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.
This paper presents an analytical method developed to explain the mechanism of harmonic transfer between the ac and dc sides of a single-phase inverter in a PV microgrid. The model explains how the feed-forward of the current from the ac side of the PV-inverter into the control system, causes even harmonics on the dc voltage. It further shows how the controller's feedback of the dc bus voltage carrying...
This paper will discuss the modeling of three-phase four wire active power filter (APF) for Quaid-e-Awam University College of Engineering Sciences and Technology (QUCEST) Campus at Larkana, Pakistan. The control strategy of the APF is based on the Unit Vector Template (UVT) method and Instantaneous Reactive Power (IRP) theory. The function of UVT method is for obtaining the voltage signals for the...
High order harmonic flux and current of permanent magnet synchronous motor (PMSM) are generated by the distortion of air-gap magnetic field and the nonlinear characteristics of inverter, resulting in the ripple of electromagnetic torque. In this paper, a novel harmonic compensation algorithm was proposed to solve this problem. Based on the harmonic model of the PMSM, harmonic voltage is injected to...
The core issues with Distributed Generation (DG) systems of today are the insertion of power quality threats, harmonic distortions to the main stream power system and inefficient power sharing leading to power fluctuation problem. This paper effectively sorts out the causes of power fluctuation in islanded mode of operation of micro-grids and presents an effective method for their optimum compensation...
In recent years, increasing concerns about climate change and the liberalisation of energy market have provided the necessary impetus for a revolutionary restructuring of the electricity network at every level, namely production, transmission and distribution. Increased electricity production from renewable energy sources (RES) coupled with energy efficiency lie at the heart of the ambitious targets...
The purpose of this paper is to provide low cost, high power quality and high efficiency solutions for grid-connected inverters. Compared with bipolar switched inverters, unipolar switched inverters have the advantages of higher efficiency due to reduced switching frequency and low iron losses of inductor in output filter. However, unipolar inverters produce large harmonic distortion due to the dead-time...
This paper presents an inverter topology based on series-voltage-action (SVA) to be employed in single-phase motor drive systems. Such topology will be called as single-phase SVA inverter. The single-phase SVA inverter presents some advantages over the traditional ones, such as output voltage higher than the dc-link voltage and lower THD of the motor voltage due to high number of levels generated...
This paper presents the design and analysis of both the active and reactive power control of a single-phase voltage source inverter (VSI) for grid-connected photovoltaic (PV) system. The proposed method is based on vector control of power by decoupling control of the active and reactive current components to feed the active and reactive power to the grid. The aim of this research is to control power...
This paper presents a new methodology for the operation and control of a single-phase current-source (CS) Boost Inverter, considering that the conventional current-source inverter (CSI) has a right-half-plane (RHP) zero in its control-to-output transfer function, and this RHP zero causes the known non-minimum-phase effects. In this context, a special design with low boost inductance and a multi-loop...
We introduce a novel analytical approach to the evaluation of harmonic content in multi-level inverters. An analytical formula for the phase voltage total harmonic distortion (THD) of any multi-level pulse-width modulation (PWM) signal is introduced. As opposed to conventional THD expression where full spectral knowledge of the signal is required, the proposed formula depends only on fundamental amplitude,...
In this paper, the development of three-phase renewable energy inverter by using the dSPACE DS1104 digital signal processing controller board is presented. The board enables the MATLAB/Simulink model linking to the hardware. The standalone voltage source inverter's control system which is implemented in the DS1104 board utilizes a digital proportional integral controller to stabilize its 50Hz sinusoidal...
In recent years, the increase of energy demand and the problems of fossil-fuel sources due to their environmental pollution and future shortages, have led to the development of technologies need to use non-polluting alternative energy sources such as solar and wind sources. Growing demand, advancements in semiconductor technology and magnetic materials such as high frequency inductor cores, has a...
Model Predictive Direct Torque Control (MPDTC) is a recent computational control methodology that combines the merits of Model Predictive Control (MPC) with the ones of Direct Torque Control (DTC). Specifically, with respect to standard DTC, the converter's switching frequency and/or losses are considerably reduced, while at the same time the Total Harmonic Distortion (THD) levels of the phase currents...
This paper applies the selective harmonic elimination technique to 5-phase, 2-level inverters to assess the ability of the technique to eliminate specific harmonics. Whilst the technique is well-known, there is little information on its application to five-phase drives, where there are specific and important differences to three-phase counterparts. This includes the need to eliminate different harmonics,...
This paper presents the analysis, modelling and control model of the electric part of a grid connected photovoltaic generation system. The model contains a detailed representation of the main components of the system that are the solar array, and the grid side multilevel neutral point clamped (NPC) voltage source inverter (VSI). In order to extract the maximum amount of from the photovoltaic generator,...
Multilevel inverters introduce harmonic to the network, beside their enormous advantages. THD is one of the most important indexes to evaluate harmonic contents of waveforms. Conventional method of line voltage THD calculation gives approximate answers but its accurate value is important. In this paper, a series of analytical formula is found to calculate line voltage THD of 5-level inverter with...
A new generation of DC to AC inverters which is called Multilevel Inverter, has many industrial applications, especially in high-voltage and high-power. In spite of nearly sinusoidal waveform, multilevel inverters produce noticeable harmonic content. THD is normally used as a benchmark to evaluate harmonic contents. THD is one of important factors to produce losses in devices such as induction motors,...
Inverters are power devices used for many industrial applications such as power conversion, the speed control of induction motors etc. When a magnetic device is energized by an inverter power supply, its magnetic core is subjected to additional core losses due to harmonic contents. One solution to this problem may be the selective harmonic elimination based on the simultaneous solution of non-linear...
It is difficult to obtain a more precise mathematical model of parallel-inverter system with a nonlinear load. Nonlinear load is the general factor which affects output voltage total harmonic distortion (THD) and current sharing. But fuzzy controller can control well without a precise mathematical model. Master-slave control is used to control the parallel-inverter system in this paper. The voltage...
This paper presents a generalized Model Predictive Direct Torque Control scheme with an extended horizon, which is composed of multiple hinges (groups of switch transitions) linked by several extrapolation segments. The controller's performance is further enhanced by minimizing the switching losses in the inverter. Initial results suggest that with respect to state of the art Direct Torque Control,...
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.