Phase locked-loop with decaying DC transient removal for three-phase grids. (December 2022)
- Record Type:
- Journal Article
- Title:
- Phase locked-loop with decaying DC transient removal for three-phase grids. (December 2022)
- Main Title:
- Phase locked-loop with decaying DC transient removal for three-phase grids
- Authors:
- Liu, Xiaokang
Xiong, Liansong
Wu, Binbing
Qian, Yang
Liu, Yonghui - Abstract:
- Abstract: Frequency and phase of the power grid, which are critical for reliable control and protection of grid-tied devices, are generally detected by the closed-loop phase locked-loop (PLL). In highly inductive high-voltage transmission systems, decaying DC (DDC) components with large amplitude can be easily introduced by load disturbances and/or grid abnormalities, leading to severe performance degradation of the PLL during the transient. Focusing on this issue, in this paper, modifications to the conventional synchronous reference frame (SRF)-PLL have been made to address the short-term disturbances including the DDC component, and the system operation is divided into the normal state and the DDC-transient state. The SRF-PLL is only adopted for the normal state where the DDC component is negligible. In the presence of a significant DDC component, as well as disturbances including negative-/zero-sequence components and harmonics, the weak effectiveness of the conventional SRF-PLL is proved, and an efficient DDC component extraction method, with a detection time of 0.5 grid cycle, is introduced for the three-phase system. The real-time amplitude and phase of the positive-sequence component can be efficiently extracted via the proposed scheme, by exploiting the transient signal properties in the dq -frame and assuming a constant grid frequency during the short transient. Finally, a proper design of switching logic has been proposed to allow for the fast and preciseAbstract: Frequency and phase of the power grid, which are critical for reliable control and protection of grid-tied devices, are generally detected by the closed-loop phase locked-loop (PLL). In highly inductive high-voltage transmission systems, decaying DC (DDC) components with large amplitude can be easily introduced by load disturbances and/or grid abnormalities, leading to severe performance degradation of the PLL during the transient. Focusing on this issue, in this paper, modifications to the conventional synchronous reference frame (SRF)-PLL have been made to address the short-term disturbances including the DDC component, and the system operation is divided into the normal state and the DDC-transient state. The SRF-PLL is only adopted for the normal state where the DDC component is negligible. In the presence of a significant DDC component, as well as disturbances including negative-/zero-sequence components and harmonics, the weak effectiveness of the conventional SRF-PLL is proved, and an efficient DDC component extraction method, with a detection time of 0.5 grid cycle, is introduced for the three-phase system. The real-time amplitude and phase of the positive-sequence component can be efficiently extracted via the proposed scheme, by exploiting the transient signal properties in the dq -frame and assuming a constant grid frequency during the short transient. Finally, a proper design of switching logic has been proposed to allow for the fast and precise transition between the normal and the DDC-transient state, thereby ensuring high steady-state accuracy as well as short-term DDC transient immunity. Hardware-in-the-loop based experiments have been used to verify the effectiveness of the proposed PLL technique. Highlights: Decaying DC (DDC) components lower performance of traditional closed-loop phase locked-loop (PLL). Proposed PLL scheme efficiently detects grid phase in presence of DDC components. DDC transient criterion is designed based on positive-sequence signal and SNR. Proper measures increase phase detection speed/accuracy at transient start/end. … (more)
- Is Part Of:
- International journal of electrical power & energy systems. Volume 143(2022)
- Journal:
- International journal of electrical power & energy systems
- Issue:
- Volume 143(2022)
- Issue Display:
- Volume 143, Issue 2022 (2022)
- Year:
- 2022
- Volume:
- 143
- Issue:
- 2022
- Issue Sort Value:
- 2022-0143-2022-0000
- Page Start:
- Page End:
- Publication Date:
- 2022-12
- Subjects:
- Decaying DC component -- Phase locked-loop -- Transient signal -- Unbalanced grid -- Harmonics
Electrical engineering -- Periodicals
Electric power systems -- Periodicals
Électrotechnique -- Périodiques
Réseaux électriques (Énergie) -- Périodiques
Electric power systems
Electrical engineering
Periodicals
621.3 - Journal URLs:
- http://www.sciencedirect.com/science/journal/01420615 ↗
http://www.elsevier.com/journals ↗ - DOI:
- 10.1016/j.ijepes.2022.108508 ↗
- Languages:
- English
- ISSNs:
- 0142-0615
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - 4542.220000
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