPC) strategy has been implemented to this topology in order to improve the performance and overall reliability of the system. This control strategy empowers the inverter to predict future behavior based on a discrete set of control signals, enabling precise modulation and high-speed response to system dynamics. In the realm of RES, integration of FCS-MPC with multilevel inverters (MLIs) holds great potential to enhance energy conversion efficiency, grid integration, and overall system reliability. The article is structured to present an overview of the evolving landscape of power electronic systems, and the advantages of FCS-MPC. This paper provides a comprehensive analysis of the FCS-MPC control strategy applied to the single-phase five-level T-type topology. The study covers various aspects including the theoretical framework, hardware development, and experimental evaluation. It is obvious from the analysis that this inverter topology is reliable. Several redundant states make it fault-tolerant which helps in maintaining the output voltage at the same level even in the fault conditions. Additionally, the results show that the output load voltage is maintained at the same level irrespective of load change. Also, output load voltage has maintained the high-quality sinusoidal characteristics as the total harmonic distortion (THD) is very low. With all these features, this system is suitable within the framework of RES.

The Concentrator for Single-Phase Inverters with Three-Phase Output Using Magnetically Coupled Reactors

This paper presents a passive concentrator for single-phase inverters with a three-phase output, which uses magnetically coupled reactors. Due to the development of renewable energy systems, the proposed systems may enable the easier integration of converters in the form of inverters with the power system. Two variants of cooperation of the concentrator with single-phase voltage inverters were considered. The first variant proposed a system topology in which three single-phase full-bridge inverters were connected to the concentrator, while the other variant proposed six half-bridge inverters. A control system of the inverters that does not use PWM was developed. A common star point was created for the supply voltages in the form of a capacitive divider covering all the inverters. An analysis of the concentrator system was presented, taking into account the cooperation with inverters. The overall power of the TDSλ system was defined and the relationship for its determination was given. Simulation studies were described, presenting the obtained voltage and current waveforms. The impact of changing the supply voltage of the inverters on the operation of the concentrator and the shape of the output voltages was assessed. The proposed systems allow you to connect 3 or 6 single-phase inverters. The use of magnetically coupled reactors enables the use of a magnetic system of lower power and size. The described concentrators enable the generation of multi-level three-phase output voltage with a low THD content.