scholarly journals A unified method for signal parameter estimation of arbitrarily distorted single-phase grids with DC-offset

2020 ◽  
Author(s):  
Christoph Hackl ◽  
Markus Landerer
Keyword(s):  
Fundamental Frequency ◽  
Single Phase ◽  
Adaptive Observer ◽  
Pole Placement ◽  
Estimation Methods ◽  
Dc Offset ◽  
Low Pass ◽  
Harmonic Components ◽  
Low Pass Filters ◽  
Unified Method

A unified method is presented which allows to<br>estimate all harmonic components, DC-offset and fundamen-<br>tal frequency in arbitrarily distorted single-phase grids us-<br>ing a frequency-adaptive observer (FAO) consisting of modi-<br>fied Second-Order Generalized Integrators (mSOGIs), a DC-<br>Integrator (DCI) and a modified Frequency Locked Loop<br>(mFLL). DCI and mSOGIs are tuned by pole placement which allows for an arbitrarily fast detection of DC-offset and harmonic components if the fundamental frequency is known. If the fundamental frequency must be estimated as well, a mFLL with Gain Normalization (GN), Rate Limitation (RL), Anti-Windup (AW) strategy and low-pass filters (LPF) must be employed. The effectiveness of the proposed FAO is validated by experimental results and its enhanced performance is shown by comparisons<br>to existing estimation methods.

scholarly journals A unified method for signal parameter estimation of arbitrarily distorted single-phase grids with DC-offset

2020 ◽  
Author(s):  
Christoph Hackl
Keyword(s):  
Fundamental Frequency ◽  
Single Phase ◽  
Adaptive Observer ◽  
Pole Placement ◽  
Estimation Methods ◽  
Dc Offset ◽  
Low Pass ◽  
Harmonic Components ◽  
Low Pass Filters ◽  
Unified Method

A unified method is presented which allows to<br>estimate all harmonic components, DC-offset and fundamen-<br>tal frequency in arbitrarily distorted single-phase grids us-<br>ing a frequency-adaptive observer (FAO) consisting of modi-<br>fied Second-Order Generalized Integrators (mSOGIs), a DC-<br>Integrator (DCI) and a modified Frequency Locked Loop<br>(mFLL). DCI and mSOGIs are tuned by pole placement which allows for an arbitrarily fast detection of DC-offset and harmonic components if the fundamental frequency is known. If the fundamental frequency must be estimated as well, a mFLL with Gain Normalization (GN), Rate Limitation (RL), Anti-Windup (AW) strategy and low-pass filters (LPF) must be employed. The effectiveness of the proposed FAO is validated by experimental results and its enhanced performance is shown by comparisons<br>to existing estimation methods.

scholarly journals A unified method for signal parameter estimation of arbitrarily distorted single-phase grids with DC-offset

2020 ◽  
Author(s):  
Christoph Hackl ◽  
Markus Landerer
Keyword(s):  
Fundamental Frequency ◽  
Single Phase ◽  
Adaptive Observer ◽  
Pole Placement ◽  
Estimation Methods ◽  
Dc Offset ◽  
Low Pass ◽  
Harmonic Components ◽  
Low Pass Filters ◽  
Unified Method

A unified method is presented which allows to<br>estimate all harmonic components, DC-offset and fundamen-<br>tal frequency in arbitrarily distorted single-phase grids us-<br>ing a frequency-adaptive observer (FAO) consisting of modi-<br>fied Second-Order Generalized Integrators (mSOGIs), a DC-<br>Integrator (DCI) and a modified Frequency Locked Loop<br>(mFLL). DCI and mSOGIs are tuned by pole placement which allows for an arbitrarily fast detection of DC-offset and harmonic components if the fundamental frequency is known. If the fundamental frequency must be estimated as well, a mFLL with Gain Normalization (GN), Rate Limitation (RL), Anti-Windup (AW) strategy and low-pass filters (LPF) must be employed. The effectiveness of the proposed FAO is validated by experimental results and its enhanced performance is shown by comparisons<br>to existing estimation methods.

Pitch related to spectral edges of broadband signals

1992 ◽  
Vol 336 (1278) ◽  
pp. 375-382 ◽  
Keyword(s):  
Fundamental Frequency ◽  
Basilar Membrane ◽  
Comparison Tone ◽  
Harmonic Signals ◽  
Wide Range ◽  
Spectral Components ◽  
Neuronal Processes ◽  
Low Pass ◽  
Harmonic Components ◽  
Hearing System

A complex tone often evokes a pitch sensation associated with its extreme spectral components, besides the holistic pitch associated with its fundamental frequency. We studied the edge pitch created at the upper spectral edge of complexes with a low-pass spectrum by asking subjects to adjust the frequency of a sinusoidal comparison tone to the perceived pitch. Measurements were performed for different values of the fundamental frequency and of the upper frequency of the complex as well as for three different phase relations of the harmonic components. For a wide range of these parameters the subjects could adjust the comparison tone with a high accuracy, measured as the standard deviation of repeated adjustments, to a frequency close to the nominal edge frequency. The detailed dependence of the matching accuracy on temporal parameters of the harmonic complexes suggests that the perception of the edge pitch in harmonic signals is related to the temporal resolution of the hearing system. This resolution depends primarily on the time constants of basilar-membrane filters and on additional limitations due to neuronal processes.

scholarly journals DC Offset Error Compensation Algorithm for PR Current Control of a Single-Phase Grid-Tied Inverter

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2308 ◽  
Author(s):  
Jae Lee ◽  
Seon-Hwan Hwang
Keyword(s):  
Fundamental Frequency ◽  
Error Compensation ◽  
Single Phase ◽  
Detection Method ◽  
Current Control ◽  
Dc Offset ◽  
Phase Current ◽  
Compensation Algorithm ◽  
Dc Component ◽  
Offset Error

In a single-phase grid-tied inverter, the direct current (DC) offset error included in the measured grid side phase current has various causes, such as a non-ideal current sensor, unbalanced power supply of an operational amplifier, and nonlinear features of analog components in interface circuits, etc. If the DC offset error is included in the measured current, it causes the secondary harmonic of fundamental frequency and the DC component in grid phase current which result in degradation of inverter performance. In this paper, a theoretical detection method of the secondary harmonic of the fundamental frequency and a DC component in grid phase current for a proportional-resonant (PR) current control system is introduced. Based on the detection method, an algorithm for compensating DC offset error is also presented for single-phase grid-tied inverters. Simulation results and experimental verification of the DC offset error compensation algorithm are shown in this paper.

scholarly journals Harmonic Suppression Strategy in Single-phase SPWM Based on Mixed Integer Nonlinear Programming

2019 ◽  
Vol 13 (5) ◽  
pp. 22
Author(s):  
Lubin Wu ◽  
Ziquan Liang ◽  
Weihua Li ◽  
Xiaoteng Wang
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Mixed Integer ◽  
Harmonic Suppression ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Integer Nonlinear Programming ◽  
Low Pass ◽  
Harmonic Components ◽  
Suppression Strategy

In single-phase bipolar SPWM inverter circuit, the output voltage contains high content of harmonic components. To solve this problem, we build a model of output voltage in single-phase SPWM bipolar inverter based on SPWM theory and Fourier series theory. Through theoretical analysis, calculation and plotting, we work out the distribution of harmonic in output voltage, investigate the relationship between amplitude modulation (AM) depth and harmonic components and finally determine a proper amplitude modulation depth to efficiently reduce harmonic components. To further reduce harmonic components of output voltage, we use LC low-pass filter. Then, based on the mathematical model of the filter and the distribution law of harmonics, we establish a mixed integer nonlinear programming to fully suppress harmonics and reduce switching losses. After searching for two times based on genetic algorithm, we work out the best frequency-modulation ratio and LC low-pass filter parameter. Finally in simulation, total harmonic distortion is reduced from 213.47 percent to 0.16 percent after harmonic suppression strategy implemented. The result has proved the effectiveness of the harmonic suppression strategy we applied, which can be used as a reference for output voltage harmonic elimination in single-phase SPWM inverter.

Ku/Ka-band Compact Orthomode Junction with Low Pass Filters for High Power Applications

2015 ◽  
Vol E98.C (2) ◽  
pp. 156-161
Author(s):  
Hidenori YUKAWA ◽  
Koji YOSHIDA ◽  
Tomohiro MIZUNO ◽  
Tetsu OWADA ◽  
Moriyasu MIYAZAKI
Keyword(s):  
High Power ◽  
Ka Band ◽  
Low Pass ◽  
Low Pass Filters

Mathematical Model of Low-Pass Filters

2011 ◽  
Vol 5 (2) ◽  
pp. 155-162
Author(s):  
Jose de Jesus Rubio ◽  
Diana M. Vazquez ◽  
Jaime Pacheco ◽  
Vicente Garcia
Keyword(s):  
Mathematical Model ◽  
Low Pass ◽  
Low Pass Filters
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