A novel approach for synthesising sinus waveforms at power level

Şedele, Serkan Paki
In variable speed motor drive and uninterruptible power supply (UPS) applications, taditional method is to employ some kind of a modulation technique at a high frequency typically 6 kHz to 20 kHz range. In these modulation techniques, the switches are hard switched. The result is application of a series of pulses to the load, and if the load is inductive, sine wave current flows into the load. Hard and rapid switching causes a voltage waveform with a very high dv/dt (rate of change in voltage) causing high EMI problems, reduced life expectancy of the motor and additional losses. So a power supply generating pure sinusoidal voltage waveform is very desirable. In industry some low pass filters called sinusoidal filters, are used at the output of the inverters but this comes with additional cost and bulky filter elements. In this study, a novel approach for generating power level sinusoidal waveforms is proposed. The basic structure is a DC-DC converter that produces a rectified DC-link at its output and an H-bridge inverter that inverts the rectified sinusoids to form a sinusoidal voltage. Main advantages of the circuit are that the H-bridge inverter switches have no switching stresses, they are switched at low frequency so the reliability is increased. Throughout the study different circuit topologies have been investigated and the analysis of the chosen topologies is supported with computer simulations. The system is then set up in the laboratory. In order to prove of the concept, only a single phase inverter has been investigated at steady state conditions. Efficiency, distortion level, magnitude error and device stresses have been obtained. The results indicate that the proposed configuration is very promising.


GOKMEN, A; YALCIN, S (1992-01-01)
A versatile interface card for Apple IIe computer and various peripheral devices are designed to control instruments which generates transient signals like in graphite furnace atomic spectrometer. The interface card consists of a multiplexed analog-to-digital converter, a digital-to-analog converter, and a timer/counter chip. The timer/counter chip with 16 built-in registers can be programmed in many modes which provides a time base for real-time measurements. A stepper motor runs under the control of ti...
An asynchronous system design and implementation of an FPGA
Ayyıldız, Nizam; Güran, Hasan; Department of Electrical and Electronics Engineering (2006)
Field Programmable Gate Arrays (FPGAs) are widely used in prototyping digital circuits. However commercial FPGAs are not very suitable for asynchronous design. Both the architecture of the FPGAs and the synthesis tools are mostly tailored to synchronous design. Therefore potential advantages of the asynchronous circuits could not be observed when they are implemented on commercial FPGAs. This is shown by designing an asynchronous arithmetic logic unit (ALU), implemented in the style of micropipelines, on th...
A Novel Software for Automatic Calibration Factor Measurement of RF Power Sensors
Kizilbey, Oguzhan; Arslan, Murat; Bayrak, Yusuf; Çetinkaya, Anıl; Yugruk, Aydin; Danaci, Erkan (2022-01-01)
© 2022 IEEE.In this letter, a software for calibration factor (CF) measurement of radio frequency (RF) power sensors (PS) by using VNA-based direct comparison transfer method (VBDCTM) was developed on C# platform. Measurements were performed between 10 MHz and 18 GHz frequency range. When the calibration factors calculated with conventional CF measurement method and novel software were compared, a maximum difference of 4.56% was found in the 10 MHz - 18 GHz frequency band. Therefore, the automatic CF measur...
A reality check for radiometric camera response recovery algorithms
Akyüz, Ahmet Oğuz (Elsevier BV, 2013-11-01)
The radiometric response of a camera governs the relationship between the incident light on the camera sensor and the output pixel values that are produced. This relationship, which is typically unknown and nonlinear, needs to be estimated for applications that require accurate measurement of scene radiance. Until now, various camera response recovery algorithms have been proposed each with different merits and drawbacks. However, an evaluation study that compares these algorithms has not been presented. In...
Impact of defected ground structures on the bandwidth of quarter wave impedance transformers and branch line hybrids
Polater, Ahmet Mert; Nesimoglu, Tayfun (Wiley, 2016-05-01)
In this article, impedance transformers and branch line hybrids are selected to demonstrate the impact of defected ground structures on the operational bandwidth of microwave circuits. Three different branch line hybrids are studied with simulations and laboratory measurements, these are; a standard branch line hybrid, one using tapered lines and another one using both tapered lines and DGS. Based on these results, an optimum design in terms of location, size and number of DGS was proposed to achieve the wi...
Citation Formats
S. P. Şedele, “A novel approach for synthesising sinus waveforms at power level,” M.S. - Master of Science, Middle East Technical University, 2004.