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To improve the dynamic response of the inverter, the conventional proportional–integral controller and the modulation part are substituted by the finite-control step model predictive control (FCS-MPC) strategy. Compared to the two-level inverter, the drifted neutral point potential is an issue that cannot be neglected. To resolve this issue, the cost function is modified in this paper. Besides, as all of the voltage vectors are employed during optimal research progress in FCS-MPC, the switching frequency is variable, which burdens the filter. The complex calculation progress also burdens the microcontroller. According to the conventional modulation algorithm, the voltage vectors are divided into several groups and the optimal calculations are simplified with them. Based on that modification, the switching frequency is fixed. Finally, the simulation and the experimental results are demonstrated, which reveal the validity and merits of the proposed method. [ABSTRACT FROM AUTHOR]

A low-power grid-connected photovoltaic (PV) power generation system based on automatic solar tracking is designed in this paper. In order to increase the level of accuracy of automatic solar tracking, the part of automatic solar tracking adopts the method of hybrid tracking and uses pin-cushion two-dimensional position sensitive detector plus four silicon PV cells as the photosensitive element. An adaptive topological structure of the main circuit based on a cascaded Boost converter circuit and the H6-type inverter topology are designed for the system to obtain a better working condition. Then an MPPT algorithm combined modified constant voltage algorithm with modified variable step-size increment conductance algorithm is proposed in order to improve the efficiency of PV power generation. The experimental results showed the effectiveness of the control system. Finally, the hardware and software of the system are also designed. Moreover, a graphic interface made with the LabVIEW software allows the user to monitor and save the data in a file. [ABSTRACT FROM AUTHOR]

The introduction of Variable Speed Drives (VSD) motor driven systems in industry is driven by the desire to increase motor efficiencies in plant. The efficiency savings are usually determined by initial energy assessments which consider factors such as the motor load type and operating conditions where the motor actual load may also be measured. However, once the system is installed and in operation, the designed-in energy efficiency of these systems may remain unchecked throughout the lifetime of the installation. Efficiency reductions may be caused by mechanical or electrical degradation of equipment that could remain undetected by the drive or user whilst the equipment appears to operate as normal. On larger systems, the financial cost of reduced efficiency can be significant. The aim of this paper is to simulate minor deteriorations in the operating conditions of a standard motor controlled from a VSD and ascertain if the worsening condition can be detected at an early stage. The deterioration in motor condition will be small enough to remain undetected by the VSD and not cause a drive fault. This paper also reviews the effect of the introduced motor imbalance on motor efficiency and introduces power factor measurement methods which can be a useful indicator of increased operating costs for equipment. Test results from the two drive operating modes of Volts/Hertz (v/f) and Sensorless Vector (SV) are compared. This is to determine if there is any noticeable difference in the measurements obtained for efficiency and power factor between drive operating modes. [ABSTRACT FROM AUTHOR]

Many wind turbine generations have been installed into power systems around the world, where in recent years doubly fed induction generator (DFIG) attracts a lot of attentions because of its efficiency and controllability. However, the DFIG is connected to the power system through inverters and originally does not have an ability to release the kinetic energy of the rotor or resorb the surplus power of the power system as the kinetic energy. Therefore, it has not been made clear how the DFIGs have an influence on small-signal stability in power systems. In this paper, we propose a control scheme of the DFIG and analyse its effect on the small-signal stability of the power system by eigenvalue calculations and time-domain simulations. [ABSTRACT FROM AUTHOR]

The erosion of the stress grading system of converter-fed rotating machines may occur by partial discharges and heat generation. There remain unclear issues in the formation of the potential and temperature distributions along the stress grading system of coils. In this paper, the potential distributions on the stress grading system of the model coil bar are measured under the application of 1 kHz square wave voltages of 10 kV in peak to peak value with/without 5 kV DC biased voltage. It turns out that DC bias voltage has little effect on potential distribution on a coil surface. [ABSTRACT FROM AUTHOR]

Modified switching patterns for Z-source inverters (ZSIs) from the traditional inverter schemes have reached the point where further improvements in fi ring the switches and inserting the shoot-through (simultaneous conduction of same phase leg switches) periods bring crucial benefits. A large variety of control methods, different in concept and performance, have been developed and described. This paper analyses the implementation logics, and comparative merits and demerits of recently-developed carrier-based and space-vector-based modulation techniques of ZSIs. Carrier-based pulse-width modulation (PWM) schemes, such as maximum boost control with third harmonic injection and constant boost control with third harmonic injection, and space vector modulation-based PWM schemes for three-phase ZSIs are investigated. The suitability of these techniques for various applications is also outlined. The objective of this paper is to provide a comprehensive assessment of the above PWM schemes, thereby giving a framework and guidance for the selection of the best technique for each area of application. The analysis is performed with respect to switching stress, boosting capability, voltage gain, total harmonic distortion, ripples in impedance network elements and the range of controllability. All the above control methods are simulated by Matlab/Simulink software and verified by experiments. [ABSTRACT FROM AUTHOR]

In traditional control strategies, with three state transitions three equal interval shoot-through states can be added immediately adjacent to the active states per switching cycle for modulation of three-phase three-wire three-two leg Z-source inverters. The Z-source capacitor voltage is controlled by the shoot-through duty ratio and the output voltage is controlled by the modulation index, respectively. Modified space vector modulated (MSVM) control provides better AC output control with effective DC boost, but still it has two-stage controllers. The algorithm presented in this paper provides a modified voltage space vector with single-stage control having one degree of freedom with improved AC output voltage control and reduced harmonic profile. The simulation has been performed in Matlab/Simulink and the relative simulation results with traditional control method have been presented to validate the proposed algorithm. The integrated control algorithm using modified voltage space vector is presented in this paper and experimentally verified with Z-source inverter prototype in the laboratory. [ABSTRACT FROM AUTHOR]

This paper deals with the topological analysis of a novel improved three-level Z-source inverter. By connecting a Z-source network to the rear end of the existing three-level inverter, it produces boosted voltage output with reduced Z-source capacitor voltage and limited inductor inrush current. Simulations are carried out using simple boost switching scheme in Matlab/Simulink environment. Laboratory prototype is made to illustrate its performance. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the circulating current produced as a result of a difference between the dead-times of two voltage source inverters with space vector pulse-width modulation, connected in parallel without galvanic isolation to a load. An algorithm has been identified that calculates the difference between the dead-times through the difference of the homologous output voltages of the inverters. The article proposes a correction of the dead-time imbalance, through proportional-integral control, in order to reduce the circulating current and increase the system's performance. [ABSTRACT FROM AUTHOR]

The application of insulated gate bipolar transistors (IGBTs) in power inverters/ converters has witnessed a significant increase in the last two decades; requiring very comprehensive and fool-proof protection. This paper critically examines and compares some of the published short-circuit protection circuits for IGBT inverters and suggests a newly designed and developed short-circuit and current limit protection. The experimental results as conducted in the laboratory show that the proposed protection system helps the inverter to deliver fail-safe operation. [ABSTRACT FROM AUTHOR]

Digital simulation and implementation of a power factor correction (PFC) zeta converter based adjustable speed controlled voltage source inverter (VSI) fed permanent magnet brushless DC (PMBLDC) motor for mining application is presented in this paper using low cost embedded controller. The main attractive feature of the zeta converter is that it has a naturally isolated structure, which allows a regulated output voltage with only one power processing stage. The VSI is used as an electronic commutator for the motor. This drive ensures high power factor at the input side. The speed control scheme has the concept of DC-link voltage control proportional to the desired speed of the PMBLDC motor. The speed is regulated by a proportional-integral controller. The proposed PFC zeta converter based PMBLDC motor drive is designed, modelled and simulated using MATLAB/Simulink environment. The results of PFC zeta converter system are compared with the results of VSI-fed PMBLDC drive with L-filter and T-filter at the input side. The power factor is found to have improved using zeta converter. The hardware is implemented using reduced cost embedded controller with zeta converter as PFC converter. Merits of the proposed power converter include improved power factor, less harmonic content and simplified control strategy. The experimental results are compared with the simulation results. [ABSTRACT FROM AUTHOR]

The paper proposes a novel balancing algorithm of neutral-point (NP) potential for the three-level NP-clamped inverters, which is based on appropriate zero-sequence voltage injection. The relationship between the NP average current and zero-sequence voltage injected is studied comprehensively. The NP average current injection allowance for controlling NP potential are derived. The theoretical optimum zero-sequence voltage for controlling NP potential is obtained by the relationship. Simulation and experimental results verify validity and practicability of the algorithm. [ABSTRACT FROM AUTHOR]

In traditional Z-source inverter (ZSI) fed induction motor drives, the Z-source capacitor voltage and the motor terminal voltage are controlled by the shoot-through duty ratio and the modulation index, respectively. Modified voltage space vector has been proposed to improve motor terminal voltage control with effective DC boost in the DC link. For the same shootthrough duty ratio, modified voltage space vector provides better voltage boost in the DC link with reduced harmonics in the load side than the traditional voltage space vector. This paper presents an integrated control technique to minimise the electromagnetic torque ripples in the rotor of the ZSI-fed induction motor drives using modified voltage space vector. To improve the stability of the overall drive system, the motor terminal voltage alone is sensed instead of sensing the Z-source capacitor voltage and motor terminal voltage independently. This provides a single-stage controller for motor drive systems. The proposed induction motor drive system provides a better ride-through capability during voltage sags, better line harmonic profile, and minimisation of the torque ripples in the rotor. The proposed control technique is simulated using MATLAB/Simulink software, and analysis and experimental results have been presented to validate them. [ABSTRACT FROM AUTHOR]

This paper presents the hybrid phase-shifted carrier (PSC) modulation for cascaded voltage source inverters, investigates their performance characteristics, and provides a comparison with the standard pulse-width modulation (PWM) methods. The proposed PWM combines the features of fundamental frequency PWM and high-frequency PSC-PWM in power conversion, and resolves the contradiction between high frequency and accuracy in a digital control scheme. The proposed PWM is developed based on PWM base generator and hybrid PWM control algorithm, and it is implemented using TMS320 F2407 DSP processor and Xilinx XC95108 CPLD controller, respectively. The main characteristic of this hybrid modulation is the reduction in switching losses, effectively improving harmonic performance, and solving the problem of unequal voltage stress and current stress of power devices. The performance of this hybrid modulation is analysed and compared with the original strategies. Power losses, total harmonic distortion (THD), weighted THD and the normalised weighted THD are evaluated. Simulation and experimental results verify that the proposed PWM technique is superior to standard techniques. Finally, it is concluded that the proposed strategy is highly suited to inverters with high number of voltage levels. [ABSTRACT FROM AUTHOR]

In traditional Z-source inverter (ZSI) fed induction motor drives, the Z-source capacitor voltage and the motor terminal voltage are controlled by the shoot-through duty ratio and the modulation index, respectively. Modified voltage space vector has been proposed to improve motor terminal voltage control with effective DC boost in the DC link. For the same shootthrough duty ratio, modified voltage space vector provides better voltage boost in the DC link with reduced harmonics in the load side than the traditional voltage space vector. This paper presents an integrated control technique to minimise the electromagnetic torque ripples in the rotor of the ZSI-fed induction motor drives using modified voltage space vector. To improve the stability of the overall drive system, the motor terminal voltage alone is sensed instead of sensing the Z-source capacitor voltage and motor terminal voltage independently. This provides a single-stage controller for motor drive systems. The proposed induction motor drive system provides a better ride-through capability during voltage sags, better line harmonic profile, and minimisation of the torque ripples in the rotor. The proposed control technique is simulated using MATLAB/Simulink software, and analysis and experimental results have been presented to validate them. [ABSTRACT FROM AUTHOR]

This paper presents the sliding mode control of a three-phase parallel active filter based on a two-level voltage converter to compensate for the harmonic currents of the pollutant loads. In order to calculate the reference harmonic currents, the p-q algorithm is used and the PWM is used to generate the control pulses of the inverter. Simulations in the Matlab-Simulink environment are provided to validate the theoretical study. The results obtained seem satisfactory in the harmonic compensation quality and the correction of the power factor. The selected comparison criteria are the transient regime and the Harmonic Distortion Rate in the line current. [ABSTRACT FROM AUTHOR]

In this paper a composite power control design comprising of both voltage oriented control and direct power control (DPC) is developed for the grid-combined scheme based on photovoltaic array excited wind driven induction generator with unbalanced non-linear load (UNL) at the point of common coupling (PCC). The control and design strategy of the developed controller aims at control of instantaneous active and reactive power exchanged with the grid and suppression of the power oscillating terms that appear due to interaction between the different voltage and current sequences. When an induction generator feeds a non-linear load, de-rating of machine occurs and an attempt is made to reduce induction machine de-rating factor due to UNL with proposed control. Exhaustive simulations have been carried out with UNL at the PCC with varying wind speed and irradiation in grid-connected mode. The results are compared with existing DPC scheme. The proposed controller is also tested in islanding mode with line to line fault and load rejection at the PCC. The feasibility of incorporating the new developed control algorithm for grid-connected hybrid scheme is indicated in this work. [ABSTRACT FROM AUTHOR]

There is a strong trend in photovoltaic (PV) inverter technology to use transformer less topologies in order to acquire higher efficiencies. This paper presents a single-phase seven-level grid connected PV inverter with two reference signals that are identical to each other with an offset that is equivalent in amplitude as of the triangular carrier signal. The triangular carrier signal is used to generate pulse-width modulation signals for the switches. Multi-string inverter based system gives better voltage regulation and efficiency compared to multi-level inverters. Seven-level multi-string inverter consists of two auxiliary switches and diodes. The inverter produces output voltage in seven levels. The validity of the proposed inverter is verified through simulation. The proposed multi-string inverter topology is further validated with analysis of maximum power point tracking using peripheral interface controller. [ABSTRACT FROM AUTHOR]

The article presents abstracts related to electrical and electronics engineering which include "Mal-tripping of a 132 kV busbar due to DC control cabling earth impedances," by N. Yu, "Web services for fault analysis in smart grid applications," by M. Musaruddin and R. Zivanovic, and "Analysis of advanced pulse-width modulation schemes for Z-source inverters," by S. Thangaprakash and colleagues.

A modified multilevel inverter with a configurable level generation is proposed in this paper. The MLI is composed of a modified boost converter at the front end followed by a level generation circuit and a H-bridge configuration. The front-end converter is biased with a PV source with a Hybrid boost resonant converter. The switches are triggered out of phase through a MPP tracker which uses Fractional INC MPPT. The secondary side of the circuit is composed of a derived voltage doubler along with the voltage regulator. The output of the doubler is regulated through a level converter which integrates a fuzzy controller and a phase shift controller. The modified multilevel inverter uses a low-voltage PV source as input and generates a variable-step multilevel output voltage with lower harmonic distortion and it is suitable for low-power PV applications. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid islanding detection method for inverter-based distributed generation (DG) based on frequency drift. This algorithm is a combination of Sandia frequency-shift, reactive power versus frequency and reactive power deviation as active methods, and over/under frequency protection as a passive method. The performance of the proposed method is evaluated under the UL 1741 anti-islanding tests configuration, IEEE 1547, load switching, load quality factor and multiple-DG operation. The simulation results are derived by MATLAB/ Simulink. Based on simulation results, it is clear that the proposed method is developed to detect islanding more efficiently for loads with high quality factor. The proposed method also has less non-detection zone comparing other methods. In addition, the proposed method operates accurately in condition of load switching while does not interfere with the power system operation during normal conditions. This technique proves to be robust under multiple-DG operation. [ABSTRACT FROM AUTHOR]

Focusing on the relative location of the centre of gravity of the pulse-width modulation waveform in each section, a novel direct digital sine pulse-width modulation (SPWM) method based on equal-area theorem for multilevel inverters is proposed in this paper. Three different direct digital SPWM schemes are illustrated and investigated thoroughly in terms of total harmonic distortion (THD) and amplitude of the fundamental-frequency voltage, and the best scheme with the lowest THD is identified. The THD and fundamental voltage produced with the proposed method with modulation index M varying from zero to its maximum value are calculated and compared with level-shifted carrier-based SPWM method. It is demonstrated that the proposed direct digital SPWM method can provide far lower THD, while its fundamental voltages are on par with the carrier-based SPWM method. Other advantages of the proposed modulation scheme include simplicity, digital oriented and generalised for multilevel inverter with any levels and any topologies, including cascaded H-bridge, neutral point clamped, flying-capacitor and any other types of inverters. Simulations and experiments are carried out. The experimental results agree well with simulations, which prove the validity of the proposed digital SPWM method. [ABSTRACT FROM AUTHOR]

This paper presents an isolated cycloconverter-type high-frequency (HF) link inverter that consists of three arms of bidirectional switches at the transformer secondary. This topology has the advantages of light weight and reduced switch count, when compared to other types of HF link inverters. However, like all HF link inverter topologies, this topology suffers from a high-voltage surge problem and power device switching loss. In order to overcome these problems, the natural commutation method that enables soft-switching operation is applied. To verify the viability of the scheme, a low-power laboratory prototype based on the Siemens 80C167 fixed-point microcontroller is constructed. In addition, the simulation of the inverter is also carried out. The prototype inverter is able to supply output voltage at 120 Vrms, with a total harmonics distortion of less than 1%. The total power conversion efficiency reaches 86% when the output power is over 300 W. [ABSTRACT FROM AUTHOR]

This paper presents an isolated cycloconverter-type high-frequency (HF) link inverter that consists of three arms of bidirectional switches at the transformer secondary. This topology has the advantages of light weight and reduced switch count, when compared to other types of HF link inverters. However, like all HF link inverter topologies, this topology suffers from a high-voltage surge problem and power device switching loss. In order to overcome these problems, the natural commutation method that enables soft-switching operation is applied. To verify the viability of the scheme, a low-power laboratory prototype based on the Siemens 80C167 fixed-point microcontroller is constructed. In addition, the simulation of the inverter is also carried out. The prototype inverter is able to supply output voltage at 120 Vrms, with a total harmonics distortion of less than 1%. The total power conversion efficiency reaches 86% when the output power is over 300 W. [ABSTRACT FROM AUTHOR]

For the brushless doubly-fed machine (BDFM), traditional direct torque control (DTC) has many problems such as big output torque ripple and uncertain inverter switch frequency. Based on the analysis of traditional DTC, this paper proposed a new torque control which applied duty ratio modulation into direct torque control. This new control method can decrease the torque ripple effectively by adding zero voltage in each control cycle. According to the brushless BDFM state equation and the prediction of torque, flux linkage in the next moment and the theory of electromagnetic torque equals to referenced value at the instant moment in one control cycle, torque ripple can be decreased. Through theoretical analysis and experiments, the proposed control method has all advantages of traditional direct torque control and can decrease torque ripple and flux linkage ripple, which can optimize the performance of direct torque control. [ABSTRACT FROM AUTHOR]

In this paper, a comparison of different optimisation algorithms on various digital circuits is investigated. We consider evolutionary algorithms such as ant colony optimisation (ACO) and quantum ACO (QACO) for optimisation of four different digital circuits, namely, transmission gate implementation of XOR gate, CMOS NAND gate, four-inverter CMOS buffer chain and a 1-bit full adder circuit. The transistor sizes of these circuits were optimised so as to obtain the minimum weighted average of power and delay. The simulation results show that the performance of QACO is better than that of the ACO for the circuitry containing more number of transistors. [ABSTRACT FROM AUTHOR]

Many traditional grids have started to integrate the DC/AC inverters in their networks. This requires a good control to enhance the power quality. The grid frequency behaviour is one of the principal indicators that reveal the power quality. Therefore, it must be strongly controlled. Up to now, the most popular frequency synchronization method is based on phase-locked loop (PLL) control. It is known that setting a current proportional to voltage does not work well and it creates a negative resistor in a wide frequency range because the circuit is not passive. This paper presents an alternative idea of synchronization of a single-phase grid-connected DC/AC inverter by using a double integration method. It is simpler than PLL since it needs neither a phase comparator, nor a local oscillator. It provides a signal in phase with the current. The art of the method is how to remove the integrating constants without degrading the signal. [ABSTRACT FROM AUTHOR]

To effectively utilize a photovoltaic (PV) system, reactive-power control methods for solar inverters have been considered. Among the various methods, the constant-voltage control outputs less reactive power compared with the other methods. We have developed a constant-voltage control to reduce the reactive-power output. However, the developed constant-voltage control still outputs unnecessary reactive power because the control parameter is constant in every waveform of the PV output. To reduce the reactive-power output, we propose a dynamic reactive-power control method with a PV output prediction. In the proposed method, the control parameter is varied according to the properties of the predicted PV waveform. In this study, we performed numerical simulations using a distribution system model, and we confirmed that the proposed method reduces the reactive-power output within the voltage constraint. [ABSTRACT FROM AUTHOR]

The article presents abstracts related to electrical engineering which include improving shunt hybrid filter performance through reducing control system time delay, time synchronization error correction for BiSAR and performance analysis of cascaded multilevel inverter.

Copyright of Automatika: Journal for Control, Measurement, Electronics, Computing & Communications is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automatika: Journal for Control, Measurement, Electronics, Computing & Communications is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper different electrostatic interdigitated comb designs for the new concept of MEMS based DC-AC capacitive power inverter for the solar photovoltaic applications has been compared and tested on the basis of different structures and materials used as a frame for the proposed model. To obtain better the performance and power conversion efficiency of the interdigitated comb drive capacitive DC/AC inverter at very low input voltage some structural parameters of the proposed model has been varied such as increase the number of comb fingers; reduced the gap between the fingers of the interdigitated comb with increase in thickness of the fingers and made uniformly tapered at its edges. As a structural material for the proposed model the polysilicon and indium antimonite has been employed, simulated, compared and tested and in COMSOL Metaphysics 5.0 environment with different comb structure to get better performances for solar photo voltaic application. The proposed MEMS DC/AC power inverter model can easily compete with the commercially available semiconductor inverters once it is implemented with efficient fabrication technology due to its certain merits over semiconductor power inverter in terms of miniaturized size, pure sinusoidal output voltage and current, regulated output frequency, ultra low power consumption, very low cost and off course very small or minimal power loss. [ABSTRACT FROM AUTHOR]

Copyright of Automatika: Journal for Control, Measurement, Electronics, Computing & Communications is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automatika: Journal for Control, Measurement, Electronics, Computing & Communications is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automatika: Journal for Control, Measurement, Electronics, Computing & Communications is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The performance of a pulse-width modulation (PWM) technique for soft switched cascaded five-level inverters are emphasised. The hybrid PWM topologies have been on spot light in industrial drives, the cascaded multilevel inverter can be asserted due to high power medium voltage applications. The proposed modulation schemes are hybrid alternative phase opposition disposition, hybrid phase shift carrier, hybrid single carrier sinusoidal PWM (SPWM) schemes. It inherits the switching loss reduction along with reduced harmonic performance of cascaded multilevel inverter fed drive system. The effectiveness of the novel concepts are validated experimentally. Simulation study of the inverter employing the proposed hybrid alternative phase opposition disposition and hybrid single carrier SPWM strategies has been done in MATLAB/Simulink. Among the existing design the efficient strategy is employed in the hardware implementation of hybrid multilevel inverter [ABSTRACT FROM AUTHOR]

The work focuses on the design and implementation of a field programmable gate array (FPGA) based voltage controller for a single-phase voltage source inverter (VSI) with an inductance-capacitance (L-C) filter. The control algorithm of the open loop and closed loop control schemes of the controller are designed using hardware descriptive languages (VHDL and VerilogHDL) and are implemented using Xilinx SPARTAN 3E FPGA. The sinusoidal pulse-width modulation (SPWM) technique is utilised to realise the controller with a provision to change the modulation index in response with varying load conditions. Suitable L-C filter is designed to minimise the undesirable frequency components in the output voltage. The efficacy of the proposed control schemes in FPGA is validated via successful interface with a prototype VSI and the experimental verification of the controllers are carried out under different loading conditions. [ABSTRACT FROM AUTHOR]

In this study, a new configuration for cascaded voltage source multilevel inverter based on series connection of improved sub multilevel inverter module is presented. An algorithm is proposed to determine the magnitude of dc voltage source to generate a large number of output voltage levels with reduced device count. It is especially suitable for of renewable energy applications. To demonstrate the advantages of proposed configuration, the comparative analysis provided with other multilevel configurations in term of a number of switches, gate driver circuits and blocking voltage on switches. The comparison results confirm that the proposed configuration offers less number of components. Moreover, the magnitude of blocking voltage on switches and losses are lower in the proposed configuration. Multicarrier based sinusoidal pulse width modulation scheme is adopted for generating switching signals using dSPACE real-time controller. To validate the performance of proposed topology under steady state and dynamic condition are carried out using simulation on MATLAB/Simulink and experimental implementation. [ABSTRACT FROM PUBLISHER]