Bridge Inverter Research Articles

Research on Open Circuit Fault Location and Fault Tolerant Control of Inverter Power Transistor

As the key equipment of power conversion, the stability of the inverter directly affects the working state of the equipment. Aiming at the open circuit fault of the power tube, this paper designs a fault diagnosis and fault tolerance scheme of a three-phase bridge inverter based on the current signal. Firstly, the amplitude and phase characteristics of the current vector are used to judge the fault and fault location of the power tube. Then the output fault characteristic signal is converted into a fault-tolerant control signal. The fault leg is switched into a fault-tolerant leg under fault-tolerant control of the inverter bridge. The simulation results show that the diagnosis method proposed in this paper can judge the health and fault status of the inverter with high accuracy and achieve fault tolerant control, improving the stability of the inverter.

Design and analysis of three phase inverter based Solar PV powered single switch Buck-Boost converter with reduced THD for industrial applications

The development of economical and sustainable eco-friendly renewable source powered power electronic converters have become more attractive in various areas such as automotive, household and industrial applications etc., Bucking and boosting of voltage according to the requirement is also much needed. So, this work proposes a solar PV powered single switch buck-boost converter which reduces implementation cost, minimal voltage and current stress across the capacitors and diodes and less switching power losses. The work structure comprises of solar PV source with modified P and O algorithm based MPPT, single switch buck-boost dc-dc converter, battery backup to store excess energy, three phase inverter with sinusoidal PWM to find optimal switching angles for harmonic control and 3Φ induction motor load. Here reduction of THD is applied to the line to line voltage of the inverter. Performance analysis of the proposed circuit is done using MATLAB/SIMULINK platform. A detailed steady state analysis of the dc-dc converter topology is also analyzed to system stability. The proposed single switch buck-boost converter is designed to provide an output voltage and current of 363V, 45.5A DC from 520V, 35A PV array. The designed converter is then employed to run a three phase full bridge inverter with 440V, 15A AC. From the simulation results, it is found that the solar powered single switch buck-boost with MPPT is stable, efficient with minimal losses and less THD with better quality output.

Photovoltaic Inverter Reliability Study through SiC Switches Redundant Structures

Reliability is a very important issue in power electronics; however, sometimes it is not considered, studied, or analyzed. At present, renewables have become more popular, and more complex setups are required to drive this type of system. In the specific case of inverters in photovoltaic systems, the user’s safety, quality, reliability, and the system’s useful life must be guaranteed. In this paper, the reliability of a full bridge inverter is predicted by calculating metrics such as failure rates and Mean Time Between Failures. Reliability is obtained using different types of structures for SiC MOSFETs: serial systems, active parallel redundant systems, and passive parallel redundant systems. Finally, the reliability study shows that a system with a passive parallel redundant structure is more reliable and has a higher useful life compared to the other structures.

Simulation Approach for Torque Ripple Minimization of BLDC Motor

This project presents the design and implementation of neural network controller for reducing torque ripples in permanent magnet brushless DC (PMBLDCM) motor drive with trapezoidal back-emf. The performances of the proposed neural network controller are compared with the corresponding fuzzy PI controller and conventional PI controller. Simulation results are used to show the abilities and shortcomings of the proposed speed regulation scheme for brushless dc motor which is considered as a highly nonlinear dynamic complex system. Matlab/Simulink software was used to simulate the proposed model. Buck-boost converter connected in between the input DC source and three phase bridge inverter, used for minimizing the commutation torque ripples in Permanent Magnet Brushless DC Motor is presented in this paper. Torque during the commutation period depends on phase current which is not undergoing commutation, so by controlling it, torque ripple can be minimized. Moreover, a greater DC link voltage is needed during the commutation time period in comparison to the normal conduction period. The Buck-boost converter operates in boost mode in commutation period for stepping up the DC voltage to the inverter. A simple mode switching circuit is employed to amend the output modes of the Buck-boost converter in normal and commutation time intervals. Simulation studies of this topology are carried out in MATLAB/Simulink environment. Index Terms – Permanent Magnet Brushless DC Motor (PMBLDCM), Buck-boost Converter, Commutation Time period,PI Controller.

Review and comparison of methods for limiting leakage currents in single-phase transformerless PV inverter topologies

Transformerless inverters are widely used in different photovoltaic nonisolated ac module applications, mainly in grid-tied photovoltaic (PV) generation systems, due to the benefits of achieving high efficiency over a wide load range, and low cost. Various transformerless inverter topologies have been proposed to meet the safety requirement of low ground leakage currents, such as specified in the VDE-4105 standard and low-output ac-current distortion. Topology modifications of transformerless full bridge inverters are designed to balance and maintain a constant common mode output voltage, thereby eliminating or reducing leakage currents. This article reviews and compares the different methods for limiting leakage currents in known topologies of the full-bridge transformerless inverters, such as: H4, H5, H6, HERIC, and their improvements. The main topologies and strategies used to reduce the leakage current in transformerless schemes are summarized, highlighting advantages and disadvantages and establishing points of comparison with similar topologies. To compare the properties of different medium to high power inverters, PV inverter topologies were implemented using IGBTs and tested with the same components, same simulation parameters in PSPICE to evaluate their performance in terms of energy efficiency and leakage current characteristics. The detailed power stage operating principles, extended PWM modulator, and integrated universal gate driver with galvanic isolation in the transmission path of control signal for all IGBTs of the inverter, as well isolated and floating bias power supply for gate drivers are described.

Analysis of Exchange Power in the Power System of an Unmanned Aerial Vehicle with a BlDC Engine

The purpose of this work is the analysis of the power supply system of unmanned aerial vehicle. One of the most important tasks of this system is to ensure the smallest possible losses in order to achieve greater endurance of the aircraft, which means – the ability to complete the mission. The presence of an inactive component of consumed power obviously reduces the efficiency of the entire unmanned aerial vehicle. Considering also that due to the influence of wind, speed changes and other factors, the power system spends a significant amount of time in the transition mode, the impact of this phenomenon becomes even more significant. Thus, the phenomenon of the occurrence of exchange power in the power supply system of an unmanned aerial vehicle is analyzed. One of the most common solutions for unmanned aerial vehicles is the use of a BLDC motor, which is a further development of DC motors and was created with the aim of improving their basic characteristics. This type of engine has gained its popularity due to numerous advantages: high reliability, efficiency, speed and others. The principles of control of the BLDС engine are given. The unmanned aerial vehicle power supply system, built on the basis of a buck converter and a bridge inverter, was analyzed. An equivalent circuit of the converter is built, taking into account the losses in the electric circuit. On its basis the relations for determining the value of exchange power in the power supply system are derived. With the help of these expressions, it is possible to determine the value of the exchange energy at an arbitrary time interval in the real power supply system of the aircraft. A model of the power supply system of an unmanned aerial vehicle with a BLDC engine was built in the Matlab Simulink software environment. A time diagram is obtained, on the basis of which it is possible to draw a conclusion about the content of exchange power in the converter circuit. To minimize this phenomenon, it is necessary to develop a compensation system or an intelligent control system.

Research on Simulation System of Microgrids based on STM32

With the gradual depletion of traditional fossil energy and the increasing demand for electricity, finding new energy sources has become the only way for sustainable development. Microgrid is becoming an important auxiliary power for some developed and developing countries to solve the supply problem of energy system, which can not only effectively improve the overall utilization rate of renewable energy, but also improve the power supply reliability of the main grid. In this paper, the hardware circuit and software control of microgrid simulation system based on STM32 are studied and designed. The main circuit design of microgrid simulation system is based on STM32 single chip microcomputer as the main control core, and the pulse modulation signal SPWM is output through the software program of STM32F103CBT6 single chip microcomputer. The MOS driving circuit provides driving voltage and control signal to drive the inverter bridge to invert DC into AC. The inverter bridge is modulated by SPWM control technology, and the high-frequency signal in AC is filtered by low-pass filtering circuit, and finally the stable AC with a fixed frequency of 50 Hz is the output. By calculating the device parameters of the main control circuit and the full-bridge inverter circuit in the hardware unit circuit, and making appropriate selection of components, the specific model is determined, and finally the circuit design of the whole circuit is completed. The hardware circuit is designed rationally by Altium designer, and the software circuit is programmed by Keil. The influence of SPWM signal output by the circuit on the resistance load and its output waveform is analyzed comprehensively, and the influence of working frequency on the output waveform of the circuit is studied.

A 15-Tiered Multi-Level Inverter Designed for Use in PV and HEV Applications

The basis of this project centers around different topologies and the cascaded H bridge inverter. The primary application of inverters is for businesses and manufacturing needs. The multilevel inverter's distinct arrangement results in decreased output voltage harmonics. Multilevel inverters come in various variations. Cascaded multilevel inverters have acquired a lot of attention in the power industry due to their demand for fewer components. When the level count rises, the harmonic components in the voltage waveform output decline. The inverter with fifteen levels constructed in a cascaded H- bridge configuration utilizes the fewest possible switches. The waveform generated through synthesis becomes more like the desirable waveform as the level rises due to the increasing number of steps producing a staircase wave. By using a small number of switches, the issue of switch losses and power losses can be completely resolved.

New combined impedance‐source network inverter with high gain performance in low shoot‐through and improved quality factors

SummaryIn this paper, a new combined impedance‐source network inverter (CISI) with high voltage gain in low duty cycle is presented. With common ground between the input source and the inverter bridge and a continuous input current, the proposed converter is a suitable choice for renewable energy applications. The duty cycle of the inverter switches is low, leading to a reduction in losses and improving the efficiency. Also, due to the small duty cycle, the modulation index can be increased, and as a result, the quality of output voltages and currents is greatly improved. The proposed circuit has no switch in the input impedance network, and the number of components is reasonable compared to other works. Another advantage of the proposed converter is the low voltage stress on its capacitors and diodes. The proposed circuit is designed and tested at 180 W. The experimental results and the calculated values are close to each other, verifying the accuracy of the analysis.

Design of single cycle current control method based on single-phase full bridge inverter circuit

To achieve accurate control of the large inductive load, a single-phase full bridge inverter circuit topology with a simple structure is proposed. The current control on inductive load is realized by using the single-cycle control method, and the size and direction of the current can be adjusted at any time. The loading part is equivalent to the coil and resistance, the control principle of the circuit is analyzed, and the calculation formula of the duty cycle is calculated. The simulation results show that the designed circuit structure can control the current with a large inductive load

A strategy for improving the SHEPWM commutation speed of CSI through hybrid switches

High-power current source inverters (CSI) usually operate at a low switching frequency to reduce switching loss. To suppress low-order harmonics and simplify filter design, the selective harmonic elimination pulse width modulation (SHEPWM) technique is a feasible common modulation strategy in industrial applications. This paper proposes an operational strategy that uses an H7 current source inverter (H7-CSI) with hybrid switches to perform the SHEPWM technique. On the basis of retaining the conventional H6 inverter bridge, the commutation speed of the CSI is improved by an additional shunt-connected high-performance power switch. The proposed scheme solves the problem that the CSIs built with low-speed switches (such as GTOs) may have difficulty for implementing the setting pulse widths of null states, while further reducing the switching losses at an acceptable cost. In addition, mitigating the influence of overlap-time by optimizing the driving signal of the H6 converter bridge. Finally, simulation and experiments have verified the effectiveness of the proposed CSI scheme.

Research of a High Voltage Generator for Medical Diagnostic X-ray Equipment

A kind of designing scheme of high voltage generator for medical diagnostic X-ray equipment is proposed. A X-ray HV generator, which has output voltage from 60kV to 160kV and tube current from 1mA to 10mA, is developed successfully by applying the technology of LC series resonant soft-switching, high voltage doubling and rectifying, full bridge inverter and pulse width modulation. The topologic structure and simulating result are listed detailed, including high frequency inverter circuit, doubling and rectifying circuit and the controlling system. At last, the experimental data and waveform of the X-ray high voltage generator are presented, verifying the validity of the design scheme.

Design and simulation of an asymmetrical 23-level inverter with modulation Techniques

For medium voltage, high power regulation the Multilevel Inverters (MLI) are attracting industry and academic researchers. MLI generates the desired output in the form of stepped waveforms with reduced harmonics. The MLI is expected to be realised using a variety of traditional topologies. Traditional MLIs have the disadvantage of requiring additional components, which increases the complexity of gate pulse production. As a result, MLI's overall costs will rise. This research proposes a hybrid topology to alleviate these drawbacks. With the increase in the number of steps in output voltage, the number of dc sources, power switching devices, converter cost, and space required is significantly reduced compared to typical MLIs. The design and simulation of a hybrid converter using several types of PWM approaches are covered in this work. This hybrid converter combines a T-Type structure and a half bridge inverter that is back-to-back connected. The proposed construction is designed and simulated by MATLAB Simulink software. The proposed 23 level inverter circuit is designed and simulated by Equal phase angle modulation technique and half height modulation technique, THD is compared.

Solder die attach lifetime characterization of SOT-227 power MOSFET module in a 3-phase inverter under power cycling

Abstract This study aims to assess the power cycling lifetime of the solder die attach of the silicon power metal-oxide-semiconductor field-effect transistor modules in an SOT-227 package in a 3-phase bridge inverter. This goal is achieved through a loose one-way coupling framework that incorporates a thermal computational fluid dynamics model for temperature estimation and a transient thermal-mechanical finite element model that accounts for the time-dependent viscoplastic behavior of the solder die attach through the Anand viscoplastic constitutive model for thermal-mechanical responses assessment. To facilitate an accurate prediction of the solder die attach lifetime during power cycling, a physical lifetime prediction model is constructed through the strain-based Coffin-Manson Eq. together with the experimental lifetime data and the corresponding calculated equivalent viscoplastic strain increments. Furthermore, parametric study via the coupling framework is conducted to examine the effect of cooling, operating, and structural parameters on the solder die attach lifetime, and also to identify the most crucial design parameters. At last, experimental design using a Taguchi method is conducted to seek the optimal level combination of design parameters for enhanced power cycling lifetime of the solder die attach.

Многофункциональная система визуализации на основе лазера и усилителя яркости на парах бромида меди

A multifunctional system meant to image the surface of energetic materials during combustion based on copper bromide vapor gain media is proposed. The system allows quickly implement various methods of active visualization and is based on a high-speed video camera, an illuminating laser, and a copper bromide vapor brightness amplifier. Depending on imaging needs, the main components of the system can be configured as a laser-illuminating system, a single-channel laser monitor, or a laser monitor with synchronous laser illumination. A high-voltage pulsed power supply allows connecting both one laser tube and two at the same time, while switching operating modes can be carried out on- the-fly. The source generates one or two synchronized sequences of high-voltage pulses for pumping gasdischarge tubes with a voltage of up to 6 kV and a frequency of 20 kHz. Due to the use of gas discharge tubes with independent control of temperature parameters, the operating modes with a pump power of 500–700 W for each channel can be realized. To generate pump pulses for laser media, a two-channel thyratron circuit for the direct discharge of storage capacitors were used, charged by a common stabilized voltage source provided by a step-down pulse stabilizer and a pulse shaper for charging storage capacitors based on a bridge inverter. A transistor modulator with adjustable delay lines carries out synchronization of the laser illumination and the brightness amplifier in the mode with synchronous laser illumination with an accuracy of ±1 ns.The experimental data of the system operation in various modes are presented. The imaging results for the surface of mixtures of metal nanopowders during combustion, obtained with various configurations of the laser system, are presented.

A New Non-Isolated Active Quasi Z-Source Multilevel Inverter With High Gain Boost

This paper proposes a three-level diode clamped active impedance source inverter (AIS-TLI) based on the quasi Z-source inverter (qZSI). Apart from having minimal components and the inherent benefits of three-level qZSIs, such as single-stage buck-boost capability, shoot-through (ST) immunity, and continuity of input current, the proposed topology has a higher boost capability and excellent efficiency. In addition, the inverter bridge has a higher modulation index, which improves the quality of the output waveform and necessitates less inductance. The proposed topology provides common ground between input and output terminals, which effectively eliminates leakage current in PV-powered single-phase systems. This paper describes the different operating modes principle, dynamic analysis, steady-state analysis, and parameter selection instructions for the proposed in-depth. Furthermore, the suggested inverter’s benefits and limitations are compared to the traditional (q)ZSIs and some other AIS-TLIs. Finally, modeling and experimental results are used to confirm the effectiveness of the suggested topology.

Nonisolated Dual-Output Single-Phase Boost Inverter With Reduced Active and Passive Components

This article proposes a nonisolated dual- output single-phase boost inverter with reduced active and passive components. The suggested inverter can serve two single-phase ac loads independently like two full-bridge inverters, but owing to the use of a pair of three-switch legs in the inverter bridge, it has a 25% reduction in active switches. The proposed inverter is capable of obtaining a boost output voltage while employing fewer passive components compared to the traditional impedance source inverter. And the high-frequency current commutation problem of diodes in the traditional split-source inverter is solved by replacing the diodes with two complimentary switches. A hybrid sinusoidal and constant pulsewidth modulation control strategy is elaborated, which enables the proposed inverter to operate in equal frequency mode and different frequency mode. Comprehensive working principles, modulation strategy, steady-state analysis, and parameter design guideline are introduced, both simulation and experimental results are presented to confirm the characteristics of the proposed topology.

Application of PCCS Method to PV Generation System with Half Bridge Inverter

A Power Conditioning System (PCS) for a PV power generation system obtains the maximum power from a photovoltaic (PV) array by Maximum Power Point Tracking (MPPT), but losses in the inverter are a factor in lowering the power obtained by the MPPT. The generation of harmonic currents is also a problem for PCS. This paper proposes the application of the Peak Current Control Switching (PCCS) method in PCS for PV Generation System using a half bridge inverter. The half bridge inverter improves efficiency by reducing the number of switching elements and further suppresses harmonic currents by controlling them using the PCCS method. In this paper, a comparative simulation of the conventional Hysteresis Current Control (HCC) method and the proposed PCCS method is performed using a half bridge inverter. The results of harmonic analysis and comparative simulation of total harmonic distortion (THD) show that the PCCS method generates harmonic components near the switching frequency, and that the proposed PCCS method always has a lower distortion rate than the conventional HCC method.

Design Methodology of Series Resonant Half Bridge Inverter for Induction Cooker

Design Methodology of Series Resonant Half Bridge Inverter for Induction Cooker

Efficiency Considerations of LLC Resonant Converter for Induction Heating Application

Due to the high efficiency, high power density and low EMI provided by the LLc resonant converter, it has been widely used by researchers in many fields such as induction heating (IH). This converter is based on a resonant circuit consisting of a capacitor (Cr) and two inductors Lr, Lm operating in wide output load regulating ranges for the purpose of achieving good efficiency for very high power systems using a high operating frequency. This paper aims to present a half-bridge LLC resonant converter based on power supplies for IH applications. The analysis contains five components: half bridge inverter, resonant tank, high frequency transformer, rectifier and coil. The switching bridge generates a square waveform to excite the LLC resonant tank, which will produce a resonant sinusoidal current which is transferred to the secondary of the converter through a high-frequency transformer. as it scales the voltage up or down according to the output requirements. The load represented by the equivalent circuit of the coil and work-piece is fed by the current transformed by the rectifiers. This paper provides an improved knowledge of the control of the output power for high-temperature applications through numerical simulation Considering that the load parameters and resonant frequency vary substantially throughout the system operation. The results of testing demonstrated that the proposed scheme and assembly has good efficiency, and it is well suited for magnetic induction heating systems.