Diode Clamped Inverter Research Articles

Solar Based Multilevel Inverter f o r BLDC Motor Drive

The BLDC motor is widely utilized in high power and low voltage applications because to its simple construction, great efficiency, low maintenance requirements, and low cost .Furthermore, considering their size, they have a lot of torque and power output. The BLDC motor is powered by an alternating current source and is operated straight from the AC supply port, despite being a DC motor in this case. The main drawback is that any disruptions in the source will have an impact on the applications that use BLDC motors in the industrial context. So, to avoid this, there should be a converter and an inverter intermediary between the motor and the source. One of three methods can be used to drive the BLDC motor. 1. Two-level inverters based on pulse width modulation (PWM). 2. An multiple-level working inverter. 3. A multilevel inverter with neutral clamping. Using a multicarrier PWM technique, the suggested inverter may lower the output signal's harmonic content. It is capable of generating very good motor currents. In this instance, a three-level diode clamped multilevel inverter can be used to accurately control the speed of a BLDC. This study's primary goal is to demonstrate how to run a BLDC drive with an inverter to lower harmonics. A diode clamped multi-level inverter is a device that converts voltage to current. An improved version of this strategy is provided by this research. Using the MATLAB Simulink software tool, one can assess the system's overall effectiveness by simulating the neutral clamp multilevel inverter-based drive system's functioning. In the event of a power outage, the entire application will cease to function and generate output. Under order to increase the output and supply reliability of power, renewable energies must be used under these circumstances. There are many renewable energy sources available; however solar photovoltaic systems are the better option because of their benefits over traditional power sources. A diode clamped multi-level inverter was used. A diode clamped multi-level inverter was used to drive the BLDC.

Formation of the Spectral Composition of the Output Voltage of Converters for Nuclear Magnetic Resonance

In this paper, we consider the construction of an asynchronous control system for semiconductor converters for nuclear magnetic resonance. The relevance of research in this direction, main problems that arise during the construction of these systems are shown. Derived the mathematical model of the inverter, on the basis of which a control system with asynchronous pulse-width modulation is constructed. Proposed an equivalent converter circuit with a constant structure, constant parameters, and an equivalent EMF generator. Established correspondence between the equivalent circuit of the converter and its mathematical model in the form of differential equations. On the basis of mathematical equations, a structural diagram of the converter with a control system was developed and the principle of operation of the device was described according to it. To develop an algorithm for the control system, the dependence of the frequency change relative to the resonant frequency on the phase shift between the current through the filter and the voltage on the antenna circuit is determined. For which the model was built in Simulink and the corresponding simulation was carried out. Numerical dependences of reference signal frequency change and phase shift were obtained. The increase in efficiency of device for nuclear magnetic resonance is considered due to the use of multilevel inverters with tuning the frequency of operation to the frequency of the resonant circuit. Simulation of a three-level diode-clamped inverter showed that when the capacitance of the resonant circuit changes and, therefore, the resonant frequency of the circuit, the input current increases. The work obtained specific numerical dependencies. Time diagrams of voltages and currents on the main elements of the converter are given, which illustrate the implementation asynchronous pulse-width modulation in the control system. After working out the automatic frequency control algorithm, the increase in current consumption can be leveled off. The simulation results also show that it is possible to reduce the amplitude of the third harmonic. The disadvantages of the proposed system include the fact that the frequency of the converter is adjusted at each subsequent period of its operation. At the same time, the parameters of the filter can change again, which leads us to believe that adjusting the frequency will never give a 100% result, but will only allow to get as close as possible to the set parameters of the sounding signal. The work also indicates that it is possible to improve the spectral composition of the probing voltage generated by the converter by using more levels of a diode-clamped multi-level inverter. However, increasing the number of levels reduces the action speed of the system and complicates the control system itself. Therefore, the need to maintain a balance between the number of levels of the inverter and the complexity of the system is indicated.

Analysis and mitigation of PQ disturbances in grid connected system using fuzzy logic based IUPQC

Renewable energy integration introduces grid instability due to variable and intermittent sources like solar and wind, impacting reliability. This paper provides a thorough discussion of recent advancements and emerging trends in grid-integrated wind energy systems (GIWES) and grid-integrated solar energy systems (GISES). More than 70 research articles have been rigorously assessed and listed the technological and economic challenges. The increase in installations of grid-Integrating systems gives rise to challenges like as grid strain, peak shaving impacts, unpredictability of renewable energy sources (RES), and power quality disturbances. A variety of custom power devices, such as dynamic voltage restorers (DVR), static synchronous compensators (STATCOM), active power filters (APF), and unified power quality conditioners (UPQC), have gained popularity in response to these challenges. Among the various challenges, power quality disturbances, including voltage sag, swell, current and harmonics pose significant issues. To address these disturbances this work present a novel approach utilizing fuzzy logic (FL) to develop multi-feeder interline unified power-quality conditioners (MF-IUPQCs). The MF-IUPQC has three legs and three levels, each of which has four diode-clamped inverters. Switching is carried out through the use of space vector pulse width/duration modulation (SVPWM). Total harmonic distortion (THD) induced by nonlinear loads is reduced by the FLC-based MF-IUPQC, which also improves dynamic performance and offers a smooth DC-link voltage. The proposed control mechanism is implemented using MATLAB/Simulink. The fuzzy-based controller is compared to the industry-standard proportional-integral (PI) controller to determine its efficacy. Among them, the MF-IUPQC based on FLC delivers the smoothest voltage profile and the lowest THD.

A Comparative Study on the Performance of the Induction Motor with Fuzzy-Based Power Converters

This study investigates the influence of load conditions on grid voltage stability and the performance of a proposed compensator, encompassing a 1.5 hp 4-pole induction motor (IM) exposed to grid voltage disturbances. Through rigorous grid current analysis, our research demonstrates the effective mitigation of total harmonic distortion (THD) without necessitating passive filters. The comprehensive study covers multiple facets, including control strategy optimization, fine-tuning of control parameters, component ratings, output voltage analysis, operating principles, pulse width modulation, and the integral role of the fuzzy logic controller. Specifically, it underscores the significant impact of a Predictive Torque Control-based Diode Clamped Inverter in enhancing the dynamic and steady-state performance of the IM. The research delves into traditional PTC control methods and advanced techniques, such as fuzzy and evolutionary control, addressing the persistent challenge of reducing torque ripple under varying load conditions. By implementing model prediction control-based DCI, our method achieves rapid torque response without compromising the motor’s stator characteristics. Utilizing MATLAB’s environmental package, we thoroughly evaluate motor performance across diverse scenarios, encompassing stable, and rapid load changes. Despite inherent winding impedance challenges, our proposed approach consistently delivers satisfactory output responses, contributing to a more efficient, and resilient IM performance under diverse operating conditions.

Efficiency and Power Loss Distribution in a High-Frequency, Seven-Level Diode-Clamped Inverter

The paper presents efficiency and power loss analysis in a high-frequency, seven-level diode-clamped inverter (7LDCB). The inverter is composed of four-level (4L) diode-clamped branches based on MOSFET transistors and Si Schottky diodes. The range of DC-link voltages enables the operation of the inverter in connection with a single-phase power grid. The tested inverter can be controlled using various modulation concepts that affect its parameters, but also energy losses. Carrier-based modulation, which may be useful in a few applications, is compared to selective modulation based on the state machine (SM-based) algorithm. The article demonstrates the efficiency level of the inverter as well as the influence of the modulation method and switching frequency on the efficiency and loss distribution in semiconductor devices. The article also shows the hardware implementation of a complex modulation algorithm based on selective switching states used to maintain voltage balance on three DC-link capacitors. Redundant switching states allow the generation of the same voltage but with the use of a selected DC-link capacitor. This makes it possible to balance the DC-link voltage with the load current. The article presents experimental results, which show the advantage of using the modulation method with selective switching states. First, it allows for equalizing the loading of DC-link capacitors. The second advantage is a more uniform distribution of losses in semiconductor components.

Power Conversion Systems with Synchronous Control and Regulation on the Base of Powerful Diode-Clamped Inverters via Pulse Width Modulation

This article provides a brief overview of the development and dissemination of the method of synchronous multi-zone pulse-width modulation (PWM) in relation to the regulation of diode-clamped inverters which are the main executive elements of the medium-power and high-power adjustable speed electric drives. It is shown that the modified schemes and algorithms of synchronous multi-zone PWM, applied for control of diode-clamped inverters, assure providing minimization of the common-mode voltage in systems, as well as continuous synchronization and symmetry of the base phase and linear voltages in drive systems on the base of diode-clamped inverters over the entire control range. There are no even harmonics and subharmonics in the spectra of the phase and line-to-line voltages of three-phase and six-phase drive systems, which helps to reduce losses in systems and increase the efficiency of their operation. As a result of a comparative analysis of the integral spectral characteristics of the main voltage waveforms of adjustable speed drives based on diode-clamped inverters, recommendations are formulated for the rational choice of schemes and algorithms of synchronous multi-zone PWM for the relevant systems and installations, depending on their operating modes.

A Comparative Review of Three Different Power Inverters for DC–AC Applications

This paper presents a comparative review of three different widely used power inverters, namely the conventional six-switch inverter; the reduced switch count four-switch inverter; and the eight-switch inverter. The later inverter can be reconfigured as a neutral-point diode-clamped inverter at the failure of one inverter leg. The three power inverters are compared and discussed with respect to cost, complexity, losses, common mode voltage, and control techniques. The paper is intended to serve as a guide regarding selecting the appropriate inverter for each specific application. Simulation results are presented to demonstrate the performance of the three power inverters, followed by a comprehensive comparison between the three power inverters.

Performance analysis of FOC space vector modulation DCMLI driven PMSM drive

The effectiveness of a permanent magnet synchronous motor (PMSM) drive managed by an automatic voltage regulator (AVR) microcontroller using field oriented control (FOC) with space vector modulation (SVM) and a diode clamped multilevel inverter (DCMLI) is investigated. Due to its efficacy, FOC would be widely implemented for PMSM speed regulation. The primary drawbacks of a 3-phase classic bridge inverter appear to be reduced dv/dt stresses, lesser electromagnetic interference, and a relatively small rating, especially when compared to inverters. PMSMs have a better chance of being adopted in the automotive industry because of their compact size, high efficiency, and durability. The SVM idea states that an inverter's three driving signals are created simultaneously. Using MATLAB simulations, researchers looked into incorporating a DCMLI with a resistive load on an AVR microcontroller. Torque, current, and harmonic analysis were evaluated between the SVM and the inverter-driven PMSM drive in this research. In comparison to the prior art, the proposed PMSM drive has better speed and torque management, less output distortion, and less harmonic distortion.

Performance Analysis of Conventional IPMSM and NCPM Based IPMSM

This paper proposes a NCPM (Nano-composite coated permanent magnets)-based IPMSM (Interior Permanent Magnet Synchronous Motor) electric drive system, especially applicable for electric vehicles (EV). For an EV, an increase in the “T/A (torque per ampere)” condition is highly recommended, as it directly affects the maximum distance run by EV on a single charge. Due to NCPM, a substantial increase in magnetic flux intensity, resistance to corrosion and Curie temperature are observed. As a result, the proposed drive clearly exhibits a higher power to weight ratio. Also, it is capable of delivering higher T/A to the drive system without any considerable change in two important factors of EV: (1) mass and volume of the drive system (2) battery capacity of the drive system. Moreover, NCPM performance is less susceptible to temperature variation, which makes it an appropriate candidate for vehicular applications, where temperature inconsistency could be a common issue during working conditions. Also, NCPM-based IPMSM offers a quicker speed response than conventional IPMSM, thus providing higher acceleration, which is one of the important performance factors for vehicular applications. A vector controlled mathematical model of IPMSM and NCPM-based IPMSM is tested for various speed commands. Also, the NCPM-based IPMSM, in the proposed configuration, is fed from a three-level DCMLI (diode clamped multi-level inverter), as the drive system is considered for medium to high power applications. A comparative performance analysis is carried out between the proposed drive system and a conventional IPMSM-based drive system using MATLAB/SIMULINK to indicate the efficacy of the proposed configuration.

Capacitor voltage unbalance minimization for three-phase five-level diode-clamped inverter using hexagonal hysteresis space vector modulation

Capacitor voltage unbalance minimization for three-phase five-level diode-clamped inverter using hexagonal hysteresis space vector modulation

DTC Based on Five-level SVM with Balancing Strategy of Sensorless DSSM

This paper presents a direct torque control based on multilevel space vector modulation of a double star synchronous machine operating without speed sensor. Each star of the machine is supplied by a five-level diodeclamped inverter. This topology of multilevel inverters represents one of the most interesting solutions to increase voltage and power levels and to achieve high quality voltage waveforms. However, a very important issue in using diode-clamped inverters is the ability to guarantee the stability of the DC-link capacitor voltages. To overcome this problem the multilevel space vector modulation equipped by a balancing strategy is proposed to suppress the unbalance of DC-link capacitor voltages. For achieving high performances control of the multiphase drive, the proposed control method needs accurate information about rotor position and rotor speed. To this end, they are estimated by using Luenberger observer.

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.

Power quality improvement of microgrid fed electric ship using fuzzy controlled multi-pulse/multi-level converter-based VFD

This paper investigates a harmonic mitigation technique for modern electrical propulsion ships (EPS) microgrids (MG) using a fuzzy controlled multi-pulse rectifier (MPR) and multi-level inverter (MLI)-based variable frequency drive (VFD). In this paper, the proposed MPR-MLI-VFD system is studied using different-pulses rectifiers and different-level inverter-based VFD to achieve proper mitigation of the harmonics in the main generating power system of the ships within the marine classification society's limitations for harmonics. This is achieved using a proposed low harmonic multi-pulse rectifier based on zigzag transformers. Moreover, the voltage harmonic distortions at propulsion motor feeder buses are minimised using the proposed MLI. A simple fuzzy logic control system is proposed for the VFD speed control. The voltage balancing control system for the diode clamped multi-level inverters is implemented using a fuzzy control system. MATLAB/Simulink is used for the simulation and validation process.

Reduced Common Mode Multilevel Inverter Strategy in Photovoltaic Systems

Now-a-days, non-conventional energy sources are playing a vital role in the generation of electrical energy. This is due to the disadvantages in the conventional sources like pollution, non-availability of the resources, greenhouse effect. Hence more concentration is made by the researcher’s on these non-conventional sources so called as renewable energy sources. These renewable sources are used with the converters along with filters to give the best output. In this work, we are focusing on the renewable energy called solar energy and hence the converter is inverter in this case. Basically we have conventional inverters as well as multilevel inverters. Multilevel inverters are basically classified into three types and they are cascaded H-bridge multilevel inverter, diode clamped multilevel inverter, flying capacitor multilevel inverter. Among these cascaded multilevel inverter as many advantages like reduced number of components. This advantage is being used in this work and is simulated by using MATLAB.

Multirate Predictive Control for Diode Clamped Inverters with Data-Based Learning Implementation

Diode clamping is a widely used topology for power inverters due to the low number of components, low cost, and general efficiency of the circuit, but its main drawback is the difficulty in controlling a multilevel configuration. For that, finite-control-set model predictive control was chosen, as it is a multivariable optimal controller that takes into account constraints and deals with multiple objectives. However, it has high computational burden and its control solution is held constant during the sampling period if not using modulation. This work first proposes a multirate enhancement for this control technique to address the latter issue, and then uses a novel learning method to allow the online implementation and overcome the high computation time. This method is tested in simulation in a three-phase, five-level diode-clamped inverter. Comparisons and performance gains of the multirate technique are provided.

An experimental realization of improved grid integrated multilevel inverter based PV systems with MPPT

AbstractThis research work explains a sliding mode controller‐based multilevel inverter for grid integrated photovoltaic power structure. A gravitational search algorithm based on maximum power point tracking has also been discussed for optimal photovoltaic power achievement. Moreover, a two‐stage cascaded interleaved boost converter has been employed, which provides minimised voltage/current ripple, higher current/power density, better efficacy, faster response, and reduced electromagnetic interference as major benefits. The multilevel inverter's proposed constant frequency‐based sliding mode controller provides better transient responses, high photovoltaic power tracking, and good robust behaviour under changing operating conditions. The proposed sliding mode controller has a fixed frequency operation and has low reactivity to parameter divergence. The proposed multilevel diode clamped inverter for grid integrated photovoltaic system provides a reduced number of components and a power rating. The gravitational search algorithm‐based swarm technique as a maximum power point tracking provides high convergence velocity, better accuracy, and good local search capability. The experimentation was carried out to implement control algorithms using the dSPACE platform. The designed multilevel inverter system with proposed control provides average 89.2% inverter efficiency under variation of sun insolations.

A grid-tied PV-fuel cell multilevel inverter under PQ open-loop control scheme

Power generating entities’ connection to utility grids requires power converters to achieve high efficiency and low injected current harmonic distortion. The control of the power converter plays a crucial role in the grid-tied power converter’s performance. Various control techniques for grid-tied inverters ranging from classical to intelligent are introduced in several exist. Evaluating the current state and trend in grid-tied power inverters and related control methods, research shows that most works in this area focus on grid integration using the close-loop and other advanced control approaches. This is because these control methods are preferred since they provide adequate performance in case of uncertainties in the system. This investigation can aprove that PQ open-loop control technique can operate sufficiently and cost-effectively in grid-tied renewable and alternative power systems under normal operating conditions. Hence, this paper aims to assess the performance of a centralized single-stage grid-tied three-level diode clamped inverter connected to a PV-Fuel cell unit. An active and reactive power open-loop control scheme is employed to operate the inverter and achieves a current harmonic distortion below 5%. The system comprises a 150 kW/700 V PV, a 150 kW/1400 V fuel cell, a 265 kW multilevel inverter operating at a rated voltage of 415 V, and an LCL filter. Two operating scenarios are adopted to investigate the system’s responses further. In the first scenario, a local load of 509.2 kW is supplied from the PV-fuel cell inverter. The load also receives the grid’s power to meet the demand as the PV-fuel cell inverter provides only 265 kW. Whereas in the other scenario, the PV-fuel cell unit provides power to supply a local load while transporting the surplus to the grid. The results reveal the developed model’s good performance with a current harmonic distortion of 0.33%.

Hybrid Multi-Level Source Inverter Design and Validation in Solar Photo-voltaic Renewable Energy System

This paper proposes the hybrid multi-level source inverter in light of staggered coordinated framework for boosting photo voltaic power. Hybrid multi-level inverter (MLI) proposed to design less number of switches compare with other MLIs of diode clamped multi-level inverter, the smallest number of switches are required to accomplish the highest steps in staircase AC output voltage. HMLIs additionally include variable info voltage and carries out load guideline to keep up with consistent result voltage. The HMLIS intends to operate in multiple stages during shoot through stage exchanging beat width (PWM) adjustment keeps up with to work in buck and lift mode. The activity of proposed work implemented in MATLAB and discuss effectiveness with diminished sounds took care of inverter operation. Model of converter is planned and accomplished the most extreme effectiveness of 95.4% as information voltage goes from 10-60 volts and result of half breed staggered source inverter keeps up with steady of 230v dc. Trial results approve the exhibition of proposed half and half staggered source inverter for exchanged mode power supplies utilized in PC.

Multi-phase inverter-controlled induction machine at varied rotor parameters

<p>This paper presents a step-wise modelling of a symmetrical six-phase induction machine driven by a six-phase diode clamped multi-level inverter at a varying rotor resistance and motor inertia. The machine drive process was considered in two stages. The first stage presents the dynamic behavior of the machine when a load torque of 0 Nm and 100 Nm is applied at a varied rotor external resistance value of (0.8 and 3.2) Ω with constant motor inertia. The second stage showcased the variations in the speed, electromagnetic torque and rotor current when motor inertia is varied at (0.5 and 1.5) Kg-m2 with rotor resistance held constant. A six-phase five-level diode clamped converter phase displaced by sixty degrees with a modulation index of 0.8 was modeled to drive the poly-phase machine at a reduced %THD. All machine models were simulated in MATLAB 7.11. The simulation results showed that reduced oscillations in rotor current, motor speed and torque pulsations were achieved at a varied external rotor resistance and motor inertia.</p>

Diagnosis and localization of fault for a neutral point clamped inverter in wind energy conversion system using artificial neural network technique

Introduction. To attain high efficiency and reliability in the field of clean energy conversion, power electronics play a significant role in a wide range of applications. More effort is being made to increase the dependability of power electronics systems. Purpose. In order to avoid any undesirable effects or disturbances that negatively affect the continuity of service in the field of energy production, this research provides a fault detection technique for insulated-gate bipolar transistor open-circuit faults in a three-level diode-clamped inverter of a wind energy conversion system predicated on a doubly-fed induction generator. The novelty of the suggested work ensures the regulation of power exchanged between the system and the grid without faults, advanced intelligence approaches based on a multilayer artificial neural network are used to discover and locate this type of defect; the database is based on the module and phase angle of three-phase stator currents of induction generators. The proposed methods are designed for the detection of one or two open-circuit faults in the power switches of the side converter of a doubly-fed induction generator in a wind energy conversion system. Methods. In the proposed detection method, only the three-phase stator current module and phase angle are used to identify the faulty switch. The primary goal of this fault diagnosis system is to effectively detect and locate failures in one or even more neutral point clamped inverter switches. Practical value. The performance of the controllers is evaluated under different operating conditions of the power system, and the reliability, feasibility, and effectiveness of the proposed fault detection have been verified under various open-switch fault conditions. The diagnostic approach is also robust to transient conditions posed by changes in load and speed. The proposed diagnostic technique's performance and effectiveness are both proven by simulation in the SimPower /Simulink® MATLAB environment.