DC Voltage Source Research Articles

Simulation and analysis of T-PUC9 inverter fed single phase induction motor application

This paper presents the simulation and analysis of a Nine-Level T-Type Packed U-Cell (T-PUC9) Inverter fed single phase Induction Motor. This inverter includes a T-type neutral point clamped (NPC) pole, two identical DC voltage sources and a one half-bridge module. It employs a Multiple pulse width modulation (PWM) scheme for generating the pulses for all the eight switches to synthesis the desired nine level voltages namely 2Vdc, 1.5Vdc, Vdc, 0.5Vdc, 0, -0.5Vdc, -Vdc, -1.5Vdc and -2Vdcwhich resembles a nearly sinusoidal wave owing to the rise in the number of steps. Due to its low-level harmonic distortion in the output it is used in industrial applications. The simulation model of the presented inverter has been developed for a single-phase induction motor application for a two identical DC voltage sources of 110V each using the MATLAB Simulink platform. The theoretical predictions and the performance of the Nine-Level T-Type Packed U-Cell (T-PUC9) Inverter fed single phase induction motor have been successfully validated with the help of simulation results.

A Universal Lookup Table-Based Direct Torque Control for OW-PMSM Drives

For open-winding permanent magnet synchronous motor (OW-PMSM) system with two isolated dc voltage sources, the distribution of voltage vectors (VVs) is different under different dc-link voltage ratios. In this letter, a universal lookup table (LUT) based direct torque control (DTC) strategy is proposed for OW-PMSM drives under different conditions of the dc-link voltage ratio. The distribution criterion of VVs under various dc-link voltage ratios is analyzed and the VVs are assigned to different regions by designing a generalized region division scheme. A universal LUT is established to realize the selection of required VV in the DTC strategy. Experimental results validate the effectiveness of the proposed universal LUT-based DTC strategy for the OW-PMSM system with different voltage ratios.

Implementasi DC-DC Boost Converter Menggunakan Arduino Berbasis Simulink Matlab

Direct current (dc) voltage sources are one of the voltage sources most widely used for various purposes. Dc voltage can be obtained from a dc generator or by converting an ac voltage into a dc voltage using a power converter. There are several dc voltage levels that are commonly used by electrical and electronic equipment. To get a dc voltage that can be used for various equipment, then a dc voltage source must be varied according to the required. One way to get a variable dc voltage is to use a dc-dc converter. This research proposes a dc-dc boost converter that can increase the dc voltage with varying outputs. The boost converter is proposed using Arduino Uno as a controller with an input voltage of 12 volts. The converter output voltage regulation is implemented through Arduino programming using Matlab simulink. The experimental results show that the boost converter designed in this study has worked well as intended. This can be seen from the boost converter output voltage which is in accordance with the reference voltage entered in the Matlab simulink program

Topology and Control of Four-Quadrant Dual-DC-Port Dual-Buck Inverters For Semi-Two-Stage DC–AC Power Conversion

A method to derive topologies of four-quadrant dual-dc-port dual-buck inverter (DDP-DBI) is proposed in this article. A new family of DDP-DBIs is obtained by replacing one of the switching legs in a four-quadrant dual-buck half-bridge switching cell with a dual-input buck type switching leg. With the proposed DDP-DBIs, both the low voltage dc source and the high voltage intermediate dc-bus can be used as the inputs of the inverter. Therefore, in comparison with the conventional two-stage dc-ac power system, a semi-two-stage dc-ac power conversion system with reduced power losses and enhanced conversion efficiency is achieved. A unipolar sinusoidal pulse width-modulation strategy is presented for the DDP-DBI. In each line cycle, all the power devices and filter inductors only operate within half line cycle, and only one active switch is operated at high frequency. Moreover, no freewheeling current flows through the body diodes of the active switches. As a result, the conversion efficiency of the overall dc-ac power conversion system is improved. Operation principles, characteristics, modulation and control strategies of one of the proposed DDP-DBI are analyzed in detail. Effectiveness and feasibility of the proposed DDP-DBI are verified with experimental results.

Reduced voltage stress hybrid multilevel inverter using optimised predictive control

This study presents a hybrid multilevel inverter (HMLI), capable of generating 19 voltage levels using a single DC voltage source. The peak inverse voltage of all the switches is restrained within the input DC source voltage in the proposed HMLI, which requires only three capacitors and 15 switches to achieve 19 voltage levels. In the proposed HMLI, one of the capacitors is self-balanced, while the other two capacitors are balanced using a modified finite control set model predictive control (MFCS-MPC). The proposed MFCS-MPC reduces the computation time considerably without affecting the performance of the system. The proposed HMLI is compared with some other HMLI topologies to show its merits in terms of active and passive components. Finally, the steady-state and dynamic performance of the proposed topology and its control algorithm is validated through simulation and experimentation for a 1 kW prototype.

Switched‐capacitor‐based boost multilevel inverter topology with higher voltage gain

This study proposes a new switched-capacitor-based multilevel inverter topology with a single dc voltage source. The proposed topology finds its suitability for renewable energy applications with low voltage. Seven-level (7L) output voltage is achieved across the load with triple-voltage gain employing 2 capacitors and 12 switches. Self-voltage balancing of capacitor voltages, parallel operation of capacitors during discharging mode, reduced voltage stress, and bipolar output voltage generation without using backend H-bridge are the major features of the proposed topology. Furthermore, a generalised structure of the proposed topology has also been discussed here. A comparison with other similar topologies with single-source 7L configuration has been carried out to show the advantages of the proposed topology with reduced switch count. Experimental results have been provided to verify the performance of the proposed topology with different operating conditions.

Analysis of the harmonic composition of the rectified voltage at the asymmetry of the secondary system of windings with different turns in converter

The use of integrated transformer converters of the number of phases, in which the EMF phase system at the input of bridges is formed by the geometric addition of the EMF components of individual windings, expands the scope of application of DC voltage sources with ripple frequency. With the symmetry of the transformer converter of the number of phases included in the valve bridges, each ripple of the rectified voltage of the integrated rectifier contains m ripples of exactly the same amplitude and duration, containing the corresponding composition of harmonics. However, when designing such integrated rectifiers, there is a problem of ensuring an acceptable level of symmetry of the multiphase EMF system. This is due to the inability to implement the required ratios between the numbers of turns due to their discreteness. This paper presents studies of the analysis of harmonics of rectified voltage with an asymmetry formed by a secondary system of multi-turn windings for an eight-pulse rectification scheme.

New modular high‐voltage pulse generator based on SEPIC converter for electroporation applications

High-voltage (HV) pulses are widely used in many applications. This study proposes a new HV unipolar pulse generator based on Single-Ended Primary-Inductance Converter (SEPIC) for electroporation applications. The converter in the proposed pulse generator operates in discontinuous conduction mode with continuous input current. The proposed structure uses voltage-boosting modules that are fed from a relatively low voltage DC source with a reduced number of semiconductors. The number of semiconductor devices and the voltage stress across them are important issues for HV pulse generators. The proposed approach does not have any chopping switches at the output stage, which greatly affects cost, efficiency, and system control. The employed semiconductor switches and diodes in the proposed topology have low voltage and current stresses, so the structure can be implemented with the market-available semiconductor technology. Mathematical analysis is presented along with a full design of the system components. Finally, simulation and experimental results are presented to validate the proposed concept.

Operational Limits of a Cascaded Dual-Output Multilevel Converter Using Model Predictive Control

This article proposes a modified cascaded dual-output multilevel converter with a reduced number of power switches. The proposed converter can provide independent multilevel voltages across its dual-output ports, which makes it distinct when compared with the existing topologies. The mathematical model of the converter is developed for two converter cells with two output ports and is incorporated in a finite control set model predictive control algorithm for controlling the dual-output currents. Due to an inherent restriction, the converter output ports can operate independently, only during certain operating conditions. Therefore, converter operational limits in terms of voltage amplitude range are investigated for its output ports operating under various modes, such as different amplitude, different frequency, and different phase angle. The developed model is simulated for all these modes, and the operational limits of the proposed converter are obtained based on the distorted output currents. The effects of unequal dc source voltages on the operational limits are also analyzed. The determined operational limits ensure that the converter output ports operate independently without any current distortion and guarantee a safe operation. Finally, the operation of the proposed converter under different operating conditions is validated using simulation and experimental results.

A Novel Switched-Capacitor Multilevel Inverter Topology for Energy Storage and Smart Grid Applications

The recent advancement in the application of the internet of things in the smart grid has led to an industrial revolution in the power industry. The Industry 4.0 revolution has already set in, allowing computers to interact for an efficient and intelligent approach in solving smart grid issues. multilevel inverters (MLIs) are an integral part of the smart grid system for integrating the distributed generation sources and storage energy systems into the smart grid. It attracted attention in industrial applications as they can handle high power and high voltage with an inherent feature of superior output voltage waveform quality. Moreover, its variant, the switched-capacitor MLI (SCMLI), has the added benefit of lesser DC supply requirement. In this paper, a switched-capacitor multilevel inverter topology has been proposed, which can operate in symmetric and asymmetric mode. The proposed SCMLI generate thirteen and thirty-one level output voltages for symmetric and asymmetric selection of DC voltage sources, respectively. The proposed SCMLI has a smaller number of switching devices for a given output voltage level as compared to other recently proposed topologies. A thorough comparison is presented with the recently proposed topologies on several parameters, including cost function. To validate the proposed topology, symmetric and asymmetric cases were simulated using Matlab® 2018a and the results were verified using an experimental hardware setup.

Multi-Port DC-DC and DC-AC Converters for Large-Scale Integration of Renewable Power Generation

Numerous research studies on high capacity DC-DC converters have been put forward in recent years, targeting multi-terminal medium-voltage direct current (MVDC) and high-voltage direct current (HVDC) systems, in which renewable power plants can be integrated at both medium-voltage (MV) and high-voltage (HV) DC and AC terminals; hence, leading to complex hybrid AC-DC systems. Multi-port converters (MPCs) offer the means to promote and accelerate renewable energy and smart grids applications due to their increased control flexibilities. In this paper, a family of MPCs is proposed in order to act as a hybrid hub at critical nodes of complex multi-terminal MVDC and HVDC grids. The proposed MPCs provide several controllable DC voltages from constant or variable DC or AC voltage sources. The theoretical analysis and operation scenarios of the proposed MPC are discussed and validated with the aid of MATLAB-SIMULINK simulations, and further corroborated using experimental results from scale down prototype. Theoretical analysis and discussions, quantitative simulations, and experimental results show that the MPCs offer high degree of control flexibilities during normal operation, including the capacity to reroute active or DC power flow between any arbitrary AC and DC terminals, and through a particular sub-converter with sufficient precision. Critical discussions of the experimental results conclude that the DC fault responses of the MPCs vary with the topology of the converter adopted in the sub-converters. It has been established that a DC fault at high-voltage DC terminal exposes sub-converters 1 and 2 to extremely high currents; therefore, converters with DC fault current control capability are required to decouple the healthy sub-converters from the faulted one and their respective fault dynamics. On the other hand, a DC fault at the low-voltage DC terminal exposes the healthy upper sub-converter to excessive voltage stresses; therefore, sub-converters with bipolar cells, which possess the capacity for controlled operation with variable and reduced DC voltage over wide range are required. In both fault causes, continued operation without interruption to power flow during DC fault is not possible due to excessive over-current or over-voltage during fault period; however, it is possible to minimize the interruption. The above findings and contributions of this work have been further elaborated in the conclusions.

Design and Analsyis of 31-Level Asymmetric Cascaded H-Bridge Multilevel Inverter with Reduced Number of Switches

A new multilevel inverter with less no of power switches is proposed. This is based on cascaded H-bridge topology. The design and analysis of 31-level reduced switch inverter with different modes of operation are presented in this paper. The proposed inverter is asymmetric in nature and it uses unequal DC voltage sources. PD-PWM modulation technique has been used here to get proper switching. The proposed idea has been validated through simulation and the received results provides better efficiency, less low order harmonics and less switching losses.

A new generalized cascade multilevel converter topology and its improved modulation technique

SummaryIn this paper, a basic unit for the nine‐level converter is firstly presented. Then, a new developed basic unit topology for the multilevel converter is proposed. This topology comprises several bidirectional and unidirectional switches along with dc voltage sources. In order to increase the number of generated levels, a cascade topology based on the series connection of developed basic units is studied. Due to the extensive nature of the presented cascade multilevel converter, the optimization analysis is presented for generating the maximum number of levels with minimum numbers of IGBTs, drivers, dc voltage sources, and voltage on switches. All required mathematical analysis consisting of switching losses, conduction losses, and voltage on switches is illustrated. In order to indicate the merits of the proposed multilevel converter, comparison results are provided. It is shown that the presented topology uses the least numbers of power electronic components. Also, the voltage on the switches in the presented cascade topology is low. For controlling the switches, a modified triangular carrier signal for dual pulse generation is proposed. The performance of the proposed multilevel converter is proven with experimental results of a typical 25‐level converter.

Voltage Enhancement In a Distribution Power System With SMES Based DVR

This Power quality is one of the major concerns in the present power system environment. The situations like, voltage dip/sag, swells, harmonic content, etc. and their major effects on greatly susceptible loads are well known. To tackle these situations, custom power equipment are utilized. In this work, Proportional Integral (PI) control technique based Dynamic Voltage Restorer (DVR) is implemented in power distribution system to suppress voltage sag and swell under linear and non-linear load conditions.In conventional method, DVR is proposed to mitigate the voltage sag. But, presence of voltage swell may cause variation in output. In the proposed system, DVR with PI control technique is implemented which compensates both sag and swell. Using the program MATLAB 2014a, the design of the Superconducting Magnetic Energy Storage (SMES) module as a dc voltage source for minimizing voltage sag and improving the power efficiency of a DVR-based distribution system was presented. The simulation results show that the SMES-based DVR easily compensates both sag and swell and provides excellent voltage control in balanced and unbalanced situations.

Performance Evaluation of Effective Controller for Buck-Boost DC-DC DSNIBBC

This paper deals about the development of intelligent controllers (ICs) for load voltage regulation of a double switch noninverting buck-boost DSNIBBC operated in pseudo continuous coil current (PCCC). The DSNIBBC is a kind of DC-DC converter, which converts the positive DC source voltage into the positive DC load voltage (buck to boost mode and boost to buck mode). Due to the time changing, ON/OFF characteristics along with its transient and dynamic characteristics of DSNIBBC have become nonlinear. Since the classical linear controllers are inappropriate to enhance the transient and dynamic performances of DSNIBBC, ICs are designed to improve the load control of the same DSNIBBC operated in transient and dynamic regions. In this paper, two ICs, namely, fuzzy logic controller (FLC) and neuro controller (NC) incorporated in the load voltage regulation loop are utilized. The performance comparison between the ICs and the classical proportional integral (PI) controller is discussed and validated at various regions through both software and prototype field programmable gate array [FPGA] plants. The responses are depicted to support the designed ICs.

Novel Reduced Switch Multi-Level Inverter for Range Extension of Novel EV Configuration

This project gives the novel idea of electric vehicle configuration for heavy vehicles which are most used in up and downstream. This configuration help to improve the efficiency of the system by twice when it is operated in the downstream. so, the concept is modifying the hybrid electric vehicle configuration by changing the internal combustion engine with a generator in addition to minimize the loss and increase the battery performance using a multilevel inverter. Multilevel Inverters are a new group of converters for DC-AC conversion in the medium and high voltage and power applications. In this paper, a new topology for the stepped wave output voltage generations have been proposed with a smaller number of switches. The topology needs 3 DC voltage sources and 7 switches to produce 15 levels at the load, beyond having a smaller number of switches has the advantages in terms of low voltage stresses across the switches. As an add on, a detailed comparative study of different topologies has been discussed in the paper to illustrate the advantages and features of the proposed topologies. Finally, experimental results have been included in the paper to validate the performances of the proposed topologies with a resistive load, and the prototype model is done for the multilevel inverter and the output displayed.

Three-phase five-level CHB inverter fed induction motor for renewable applications

<p><span lang="EN-US">This paper presents the three-phase CHB inverter fed induction motor suitable for renewable energy source applications. Normally, all present existing multilevel inverters produce multilevel output, but the number of components required is more, bulk in size, more in cost. Which are more burdens to small capacity renewable sources. These challenges are eliminated in CHB inverter. This CHB mainly consisting of one DC source, one capacitor and eight switches in each phase. To generate a five-level output in phase to ground voltage, it is required to maintain the capacitor voltage (V2) at fifty percent of the DC source voltage (V1). This capacitor voltage is regulated by a sensor less voltage regulating technique. The sensor less voltage regulation works without any sensor devices. We can implement this technique with very less cost compared to other techniques. The sensor less voltage regulation is realized by level-shifted sinusoidal pulse width modulation. The simulation results show a very good dynamic performance. Controller maintains the capacitor voltage at fifty percent of the source voltage irrespective of main source voltage changes and load changes. Inverter generates a five-level wave at the output from line to ground and seven-level wave from line to line with fewer Harmonic. It is implemented in matlab/simulink and showing good dynamic performance.</span></p>

Improving the DC-Link Utilization of Nine-Switch Boost Inverter Suitable for Six-Phase Induction Motor

Nowadays, multiphase induction drives are used in electric vehicle applications to improve reliability and efficiency. These induction motors are controlled by using a multiphase voltage-source inverter (VSI). As the number of phases increases, the number of switching devices used in multiphase VSI also increases, which results in a reduction of the system efficiency and an increase in the cost. Among these multiphase drives, the six-phase drive is used more frequently in electric vehicular industries. A conventional six-phase VSI requires 12 switches to drive the six-phase machine. Also, conventional six-phase VSI requires more dc-link voltage than the boost six-phase VSI to drive the six-phase machine. In order to overcome the problems associated with the conventional six-phase VSI-controlled six-phase induction drives, this article proposes a nine-switch boost inverter (NSBI) for six-phase induction drive applications. The proposed NSBI has a single-input dc voltage source, and it provides six-phase ac output voltages. These six-phase output voltages are regulated by using modified nonsinusoidal pulsewidth modulation (MNSPWM) technique. The proposed NSBI with a six-phase induction motor is simulated using MATLAB/Simulink and validated using a field-programmable gate array (FPGA)-controlled hardware prototype. The verification of the proposed system during load-torque variations and winding-failure conditions is carried out.

Component Count Reduced, Filter-Less H-Bridge Multilevel Inverter with Series and Parallel Connected Switches

This paper introduces a new premium multilevel inverter (MLI) topology with cascaded H-Bridge and series-parallel connected switches to synthesize the fundamental sine wave with various levels of voltage. The component count is decreased by reducing the number of power switching devices, optoisolators, voltage gate drivers, snubber and filter circuits. The combination of two power switches and a separated DC (SDC) source is called an SDC module. Five SDC modules are required for a 63-level MLI and six SDC modules are required for a 127-level MLI. In this paper, both a 63-level and a 127-level filter-less single-phase MLIs are deliberated. The switches are controlled by employing a newer pulse width modulation (PWM) technique called periodic reduced digital carrier level shift PWM (PRDCLSPWM). As the number of levels increases to a greater extent, the total harmonic distortion diminishes without the need of filter circuit and the performance level also increases. Comparative analysis of proposed 63-level and 127-level MLIs topology with the conventional and modern topologies has been presented in terms of power switches, gate driver circuit requirement, DC voltage sources and THD limits. PRDCLSPWM scheme is derived and analyzed for the proposed 63-level and 127-level MLIs to eliminate low-order and high-order harmonics. Moreover, the performance of the proposed modulation scheme is compared with the most commonly used schemes. The modeling and simulation are done with MATLAB/SIMULINK 2016a.

A Novel Boost Cascaded Multilevel Inverter

This article presents a novel cascaded multilevel inverter as an alternative to the cascaded H-bridge (CHB). By adopting two H-bridges integrated with two inductors and two power switches, the proposed topology is able to generate a five-level voltage with merely a single dc source. Voltage-boosting capability is guaranteed despite its single-stage operation. A corresponding modulation technique is also established to charge the boost inductors with a constant duty-cycle while simultaneously generating a five-level ac voltage. Therefore, the proposed topology outperforms the CHB in reducing the isolated dc source count, enhancing the voltage gain, and lowering the dc source voltage magnitude. In addition, the modularity is preserved, where the proposed topology can be extended by cascading multiple modules. The operation and feasibility of the proposed cascaded multilevel inverter is analyzed and validated through simulation and experimental results.