Journal ArticleDOI
Single-phase phase locked loop with dc offset and noise rejection for photovoltaic inverters
Reads0
Chats0
TLDR
In this article, an improved phase-locked loop (PLL) structure with capability to fully reject DC offset and noise which could appear in measured input grid voltage has been proposed, which can solve important issues of presence of noise and DC offset in measured grid voltage.Abstract:
Proper work of grid-connected converters requires an accurate detection of phase angle, frequency and amplitude of grid voltage. Phase locked loops (PLLs) based on synchronous reference frame theory can be used for estimation of these grid parameters. One of the issues that could appear during estimation of grid parameters is appearance of DC offset in measured grid voltage. This DC component (offset) is usually entered in PLL structure via measurement and A/D conversion process. Undesirable induced DC offset could appear as part of the reference sine current of photovoltaic inverters or other grid-connected converters. A lot of standards define allowed PV inverter's DC current injection in the grid. In this study, we propose an improved PLL structure with capability to fully reject DC offset and noise which could appear in measured input grid voltage. The key component of the proposed PLL is two-phase generator with a closed control loop for DC offset and noise rejection. Obtained simulation and experimental results show that the proposed PLL structure can solve important issues of presence of noise and DC offset in measured grid voltage. The proposed PLL structure shows excellent dynamical performances in conditions of fast changes of grid parameters.read more
Citations
More filters
Journal ArticleDOI
Five Approaches to Deal With Problem of DC Offset in Phase-Locked Loop Algorithms: Design Considerations and Performance Evaluations
TL;DR: Several approaches using the dq-frame delayed signal cancellation operator and the notch filter as the PLL in-loop filtering stages and using the αβ-frame DSC operator, the complex coefficient filter, and a cross-feedback network for blocking the dc offset before the P LL input are analyzed.
Journal ArticleDOI
DC Offset Rejection Improvement in Single-Phase SOGI-PLL Algorithms: Methods Review and Experimental Evaluation
TL;DR: A comprehensive analysis and performance evaluation of several advanced second-order generalized integrator (SOGI)-based PLL methods in enhancing the dc offset rejection capability for single-phase grid-connected power converters is presented.
Journal ArticleDOI
A Critical Examination of Frequency-Fixed Second-Order Generalized Integrator-Based Phase-Locked Loops
TL;DR: The main aim of this letter is to provide a critical analysis of frequency-fixed SOGI-based PLLs to highlight their real advantages and disadvantages.
Journal ArticleDOI
DC-Offset Rejection in Phase-Locked Loops: A Novel Approach
TL;DR: A novel method to tackle the presence of dc offset in PLLs is presented, which causes fundamental-frequency oscillatory errors in their estimated quantities.
Journal ArticleDOI
Analysis and design of notch filter-based PLLs for grid-connected applications
TL;DR: In this paper, a hybrid combination of adaptive/nonadaptive notch filters (NNF-PLLs) is proposed to deal with the interference caused by the presence of harmonics in the PLL input.
References
More filters
Journal ArticleDOI
Operation of a phase locked loop system under distorted utility conditions
TL;DR: In this article, a phase-locked loop (PLL) system under distorted utility conditions is presented and a control model of the PLL system is developed and recommendations are made on tuning of this model specially for operation under common utility distortions such as line notching, voltage unbalance/loss, and frequency variations.
Proceedings ArticleDOI
A New Single-Phase PLL Structure Based on Second Order Generalized Integrator
TL;DR: In this article, a phase-locked-loop (PLL) method for single-phase systems was proposed to detect the phase angle, amplitude and frequency of the utility voltage.
Proceedings ArticleDOI
Stationary-frame generalized integrators for current control of active power filters with zero steady-state error for current harmonics of concern under unbalanced and distorted operating conditions
TL;DR: In this paper, the authors proposed several concepts of integrators for sinusoidal signals, including parallel and series associations of the basic PI units using the stationary frame generalized integrators, for current control of active power filters.
Proceedings ArticleDOI
PLL structures for utility connected systems
TL;DR: In this paper, a detailed analysis of phase-locked loop structures for utility connected systems is presented, and a single-phase PLL structure derived from the three-phase topology is discussed and its behavior under distorted utility conditions is analyzed.
Journal ArticleDOI
Phase-locked loop for grid-connected three-phase power conversion systems
TL;DR: In this article, a phase-locked loop (PLL) is proposed for the power factor control of grid-connected three-phase power conversion systems, and the performance of the PLL is analyzed under distorted utility conditions such as the phase unbalancing harmonics, and offset caused by nonlinear loads and measurement errors.