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 a symmetrical hybrid nine-level inverter with reduced voltage sensors. A capacitor voltage estimation method is proposed based on phase-shifted PWM by only measuring the total DC-link voltage and the multilevel phase voltage. Under certain conditions, a modified algorithm to further reduce the number of voltage sensors is given. Simulation results are presented to demonstrate these...
As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper...
This paper presents an implementation technique of a high resolution Unipolar Pulse Width Modulator (UPWM) for power inverter applications. Unipolar switched inverter has the advantage of a higher efficiency and lower harmonic distortion. The technique was tested in a 2kW inverter with a typical LC filter and it was achieved a Total Harmonic Distortion below 2%. Simulations and experimental results...
The proposed system explains the inverting operation of DC voltage to AC simply using only three switches. The power demands increases day by day but the sources are limited. A micro grid is benign source of power with various renewable energy resources. The proposed topology has a high frequency rectified sine modulated switch with two symmetrically operated line frequency switches in the front end...
This paper investigates the core losses of an interior permanent magnet synchronous motor (IPMSM) under no-load condition. Two experimental tests have been carried out to observe the impact of the pulse-width modulation (PWM) inverter voltage supply on the core losses. The results show that the high frequency harmonic of the voltage supply is responsible for about 22% of the total core losses.
This paper demonstrates the use of a very large SD Card flash-memory to the control of a three-phase inverter. The digital architecture differs from conventional counter-based implementation because it follows a pre-programmed optimal PWM pattern that is read from a large-size (8MB) memory with magnitude and phase as coordinates. A multi-optimal PWM algorithm is considered to reduce harmonics while...
In the paper multilevel inverters with common mode (CM) voltage compensators are recommended as voltage sources that can constitute the main components of the energy balancing systems for end-user customers. These systems are a part of the modern LV and MV smart grids [1–3]. Measurements have been provided from a power system consisting in multilevel inverters and a passive compensator assuring sinusoidal...
This paper describes a RMS value measurement technique for random jitter. A jittery clock signal is combined with a reference clock signal using an OR operation and an AND operation in sequence, and the pulse width outputs modulated by the amount of the random jitter are used to charge or discharge a capacitor. The voltage at the capacitor, in turn, modulates the frequency of VCO having a current-starved...
A circuit for on-chip measurement of long-term jitter, period jitter, and clock skew, is demonstrated. The circuit uses a single latch and a voltage-controlled delay element, and is evaluated in a stand-alone pad frame. Excellent reproduction of jitter measured by oscilloscope is shown. Measured jitter resolution is 1 ps or better. The circuit is also incorporated into a 2 GHz clock distribution network...
Three-phase 4-switch voltage source inverters are advantageous for reduced number of power switches. For these topologies, space vector pulse width modulation (SVM) methods have been commonly used for controlling the circuit. This paper presents a novel carrier based PWM method for 4-switch inverters, which is simple and flexible. Linear over modulation will be also investigated. The proposed method...
Multilevel inverters have become an attractive alternative for medium voltage and power quality demanding applications. However, like most power converter families, multilevel inverters are controlled with modulation techniques that are conceptually based on nonlinear waveform synthesis assuming constant dc-link voltages. Nevertheless, real applications have load and supply dependent dc-links that...
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.