Yasemin Önal

DSP based embedded code generation for PMSM using sliding mode controller

This study presents a Digital Signal Processor (DSP) based embedded code generation which is obtained automatically in PSIM software for Permanent Magnet Synchronous Motor (PMSM) control system. The simulation model of the PMSM control system is developed in PSIM environment using Motor Control Blocks and Embedded Target for TI 28335 block. This control block diagram is send to SimCoder to generate C-code that is ready to run on the DSP hardware, SimCoder also creates the complete project files for the TI Code Composer Studio development environment where the code will be compiled, linked, and uploaded to the DSP using High Voltage Motor Control-PFC Kit. So, embedded code generation provides a very quick way to design a motor drive system from user specifications also programming greatly simplifies the generation, prototyping and modification of DSP based design, thus decreasing the development cycle time.

Analysis of voltage flicker using Hilbert-Huang Transform

Hilbert Huang Transform (HHT), which was proposed by Huang and developed by Flandrin and his group, is a new signal processing method that can be used in the analysis of nonlinear and nonstationary signals. This study suggests an approach of using Hilbert Huang Transform to measure the voltage flicker in power systems. In the suggested method, voltage signal is decomposed into Emprical Mode Decomposition EMD and Intrinsic Mode Function IMF components. These components are used in the calculation of the frequency and amplitude of voltage flicker. The clear success of EMD in depicting envelope variations of a sinusoidal waveform has been the main motivation for the adoption of HHT in flicker analysis. Simulations are done by using input signal modulated with single flicker frequencies and multi flicker frequencies and input signals which include harmonic. Simulations show that the method may be used in voltage flicker analyse and gives good results.

Hilbert–Huang Transform Based Approach for Measurement of Voltage Flicker Magnitude and Frequency

Abstract Voltage flicker is a non-stationary waveform for which direct spectral analysis is not appropriate. To overcome this difficulty, a Hilbert–Huang transform based technique is proposed here. Hilbert–Huang transform is a new signal processing method that can be used in the analysis of non-linear and non-stationary signals. In the suggested method, the recorded voltage signal is decomposed into Hilbert–Huang transform components, namely the empirical mode decomposition and intrinsic mode function components. These components are used in the calculation of the frequency and amplitude of voltage flicker. The clear success of empirical mode decomposition in depicting envelope variations of a sinusoidal waveform has been the main motivation for the adoption of Hilbert–Huang transform in flicker analysis. Simulations are performed over waveforms, including single- and multiple-flicker frequencies and flicker with harmonic, voltage sag, and voltage swell. The waveforms are selected as pure sinusoids, as well as harmonically rich voltage waveforms. Simulation results show that the proposed methodology constitutes a plausible way to analyze voltage flickers, making it an alternative to the available flicker analysis tools.AbstractVoltage flicker is a non-stationary waveform for which direct spectral analysis is not appropriate. To overcome this difficulty, a Hilbert–Huang transform based technique is proposed here. Hilbert–Huang transform is a new signal processing method that can be used in the analysis of non-linear and non-stationary signals. In the suggested method, the recorded voltage signal is decomposed into Hilbert–Huang transform components, namely the empirical mode decomposition and intrinsic mode function components. These components are used in the calculation of the frequency and amplitude of voltage flicker. The clear success of empirical mode decomposition in depicting envelope variations of a sinusoidal waveform has been the main motivation for the adoption of Hilbert–Huang transform in flicker analysis. Simulations are performed over waveforms, including single- and multiple-flicker frequencies and flicker with harmonic, voltage sag, and voltage swell. The waveforms are selected as pure sinusoids, as wel...

Bridgeless SEPIC PFC converter for low total harmonic distortion and high power factor

There is a need to improve the power quality of the grid as well as the power factor implied on the grid due to the nonlinear loads connected to it. A new single phase bridgeless AC/DC power factor correction (PFC) topology to improve the power factor as well as the total harmonic distortion (THD) of the utility grid is proposed in this research. By eliminating the input bridge in conventional PFC converters, the control circuit is simplified; the total harmonics distortion THD and power factor PF are improved. The controller operates in multi loop fashion as the outer control loop calculates the reference current through innovative filtering and signal processing. Inner current loop generates PWM switching signals through the PI controller. Analytical derivation of the proposed converter is presented in detail. Performance of the proposed PFC topology is verified for prototype using PSIM circuit simulations. The experimental system is developed, and the experimental results agree with simulation results.

A new single switch bridgeless SEPIC PFC converter with low cost, low THD and high PF

In this paper, a new single switch bridgeless AC/DC power factor correction PFC converter topology to achieve high PF and low THD is proposed. The proposed converter is based on the single ended primary inductance converter SEPIC topology. The SEPIC converters can operating from an input voltage that is greater or less than the output voltage. The proposed PFC uses only one active switch to PFC process together hoping higher PF and low THD. Besides the application cost is less than conventional bridgeless SEPIC PFC, in where two active switching devices are necessary. In order to verify the performance comparison between the proposed and the conventional SEPIC PFC, simulation circuit with 100W is install in PSIM. The simulation results are presented to demonstrate the feasibility of the proposed converters. The results show that the proposed bridgeless SEPIC PFC perfectly succeeds PFC operation using a single active switch.

Detection of voltage flicker and voltage harmonic using Hilbert Huang Transform

Hilbert Huang Transform, which was suggested by Huang and improved by Flandrin and his group, is a new signal processing method. The analysis of nonlinear and non stationary signals can use HHT. This paper deals with the use of a HHT to detect and analyze voltage harmonics and flickers. In this method, the recorded harmonic signal and flicker signal are decomposed into Intrinsic Mode Functions using the Emprical Mode Decomposition. The frequency and amplitude of voltage harmonics and voltage flickers are obtained of IMF components by using Hilbert Transform HT. The clear success of EMD in defining envelope variations of a sinusoidal waveform has been the main motivation for the adoption of HHT in harmonic and flicker analysis. Simulations are performed over waveforms including voltage harmonics and voltage flickers. The waveforms are selected as pure sinusoids. Simulation results show that the suggested methodology constitutes a credible way to analyze voltage harmonics and voltage flickers.

Short-term flicker severity index calculation using Hilbert-Huang Transform

This article proposes an approach to calculate the short term flicker magnitude (Pst) using Hilbert-Huang Transform (HHT). HHT is an approach which is commonly used in the analysis of nonlinear and nonstationary signals. Since flicker corresponds to a variation of the envelope of a sinusoidal voltage waveform, the utilization of HHT is reasonable. The magnitude of the short term flicker (Pst) is an important power quality parameter that is established by the International Electrotechnical Commission (IEC). In the proposed method, the HHT parameters such as Empirical Mode Decomposition (EMD) and Intrinsic Mode Function (IMF) are evaluated. The short term flicker magnitude (Pst) is claimed to be determined as a nonlinear and statistical function of the waveform magnitude and frequencies obtained by EMD, which is known to succeed in determination of envelope variations. The proposed method is also experimentally observed to precisely determine the (Pst) value.