Abstract
The second-order generalized integrator based orthogonal signal generator (SOGI-OSG) is commonly used to produce direct and quadrature axis ( dq-axes) signals in stationary reference frame for single-phase systems. Fast and robust OSG with harmonic rejection capability is required for parallel operation of power generation systems. The frequency response function (FRF) of classical OSG does not show robustness towards DC offset and grid harmonic disturbances compared to the direct signal of SOGI. This paper presents OSGs based on n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> order bandpass filter with a phase shifter using a scaled Q factor as a design variable. The frequency and time-domain performance analysis will be performed based on the scaled Q factor to simplify the design process of the proposed OSGs. The -3dB frequency and settling step time will be matched in higher order OSGs selecting a scaled Q factor. The proposed method will show enhanced harmonic rejection ratio of an additional -20dB with increasing OSG order with tradeoff in computational burden.
Highlights
Phase-locked loop (PLL) is required in a wide variety of AC applications including single-phase system control
The paper is organized as follows: Section II compares harmonic rejection ability of Second-order generalized integrator (SOGI)-based Orthogonal Signal Generator (OSG) and the proposed OSGs, summarizing the tradeoff between filtering ability and computational burden; in section III, the proposed OSGs based on nth-order bandpass filter (BPF) with scaled Q factor is introduced with time- and frequency-domain analysis; section IV shows the implementation of the PLL using the proposed OSGs; section V, shows the simulation and experimental results to demonstrate the advantages of the proposed OSG; section VI presents the conclusions of the paper
It has been shown that SOGI-PLL has weakness in the low harmonic rejection capability
Summary
Phase-locked loop (PLL) is required in a wide variety of AC applications including single-phase system control. The modified SOGI (MSOGI-PLL) with an additional filter block is proposed to remove the DC offset component causing constant error [17] These techniques, showed asymmetric harmonic rejection capability on the low and high-frequency range. Both time-domain and frequency-domain analysis are performed for the second- and the third-order OSGs. The proposed OSGs are adopted to fixed-frequency OSG-PLL in Fig. 1 (b) introducing lookup table (LUT) based phase compensator to adapt input frequency drift. The paper is organized as follows: Section II compares harmonic rejection ability of SOGI-based OSGs and the proposed OSGs, summarizing the tradeoff between filtering ability and computational burden; in section III, the proposed OSGs based on nth-order BPF with scaled Q factor is introduced with time- and frequency-domain analysis; section IV shows the implementation of the PLL using the proposed OSGs; section V, shows the simulation and experimental results to demonstrate the advantages of the proposed OSG; section VI presents the conclusions of the paper
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
