Demodulation type single‐phase PLL with DC offset rejection

Ahmed, Hafiz; Benbouzid, Mohamed

doi:10.1049/el.2019.3718

Cited by 28 publications

(38 citation statements)

References 17 publications

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“…This can be estimated from the estimated phase-angleφ. For this purpose, we consider the idea used in [14], [38]. In this approach, time derivative of the phase angle can be considered as an approximation of the frequency deviation dynamics.…”

Section: Enhanced Frequency Adaptive Demodulationmentioning

confidence: 99%

Enhanced Frequency Adaptive Demodulation Technique for Grid-Connected Converters

Ahmed

Biricik

Benbouzid

2021

IEEE Trans. Ind. Electron.

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This paper presents an enhanced frequency adaptive demodulation technique for grid-synchronization of grid-connected converters (GCC) in variable frequency condition. Demodulation works by generating demodulated voltages which contain undesired double frequency components. As a result, high-order low-pass filters (LPF) with high cutoff frequency are required to eliminate the undesired components. This reduces the dynamic performance. Frequency adaptive demodulation technique enhances the dynamic performance by rejecting the double frequency components as opposed to filtering, however, at the cost of additional computational complexity. This paper overcomes this problem by using double demodulation without recreating the double frequency component for rejection purpose. This reduces the computational complexity significantly. Suitability of proposed method is verified through numerical simulation and experimental study. Comparative study with existing frequency adaptive demodulation and second-order generalized integrator phase-locked loop (SOGI-PLL) techniques demonstrate the validity and performance improvement by the proposed technique.

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Section: Enhanced Frequency Adaptive Demodulationmentioning

confidence: 99%

Enhanced Frequency Adaptive Demodulation Technique for Grid-Connected Converters

Ahmed

Biricik

Benbouzid

2021

IEEE Trans. Ind. Electron.

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“…various variants of least-square estimation [12], [13], adaptive notch filter (ANF) [14], various variants of delayed signal cancellation (DSC) techniques [15]- [19], linear observer [20]- [23], harmonic oscillators (linear and nonlinear) [24], [25], various variants of phase-locked loop (PLL) [26]- [30], demodulation-based techniques [31], [32], open-loop techniques [33], [34], etc.…”

Section: Introductionmentioning

confidence: 99%

“…Demodulation is another type of technique [31], [32] that got some attention in recent time. Using signal mixing, this technique generate constant signals for frequency estimation purpose.…”

Section: Introductionmentioning

confidence: 99%

Coordinate Transformation-Free Observer-Based Adaptive Estimation of Distorted Single-Phase Grid Voltage Signal

et al. 2020

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This paper studies the phase and frequency estimation problem of single-phase grid voltage signal in the presence of DC offset and harmonics. For this purpose, a novel parameterized linear model of the grid voltage signal is considered where the unknown frequency of the grid is considered as the parameter. Based on the developed model, a linear observer (Luenberger type) is proposed. Then using Lyapunov stability theory, an estimator of the unknown grid frequency is developed. In order to deal with the grid harmonics, multiple parallel observers are then proposed. The proposed technique is inspired by other Luenberger observers already proposed in the literature. Those techniques use coordinate transformation that requires real-time matrix inverse calculation. The proposed technique avoids real-time matrix inversion by using a novel state-space model of the grid voltage signal. In comparison to similar other techniques available in the literature, no coordinate transformation is required. This significantly reduces the computational complexity w.r.t. similar other techniques. Comparative experimental results are provided with respect to two other recently proposed nonlinear techniques to show the dynamic performance improvement. Experimental results demonstrate the suitability of the proposed technique.

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“…However, the L–PLL is sensitive to the presence of DC‐offset. To address this issue, a Lyapunov filter based PLL (LF‐PLL) with improved DC‐offset rejection capability is proposed in [10 ]. However, harmonic rejection capability under nominal and off‐nominal frequency conditions is challenging with this approach.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, demodulation of grid voltage is a potential and widely accepted approach for obtaining the fundamental orthogonal components [5, 7–10 ]. However, the DC‐offset component will become full cycle component in

d q

‐frame [3 ] and odd‐harmonics will be transformed into even harmonics [7, 8 ].…”

Section: Introductionmentioning

confidence: 99%

Modified non-adaptive bandpass filter based phase locked loop

Verma

Jarial

Rao

2020

Electronics Letters

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In this Letter, a demodulation based pre‐filtering technique is proposed for fast detection of the single‐phase grid variables. The estimation of grid voltage parameters is achieved through a Type‐I synchronous reference frame phase‐locked loop (PLL). The modified bandpass filter in the pre‐filtering stage ensure a better rejection of the DC‐offset and harmonics. Thus, the grid variables are estimated rapidly with the help of a simple proportional controller. Consequently, in‐loop filtering burden and the effort required to tune the PLL is minimal. However, steady errors are witnessed in the fundamental amplitude and the phase information which are mitigated by a curve fitting technique. Importantly, the proposed PLL scheme has improved the dynamic performance under off‐nominal frequency conditions with immunity against grid disturbances. The robustness of the proposed algorithm is experimentally verified vis‐à‐vis existing literature.

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Demodulation type single‐phase PLL with DC offset rejection

Cited by 28 publications

References 17 publications

Enhanced Frequency Adaptive Demodulation Technique for Grid-Connected Converters

Enhanced Frequency Adaptive Demodulation Technique for Grid-Connected Converters

Coordinate Transformation-Free Observer-Based Adaptive Estimation of Distorted Single-Phase Grid Voltage Signal

Modified non-adaptive bandpass filter based phase locked loop

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