Conventional Voltage Source Inverter Research Articles

Analysis, design, and control of standalone PV based boost DC-AC converter

This paper presents a new control scheme for a boost DC–AC converter which is used for solar power applications. The proposed DC-AC converter configuration can produce an AC voltage level across the output or load side greater than input DC voltage based on the operating duty cycle. Generally, the conventional DC-AC converter or voltage source inverter (VSI) generates AC voltage which is less than input DC voltage. Maintaining a constant voltage across the load with improved dynamic performance is challenging for anyone for the solar photovoltaic (PV) system. A dual-loop sliding mode control is proposed for the boost VSI to address the above issues. The proposed controller has robust in nature against the wide fluctuation in the plant or load parameters. The design, analysis and control of the boost DC-AC converter are briefly discussed in this paper. This topology can be broadly used in solar powered uninterruptible power supply (UPS) where boosting operation is essential for low voltage solar PV system. This topology eliminates the DC boosting power processing stage which leads an improved efficiency of the overall system. The MATLAB/Simulink results are presented to highlight the above issues.

Review of Multilevel Level Inverter Using Different Topologies

This paper provides a concise overview of various multilevel inverter (mli) topologies. The conventional two-level voltage source inverter (vsi) necessitates a filter to generate sinusoidal output waveforms, which can be challenging at high frequencies due to switching losses. To address this issue, multilevel inverters offer lower switching frequencies and reduced total harmonic distortion (thd), eliminating the need for filters and large transformers. Moreover, a few advantages of mli inverters are reduced switching losses, better performance at high switching frequencies, and higher power quality (almost pure sinusoidal). Nevertheless, adding to the complexity of the system is the requirement for each switch to have its own gate driver in order to perform mli. Thus, it's imperative to decrease the mli's number of switches. In order to reduce the number of switches needed, this paper reviews some of the various current topologies. Applications such as voltage regulation, var compensation, harmonic filtering in power systems, and user interface for renewable energy have led to the development of cascaded h-bridge multilevel inverters. For solar applications, a modified cascaded h-bridge multilevel inverter (mli) is used. Cascaded h-bridge topology multilevel inverter will aid in reducing the number of switches. Comparing this concept to other multilevel inverters, the switching complexity is reduced.

Comparative Evaluation of Dual-Purpose Converters Suitable for Application in DC and AC Grids

This paper presents a comparative evaluation of several topological solutions to the universal power electronics interface for the dc or single-phase ac grids using the same terminals. The idea of a dual-purpose approach lies in the utilization of the same semiconductors in the dc-dc and in the dc-ac configuration, resulting in minimal redundancy. Particular focus is on the power density improvement and control. Out of the three solutions under investigation, the first is the buck-boost cell with unfolding circuit presented earlier. The second solution is a conventional voltage source inverter with an intermediate boost cell considered as one of obvious competitors. The third design is based on a phase-modular solution with buck-boost cells. The design example and experimental prototypes of the universal power electronics interface converter rated for 3.6 kVA power in the ac mode and more than 5 kW in the dc mode are presented. Our experimental results demonstrate the ability of operation in the ac or dc grids with main corresponding modes. Possible applications along with main benefits are addressed in the conclusions.

Design and analysis of electric spring based on battery-less current-source inverter

PurposeElectric spring (ES) is a demand response method that can stabilize the voltage of critical loads and improve power quality, especially in a weak power grid with a high proportion of renewable energy sources. Most of existing ESs are implemented by voltage-source inverter (VSI), which has some shortcomings. For example, the DC-link capacitor limits the service life of ES, and the battery is costly and hard to recycle. Besides, conventional VSI cannot boost the voltage, which limits the application of ES in high-voltage occasions. This study aims to propose a novel scheme of ES to solve the above problems.Design/methodology/approachIn this work, an ES topology based on current-source inverter (CSI) without a battery is presented, and a direct current control strategy is proposed. The operating principles, voltage regulation range and parameter design of the proposed ES are discussed in detail.FindingsThe proposed ES is applicable to various voltage levels, and the harmonics are effectively suppressed, which have been validated via the experimental results in both ideal and distorted grid conditions.Originality/valueAn ES topology based on battery-less CSI is proposed for the first time, which reduces the cost and prolongs the service time of ES. A novel control strategy is proposed to realize the functions of voltage regulation and harmonic suppression.

Performance evaluation of Renewable Energy Sources based grid connected system considering Unified Power Flow Controller

The quality of power is a major concern for the utilities and the power industries. Since the 1980’s, the term power quality has become a very prevalent one. There are various factors that affect the power quality, such as sag, swell, and power factor variation. The main cause of these issues is the use of non-linear loads. In a RES based grid-connected system, harmonics variation is one of the main issues that can affect the quality of power. Hence to address this in this paper Unified Power Flow Controller (UPFC) is proposed for the grid connected system. Many papers were proposed with the various FACTS devices but the performance of the proposed system exhibits a better one. In this paper application of UPFC is implemented in MATLAB/Simulink on test cases of wind-based grid connected system and PV based grid connected system. The performance of the proposed UPFC is compared with conventional Voltage Source Inverter (VSI). In all the cases the proposed UPFC exhibits the improved performance. This ensures the reduction in the harmonics in the power system in future.

Design and analysis of trans Z-source inverter for electric vehicle applications using neural network-clustering

The presented paper analyzes the detailed design of a trans Z-source inverter (ZSI) with an input from solar photovoltaic (SPV) system. Increase in SPV uses requires highly efficient SPV enabled inverters under varying weather parameters are in high demand in modern smart grid applications. The SPV-trans ZSI has high conversion efficiency because of the single-stage voltage boost conversion capability. In contradiction, the conventional voltage source inverter (VSI) requires an additional step-up transformer to boost the output voltage of inverter. This reduces the efficiency by increasing the volume of set up and also increase the cost of the system. In the proposed SPV system it provides a better output against VSI. The increase in inverter output voltage is because of shoot through time period present in ZSI. It also reduces the voltage stress and harmonics content as compared to VSI. The proposed model has been validated through MATLAB simulation.

Build a DC to AC Inverter Circuit with IOT Based Load Monitoring

Abstract: The boost inverter or boost DC-AC converter is a new voltage source inverter (VSI) that is suggested in this research. The novel inverter topology's key feature is that, depending on the instantaneous duty cycle, it produces an AC output voltage that is greater than the DC input voltage. This characteristic is not present in the conventional VSI, which consistently generates an AC output instantaneous voltage lower than the DC input voltage. A sliding mode controller is suggested to optimize the boost inverter dynamics while guaranteeing proper functioning under any working circumstance. The primary benefit of sliding mode control over traditional control strategies is its resistance to changes in plant parameters, which results in invariant dynamics and steady-state response in in the best scenario. This study covers operation, analysis, control technique, and experimental outcomes. When an AC voltage greater than the DC link voltage is required, the new inverter is designed to be employed in UPS and AC driver systems without the requirement for a second power conversion stage

PMSG Wind Energy Conversion Systems ZSI

Abstract: Recently Permanent Magnet Synchronous Generator are mostly used in the Wind Energy Conversion System applications This work is clearly deal with the study of Wind Energy Conversion System WECS by way of Permanent Magnet Synchronous Generator PMSG with Z Source Inverters. The PMSGs and wind turbines are gradually entered in the field of power generation huge wind farms are used at constant voltage and frequency to increase capacity power supply Particularly Permanent Magnet Synchronous Generators is used in this machinery due to special characteristics such as low weight volume and high. PMSG never required the power supply at the starting time of power production PMSGs run at synchronous speed. These type of inverter are classified has Z-Source Inverter ZSI, Quasi Z Source Inverter QZSI, Trans Z Source Trans ZSI and Cascaded Multi Cell Z Source Inverter CMCTZSI etc. This inverter is operated such as shoot through state and on shoot through state previously to convert DC supply to AC supply where the DC supply side have been boosted up to required AC supply level are executed. The above mention shoot through state is not applicable to implementing in the conventional Voltage Source Inverter VSI and Current Source Inverter CSI. The PMSG and types of Z Source inverter systems are simulated in MATLAB Simulation platform.

Theoretical and Experimental Comparative Analysis of Finite Control Set Model Predictive Control Strategies

This research paper studies and highlights the features of the most popular finite control set model predictive control (FCS-MPC) strategies available in the state of the art, which are the optimal switching vector (OSV-MPC), modulated model predictive control (M2PC), and optimal switching sequence (OSS-MPC) methods. Thus, these strategies are studied experimentally by analyzing the transient and steady state performance using a grid tie conventional three-phase two-level voltage source inverter (VSI) with inductive output filter in a Typhoon HIL real-time simulator (RTS) with a Texas Instruments F28379D digital signal processor (DSP). Hence, quantitative indicators, such as the maximum tracking error, the mean absolute error, the settling time, the total harmonic distortion, the switching frequency spectrum, the switching pattern, and the computational burden are compared with the aim to deduce the best strategy for each criteria.

Field Programmable Gate Array-Based Execution on a Distributed Energy Resource Supported Electrical Distribution System for Enhanced Power Quality with Optimal Active Power Flow Control

This paper explains the experimental study of a distributed energy resource (DER) integrated three-phase, three-wire electrical distribution system (EDS) under power quality (PQ) and optimal active power flow control (OAPFC). In this research, a back-to-back connected two-level VSI (BTB-TVSI) based distribution static compensator (DSTATCOM) for unbalanced non-linear load is designed. The aim is to provide better OAPFC in EDS with shunt compensation to maintain a round-the-clock quality power supply for end users. The improved neural network-based adaptive least mean square (ALMS) control algorithms are employed for DSTATCOM. The ALMS control strategy is realized using the SPARTAN-6 field programmable gate array (FPGA) evaluation kit. This research involves the comparative study of a two-level voltage source inverter (VSI) and a BTB-TVSI in terms of their OAPFC capability and robustness in mitigating power quality (PQ) against source current disturbances, low power factor (PF), poor voltage regulation, unbalanced voltage at the point of common coupling (PCC), high switching stress, and issues in the EDS operation. The experimental results demonstrate that the BTB-TVSI using an ALMS controller is able to achieve better dynamic performance and lower total harmonic distortion (THD) under selected/permissible limits in comparison to a conventional VSI.

Comprehensive Analysis and Evaluation of DC-Link Voltage and Current Ripples in Symmetric and Asymmetric Two-Level Six-Phase Voltage Source Inverters

Multiphase drives (MPD) in general and six-phase in particular have been gaining popularity in many industries, which calls for a proper multiphase inverter (MPI) design. For voltage source inverter (VSI)-fed drives, the knowledge of voltage and current stresses on the dc-link are imperative for input capacitor sizing. To this end, the voltage and current stresses on the dc-link capacitor in two-level six-phase VSIs are examined thoroughly in this article for two configurations of load/winding spatial distribution: symmetric and asymmetric. First, the harmonic spectrum of the input dc current of each inverter is analyzed in detail by benchmarking them against the conventional three-phase VSI, to precisely establish the dc-capacitor requirement reduction in six-phase counterparts. Second, analytical formulae for the dc-link capacitor voltage ripples are derived for both configurations. Third, simple formulae for dc-capacitor sizing for six-phase VSIs with different load configurations are provided. The accuracy of the derived formulae is verified by simulation and experimental testing at various power factors and modulation depth. It is found that six-phase VSI supplying symmetric and asymmetric loads reaps 10% and 7% lower dc-link current ripples, respectively. Hence, six-phase symmetric loads yield the smallest capacitor size.

An Efficient Modified Z Source Grid Tied Inverter System

In this paper presents the controlling the power of using quasi-Z source inverter for renewable source application. The proposed quasi z source is single stage DC to AC converter it delivered buck-boost operation with respect to input. These buck-boost converter is highly suitable compare to the normal dc to dc converter for photovoltaic applications. The proposed single stage converter are reliable and suitable for renewable energy source application. The source impedance quasi network offers high gain compare to the exciting system and reduced the total harmonic level. The quasi-z source followed by single phase H bridge converter uses to convert DC to AC with high reliability output. A proposed system-built Simulink and the hardware made for the open loop control. The conventional voltage and current source inverter have its own limitation of the output voltage low compare to the input source in the voltage source inverter, it is just opposite in the current source inverter. These limitations overcome by designed novel modified z source inverter was developed and controlled pulse using unipolar and bipolar concept. The output of the inverter after filter, it produces the less harmonics result 7.6% on fifth harmonics level compare with conventional inverter.

An Improved Hybrid Parallel Compensator for Enhancing PV Power Transfer Capability

This article proposes an improved hybrid parallel compensator (IHPC) for enhancing the power transfer capability of a photovoltaic (PV) grid-connected inverter. A thyristor switched capacitor (TSC) module is used in series with a conventional inductive-coupling voltage source inverter to reduce the dc-link voltage. Under a low dc-link voltage, the voltage across the insulated gate bipolar transistor (IGBT) will also be low, which will reduce the voltage stress of the IGBT, thereby improving the reliability and reducing the loss of the voltage resource inverter. First, the mechanism of reactive compensation for improving the PV inverter power transmission capability is analyzed. Then, the circuit configuration and operating principle of the IHPC are introduced. After that, an optimal control strategy for the IHPC is proposed to address the resonance problem caused by the TSC connected in series with the L filter and to improve the compensation performance of the IHPC. Finally, the effectiveness of the proposed IHPC and the control method is validated by the simulation and experiments. The results show that the IHPC with optimal control strategy can achieve continuous reactive power compensation under a low dc-link voltage, thereby enhance PV power transfer capability.

A Simple Method for Stator Inductance and Resistance Estimation for PMSM at Standstill

An accurate stator resistance and inductance are necessary for high-performance permanent magnet synchronous motor (PMSM) control. The stator resistance and inductance can be estimated during motor standstill operation. This study proposes a standstill estimation method for the determination of dq-axis inductances and resistance of a PMSM drive system fed by a conventional voltage source inverter (VSI). The proposed method estimates both inductance and the rotor's position using the same algorithm, and knowledge of its initial position is not required. The d- and q-axis inductances were estimated by applying three short-time voltage pulses and measuring phase current peak values. The stator's resistance is estimated by monitoring the exponential decay process of the direct axis current. The method was verified by simulation and experiments conducted on two different PM synchronous motors. A good agreement of simulation and experimental results was obtained. Moreover, the proposed method is relatively simple and can identify stator resistance and inductance at any motor load condition. Compared to the existing parameter estimation strategies, the proposed estimation scheme has a relatively faster estimation time. Additionally, it is shown that the method accounts for the dead-time effect as well.

An DPWM for Active DC-Link Type Quasi-Z-Source Inverter to Reduce Component Voltage Rating

The conventional DC-link type quasi-Z-source inverter has been known as a buck–boost inverter with a low component voltage rating. This paper proposes an active DC-link type quasi-Z-source inverter by adding one active switch and one diode to the impedance-source network to enhance the voltage gain of the inverter. As a result, the component voltage rating of the inverter is significantly reduced, which is demonstrated through some comparisons between the proposed topology and others. A discontinuous pulse width modulation (DPWM) scheme is proposed to control the inverter, which reduces the number of commutations compared to the traditional strategy. Under this approach, the insertion of a shoot-through state does not cause any extra commutations compared to the conventional voltage-source inverter. Details about control implementation, steady-state analysis, and design guidelines are also presented in this paper. Simulation and a laboratory prototype have been built to test the proposed inverter. Both buck and boost operations of the proposed inverter are implemented to validate the performance of the inverter.

Mitigation of Circulating Bearing Current in Induction Motor Drive Using Modified ANN Based MRAS for Traction Application

Induction motors are popularly used in various applications because of the proposed modest construction, substantiated process, and limited size of specific power. The traditional AC traction drives are experimentally analyzed. There is a high circulating current due to the high Common-Mode Voltage (CMV). The high Circulating Bearing Current (CBC) is a major problem in conventional two-level voltage source inverter fed parallel-connected sensor-based induction motors for traction applications. A sensorless method is well known for shrinking costs and enhancing the reliability of an induction motor drive. The modified artificial neural network-based model reference adaptive system is designed to realize speed estimation methods for the sensorless drive. Four dissimilar multilevel inverter network topologies are being implemented to reduce CBC in the proposed sensorless traction motor drives. The multilevel inverter types are T-bridge, Neutral Point Clamped Inverter (NPC), cascaded H-bridge, and modified reduced switch topologies. The four methods are compared, and the best method has been identified in terms of 80% less CMV compared to the conventional one. The modified cascaded H-bridge inverter reduces the CBC of the proposed artificial neural network-based parallel connected induction motor; it is 50% compared to the conventional method. The CBC of the modified method is analyzed and associated with the traditional method. Finally, the parallel-connected induction motor traction drive hardware is implemented, and the performance is analyzed.

A Topological Advancement Review of Magnetically Coupled Impedance Source Network Configurations

Magnetically coupled impedance source networks provide a wide range of applications, such as dc to dc, dc to ac, ac to ac, ac to dc unidirectional or bi-directional power conversion. Various impedance source networks are reported in the literature to overcome the barriers of conventional voltage source inverters. They offer high boost with buck-boost capabilities and reduce power conversion stages. Thus, they provide an economical solution to expanding power systems, and are most suitable for renewable sources having low output. The goal of this study is to provide an in-depth comprehensive review of the major topologies of magnetically coupled impedance source networks. The review is more focused towards the fast-growing niche area, which has seen many advancements in the last few years. Best efforts are made to include relevant major topological advancements, with the aim of providing relevant and accessible information for researchers. This research provides a detailed comparison of essential factors and presents a full assessment of major topological improvements in MCIS networks.

Transformer-Less Cascaded Voltage Source Converter Based STATCOM

In this work, a transformer-less voltage source converter (VSC) based STATCOM is proposed with a combination of cascaded conventional three-phase voltage source inverters. This modular structure provides multilevel operation with reduced switch count and independent DC-link capacitors. The actual contribution of this paper is the transformer-less configuration of a conventional cascaded voltage source converter which provides reduced cost and volume as compared to other transformer-less converter configurations. The system provides reactive power compensation with better power quality when connected to the nonlinear power electronics load also. A simple control system is provided for balancing the Dc link capacitor voltage and reactive power compensation. The validation of the proposed model is analyzed with simulation using MATLAB/SIMULINK software and the results are obtained with different linear and nonlinear load configurations.

Bidirectional Quadratic Converter-Based PMBLDC Motor Drive for LEV Application

In this study, a bidirectional DC-to-DC quadratic converter (BDQC) is designed and developed for the motoring and regenerative braking (RB) of a permanent magnet brushless DC (PMBLDC) motor for a light electric vehicle (LEV) application. A PMBLDC motor is deemed more suitable for an electric vehicle (EV) due to its high efficiency and torque density. In the present work, a BDQC of 1 kW is designed to drive a 1.1 HP PMBLDC motor through a conventional voltage source inverter (VSI). An EV’s load cycle is emulated using a highly inertial load driven by a PMBLDC motor during the converter’s boost mode operation. RB is a crucial factor in extending the driving range of EVs by efficiently utilizing battery power. The converter operates in buck mode during RB, and simultaneously, the back electromotive force (EMF) of the PMBLDC machine is boosted by the self-inductance of the PMBLDC motor and the VSI. The braking technique used in this work eliminates the traditional drawback of RB in buck mode, as the power is extracted even when the motor’s back EMF is lower than the battery’s voltage. The control strategy has been implemented using the TMS320F28335 DSP controller for a developed converter prototype of the converter and driving the PMBLDC motor. The experimental results are compared to the simulation results, and a good alignment has been found.

Tapped inductor based switched boost inverter: Analysis and implementation

AbstractIn a Z‐source inverter, an inductor‐capacitor (LC) impedance network is used between the inverter bridge and the power source. These inverters can be used in boost and buck modes. Other advantages of this structure include resistance to electromagnetic interference (EMI) disturbances compared with conventional voltage source inverter (VSI). However, the LC impedance network significantly increases the size and cost of the power converter. Therefore, these converters are not suitable for low power applications. In this paper, a switched Z‐source inverter with the capability of high voltage gain by using coupling inductors is proposed. One of the main features of this structure is improving the boost factor and improving the inverter voltage gain without changing the duty cycle. A complete analysis of the inverter performance and a comprehensive comparison of its features concerning different structures are provided. Finally, in order to confirm the accuracy of the inverter operation, its laboratory results are presented.