Abstract
The phase-locked loop (PLL) is the main controller element for the fast and accurate synchronisation and operation of grid-connected renewable energy systems (RESs). It is used to extract the grid voltage information such as the phase angle, the frequency and amplitude. Subsequently, this information is used in the control system of the grid-side converter of the RES. The performance of the PLL is critical under abnormal grid conditions such as in the event of balanced and/or unbalanced faults, frequency and phase variations, the presence of harmonics, interharmonics and DC offset. This study sets out with a benchmarking study of the four latest state-of-the-art PLLs. The PLLs compared are the decoupled dual synchronous reference frame PLL, the decoupling network designed in αβ-frame PLL, the enhanced pre-filtering moving average filter type-2 PLL and the harmonic-interharmonic DC-offset PLL. The PLLs are analysed and compared based on their performance, their dynamic response and their computational complexity. The benchmarking concludes with a PLL selection guide depending on the application and other system constraints. Experiments and simulation results are presented to compare and analyse the performance of the selected PLLs.
Original language | English |
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Pages (from-to) | 52-62 |
Number of pages | 11 |
Journal | IET Renewable Power Generation |
Volume | 14 |
Issue number | 1 |
Early online date | 19 Dec 2019 |
DOIs | |
Publication status | Published - 6 Jan 2020 |
Externally published | Yes |
Keywords
- synchronisation
- renewable energy sources
- dynamic response
- power grids
- phase locked loops
- power system harmonics
- power convertors
- performance evaluation
- PLL algorithms
- grid-connected RES applications
- phase-locked loop
- main controller element
- accurate synchronisation
- grid-connected renewable energy systems
- grid voltage information
- phase angle
- control system
- grid-side converter
- abnormal grid conditions
- balanced faults
- unbalanced faults
- phase variations
- benchmarking study
- decoupled dual synchronous reference frame PLL
- decoupling network
- PLL selection guide
- system constraints
- harmonic-interharmonic DC-offset PLL
- enhanced prefiltering moving average filter type-2 PLL