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 Direct Torque Control is a technique increasingly used for the ordering of the invertors and synchronous machine. This system can be regarded as a hybrid dynamic system whose continuous component is the permanent magnet synchronous machine and the discrete component, the inverter of tension. In this article, we propose a modeling of this whole by a system with discrete events. This model is then...
This paper intends to present a model of power transformers used in simulation of power inverters. Electromagnetic induction refers to the phenomenon by witch electric current is generated in a closed circuit by the fluctuation of current in another circuit placed next to it. For modeling of power transformers, we implemented a Matlab software, based on mathematical equations who describe the functionality...
This paper presents a discrete-time predictive control strategy for a voltage-source inverter based on computation of a deadbeat control law and its approximating suboptimal voltage vector at every sampling interval. The controller, in addition to compensating for the inherent delay in the system, employs a simple prediction filter to suppress the disturbance caused by the back-EMF voltages and improve...
The output voltage of an inverter is often assumed proportional to the drive modulation signal. However, in practice the inverter presents nonlinear characteristics that may significantly affect the output voltage, and this may be critical in the context of sensorless drives and parameter identification. Nowadays, several solutions exist to compensate for the nonlinear behaviour of the inverter. Nevertheless,...
In this paper a speed sensorless ac drive with inverter and output LC filter is proposed. A nonlinear, decoupled field oriented control algorithm with a flux and speed close-loop observer is used. In spite of using LC filter on the inverter output, the sensorless system works precisely. That result are obtained as a result of the appropriate estimation and control system use. The theory, simulation,...
Several proposals for using of power derived from regenerative braking in railway systems are available. We present an energy recovery system with feedback to the distribution grid based on a new converter topology; the dimensioning methodology of the system is based on real data intake and validated simulations. The new converter topology presented is based on the connection in cascade of a DC/DC...
The inverter-fed induction motor drive system may become unstable at low frequencies and light load. Taking the inverter-fed five phase induction motor drive system as an example, the small disturbance mathematic model of whole system is deduced, based on small disturbance model of induction motor and switching model of inverter system, the three-dimensional unstable region is presented and discussed...
This paper presents the analysis and simulation of a three-phase voltage-source inverter. The inverter is driven using space vector modulation and it has a dead time of 2 μs. During this simulation, power losses on the power electronic switches are calculated and used on a thermal model. The thermal conduction equation was solved to predict the temperature distribution. The finite element numerical...
The increasing presence of single-phase distributed generators and unbalanced loads in the electric power system may lead to unbalance of the three phase voltages, resulting in increased losses and heating. To decrease this voltage unbalance problem three-phase four-wire inverter-connected distributed generation units may be used. In this paper, the influence of the control strategy of three-phase...
This paper deals with modeling, control and co-simulation of a single-phase single-stage Grid-interactive photovoltaic (PV) system with active filter functions. Single-phase PV systems are the most prevalent in roof-top configurations. In this paper, the modeling of a PV array with maximum power point tracking is performed in MATLAB/Simulink. The developed PV array model may be directly connected...
Nowadays high quality power is essential for medical, research and industrial applications to produce good quality results and analysis. In this paper, an attempt has been made to improve the quality of power. A single phase seven level cascaded multi level inverter with identical dc supply is designed to reduce the harmonic components of the output voltage. Genetic algorithm optimization technique...
This paper focuses on the study of a two-stage, multi-string photovoltaic (PV) system connected by a common DC bus to a centralized inverter, interfaced with a utility grid. The distribution network model, load model and DC bus model are used for simulation. PV system exhibits non-linear v-i characteristics and an intermediate boost converter is employed to operate the PV array at its maximum power...
This paper proposes the maximum power tracking from the Photovoltaic system, which is interfaced with utility grid through a three phase inverter, by using a fuzzy logic controller. In this arrangement, three phase step up transformer is used to synchronize the inverter output with the grid ratings. Controller tracks and feeds maximum power to the utility grid. The linguistic variables have been selected...
Nowadays high quality power is essential for medical, research and industrial applications to produce good quality results and analysis. In this paper, an attempt has been made to improve the quality of power. A single phase seven level cascaded multi level inverter with identical dc supply is designed to reduce the harmonic components of the output voltage. Genetic algorithm optimization technique...
Three transformerless converters for three phase solar applications are compared concerning efficiency, leakage current and mechanical volume. The investigated topologies are the voltage source inverter (VSI), the three level neutral point clamped (NPC) inverter and the z-source inverter (ZSI). Therefore the topologies are introduced and the working principles are explained. The power losses, the...
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 a model to simulate the electrical behavior of real single-phase grid-connected photovoltaic inverters. The implemented control strategy includes both voltage and current control loops. This control strategy allows to simulate the injected current waveform under power dynamics or grid voltage disturbances. Irradiance changes and Maximum Power Point Tracker are also included. Inverter...
The paper discusses the state of the art of implementations and applications of sensorless control in industrial frequency inverters. Implementations for speed and position controlled drives are shown using either EMF based flux estimators or an Extended Kalman Filter (EKF) with signal injection to evaluate the saliencies of the machines for speed and position detection. Applications are presented...
Linear programming models are formulated and solved to determine the switching angles that optimally minimize the values of the undesired harmonics in cascaded multilevel inverters with staircase output voltage waveform. Three cases are discussed. Case 1 assumes fixed equal values of the input dc voltages. A mixed integer linear programming (MILP) model is applied. In case 2 this model is modified...
Since there's a biggish output ripple in current direct torque's control, we design a direct torque control system for three-level inverters used in asynchronous motors by analyzing the operational principle of the diode clamped three-level inverters, and simulation is done as well. Ripples of the torque and the rotational speed of the motor can be deduced effectively, and a stable output and a good...
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.