An Optimized Implementation of Phase Locked Loops for Grid Applications

Freijedo, Francisco D.; Yepes, Alejandro G.; López, Oscar L.; Fernández-Comesaña, Pablo; Doval-Gandoy, Jesús

doi:10.1109/tim.2011.2122550

Cited by 56 publications

(27 citation statements)

References 24 publications

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“…The undesired oscillations caused by abnormal and faulty grid conditions can be mitigated using adaptive or notch filters in the PLL algorithm [63][64][65][66][67]. Based on the Schur lattice structure in [64], adaptive notch filters with infinite impulse responses are implemented to improve the performance of the conventional SRF under variable frequency and unbalanced grid voltage conditions.…”

Section: Adaptive or Notch Filtering Techniquesmentioning

confidence: 99%

Three-phase phase-locked loop synchronization algorithms for grid-connected renewable energy systems: A review

Ali

Christofides

Hadjidemetriou

et al. 2018

Renewable and Sustainable Energy Reviews

149

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The increasing penetration of distributed renewable energy sources (RES) requires appropriate control techniques in order to remain interconnected and contribute in a proper way to the overall grid stability, whenever disturbances occur. In addition, the disconnection of RES due to synchronization problems must be avoided as this may result in penalties and loss of energy generation to RES operators. The control of RES mainly depends on the synchronization algorithm, which should be fast and accurately detect the grid voltage status (e.g., phase, amplitude, and frequency). Typically, phase-locked loop (PLL) synchronization techniques are used for the grid voltage monitoring. The design and performance of PLL directly affect the dynamics of the RES grid side converter (GSC). This paper presents the characteristics, design guidelines and features of advanced state-of-the-art PLL-based synchronization algorithms under normal, abnormal and harmonically-distorted grid conditions. Experimental tests on the selected PLL methods under different grid conditions are presented, followed by a comparative benchmarking and selection guide. Finally, corresponding PLL tuning procedures are discussed.

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Section: Adaptive or Notch Filtering Techniquesmentioning

confidence: 99%

Three-phase phase-locked loop synchronization algorithms for grid-connected renewable energy systems: A review

Ali

Christofides

Hadjidemetriou

et al. 2018

Renewable and Sustainable Energy Reviews

149

View full text Add to dashboard Cite

show abstract

“…This scheme provides robustness against voltage unbalance. In [28], a notch filter is implemented inside the loop to improve the filtering characteristics. An adaptive low-pass notch filter-based PLL is presented in [19].…”

Section: Review Of Filtering Schemesmentioning

confidence: 99%

Rapid Tracking of Grid Variables Using Prefiltered Synchronous Reference Frame PLL

Chandrasekaran

Ragavan

2015

IEEE Trans. Instrum. Meas.

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For synchronization applications, synchronous reference frame (SRF) phase-locked loop (PLL) is widely deployed. Its performance is excellent when the input voltage consists of only fundamental positive sequence (FPS) component. If the grid voltage is unbalanced or polluted with harmonics and dc offset, its performance degrades. Many modifications were proposed to address this issue. However, the removal of dc offset and fundamental negative sequence (FNS) component without compromising the dynamic performance still remains a challenging task. To this end, this paper presents a rapid Type-1 SRF PLL scheme with preloop filtering stage for tracking the attributes of grid voltage FPS component. Fixed sampling period sliding discrete Fourier transform (SDFT) and instantaneous symmetrical components method are employed in the preloop stage. With this modification, the dc offset, harmonics and the FNS component are rejected and only the FPS component enters the PLL. As a result, transients vanish quickly. However, when the grid frequency drifts, SDFT causes amplitude and phase errors, and Type-1 PLL introduces a steady-state tracking error in phase. These errors are compensated with the help of an error correction criteria. Robustness and the improved transient response of the proposed scheme are demonstrated with an experimental study involving real-time controller board (dSPACE DS1104) and three-phase programmable power source.

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“…However, in Phipps et al (2006), a novel PLL design was proposed which, unlike traditional three-phase PLL, required no coordinate transformation. An optimized digital implementation of PLLs is presented in Freijedo et al (2011), where the digital oscillator is used to execute trigonometric functions. Jain et al (2014) focuses on optimizing the dynamic response of the PLL for fast tracking under disturbance.…”

Section: Introductionmentioning

confidence: 99%

Grid Synchronization Phase-Locked Loop Strategy for Unbalance and Harmonic Distortion Conditions

Chaoui

Okoye

Khayamy

2016

J Control Autom Electr Syst

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The synthesis, design and analysis of a threephase phase-locked loop (PLL) algorithm under grid voltage uncertainties is presented. Unlike other techniques, the proposed strategy is simple but yet, robust against unbalanced and distorted voltage conditions. The method does not rely on the symmetry of the three-phase voltages, like conventional PLL implementation techniques. Under phase lock, the reference voltage and the output voltage are in synchronism, hence they cross the zero axis at the same time. The proposed PLL implementation exploits this fact, by counting the difference between the zero crossing times of the grid voltage and the output voltage waveform, and generating an error signal proportional to this difference. This error is fed into a PI regulator which forces it to zero over time. The proposed algorithm is compared against two popular PLL techniques. Simulation and experimental results show better performance of the proposed PLL implementation in unbalanced grid voltage conditions.

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An Optimized Implementation of Phase Locked Loops for Grid Applications

Cited by 56 publications

References 24 publications

Three-phase phase-locked loop synchronization algorithms for grid-connected renewable energy systems: A review

Three-phase phase-locked loop synchronization algorithms for grid-connected renewable energy systems: A review

Rapid Tracking of Grid Variables Using Prefiltered Synchronous Reference Frame PLL

Grid Synchronization Phase-Locked Loop Strategy for Unbalance and Harmonic Distortion Conditions

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