The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The increase use of renewable dc or battery as a source has further emphasized the importance in efficient design of inverter. This paper discusses a study to determine optimum operating parameters of a commonly used pwm unipolar inverter. Variations on the input voltage level and switching frequency will be investigated to see their impacts on the operation of the inverter as well as harmonics produced...
This paper present three-phase four-wire active filter for power line conditioning (PLC) to improve power quality in the distribution network. The active power filter (APF) is implemented with PWM based current controlled voltage source inverter (VSI). This VSI switching signals are generated through proposed three-level hysteresis current controller (HCC) that achieves significant reduction in the...
Flux harmonic distortion factors (HDFs) of two space vector pulse width modulation (SVPWM) schemes, aimed at sinusoidal output voltage generation with five-phase voltage source inverters, have been evaluated in Part 1 of this paper. Analytical considerations and numerical integration have been applied in order to determine the switching properties of the considered SVPWM methods. It has been shown...
In this paper, various multicarrier pulse width modulation techniques are proposed, which can minimize the total harmonic distortion and enhances the output voltages from five level inverter. Multilevel inverters are important for power electronics applications such as flexible ac transmission systems, renewable energy sources, uninterruptible power supplies and active power filters. Three methodologies...
In this paper comparison of control strategies used for multilevel inverter based shunt active power filter is presented. Recently use of high voltage nonlinear load is considerably increased in industry and elimination of harmonics in HV system has become an important aspect. Implementation of multilevel inverter (MLI) for active power filter (APF) in HV system eliminates use of bulky and high cost...
Pulse width-modulated (PWM) inverters are used more and more to operate electrical machines and to interface renewable energy systems with the utility grid. However, there are abundant high-frequency harmonics in the output voltage of a PWM inverter, which increase the iron losses and result in derating of the machine or transformer connected to them. Predicting the iron losses caused by the PWM supply...
In this paper, various novel pulse width modulation techniques are analysed, which can enhances the output voltages from five level inverter to multilevel topologies. Multilevel inverters are important for power electronics applications such as flexible ac transmission systems, renewable energy sources, uninterruptible power supplies and active power filters. Three methodologies adopting the constant...
This paper presents an improved PWM strategy for three-phase inverters, especially suited for use at low ratios of switching frequency to fundamental output frequency. The method of third-harmonic injection is used to ensure maximum utilisation of the DC bus voltage. Implementation issues for the new modulation strategy are discussed. A comparison with a conventional, regularly sampled PWM is presented,...
The configuration of a single-phase AC-DC converter plus a three-phase inverter traction system has been widely applied in high-speed railway electrical drive systems. With the single-phase power feeder, the instantaneous power is fluctuating at twice of the power line frequency, and so is the DC-link voltage. Associated with the DC-link voltage fluctuation is a severe problem, when the electric frequency...
This paper presents a study of determining the optimum operating parameters of a unipolar PWM inverter. Variations on the input voltage level and switching frequency will be investigated to see their impacts on the operation of the inverter and harmonics produced. Results through experimental approach show that careful selections of inverter parameters yield inverter's operation with highest efficiency...
A modified Third Harmonic Injection PWM (THI-PWM) modulator that reduces output harmonics has been presented in this paper. The modulator is combined with harmonic injection and phase shifting parts in Simulink design. The harmonic injection ratios have been analysed according to harmonic amplitude ratio of third harmonic to fundamental amplitude. The designed modulator is capable to minimize the...
This paper proposes the development of dodecagonal (12-sided) space vector diagrams from cascaded H-Bridge inverters. As already reported in literatures, dodecagonal space vector diagrams have many advantages over conventional hexagonal ones. Some of them include the absence of 6n±1, (n=odd) harmonics from the phase voltage, and the extension of the linear modulation range. In this paper, a new power...
A number of PWM techniques have been developed in recent times for five-phase voltage source inverters (VSIs), which enable sinusoidal output voltage generation. Relatively little attention has been however paid to the current ripple caused by these PWM methods. This paper investigates stator current ripple (THD), caused by the switching harmonics, for two space vector PWM (SVPWM) techniques that...
In this paper, cascade H-bridge converter with Variable-Frequency Carrier Bands PWM method (VFCB-PWM) has been proposed, which is the combination of cascade structure and CPS-SPWM method. High equivalent switching frequency can be obtained with low switching frequency devices. Such advantages as simple structure, wide bandwidth and good transient response can be obtained in large power equipment....
This paper deals with a design method of LCL filter for grid-connected three-phase PWM voltage source inverters (VSI). By analyzing the total harmonic distortion of the current (THDi) in the inverter-side inductor and the ripple attenuation factor of the current (RAF) injected to the grid through the LCL network, the parameter of LCL can be clearly designed. The described LCL filter design method...
Multilevel inverters with a large number of steps can generate high quality voltage waveforms, good enough to be considered as suitable voltage source generators. A modified Sinusoidal Pulse Width Modulation (SPWM) modulator with phase disposition that increases output waveform up to 7-level while reducing output harmonics is presented in this paper. The proposed modulation technique can easily be...
For improving the dynamic response of the system, most of the pwm voltage source inverters are operating with inner current control loop. The application includes high performance ac drives, active filters and power supplies etc. Recently pwm voltage source inverters are employed in grid connected distributed power generating systems in order to provide secure and reliable power to the utility grid...
The static synchronous compensator(STATCOM) using power electronics as a shunt device of the Flexible AC Transmission Systems (FACTS) is attracting an increasing interest in power system research and in electric utilities. This paper proposes a novel multi-level structure topology with zigzag transformer for three-level inverter used in STATCOM. Moreover, selective harmonic elimination pulsewidth...
Characteristics and application of multi-phase space vector PWM (SVPWM) technology based on multi-phase permanent magnet synchronous motor (PMSM) variable speed system with high performance are presented, and experimental performances for motor and inverter are evaluated. The special PWM-Cycle of each interregnum for field oriented control (FOC) is be analyzed, and the improved strategies for performances...
Current-controlled pulse width modulated voltage source inverters are most widely used in high performance AC drive systems, because they provides high dynamic response. This paper presents a comparative study between the hysteresis and delta modulated current controllers for three-phase voltage source inverter. The hysteresis controller provides excellent dynamic performance because it acts quickly...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.