A hybrid synchronous/fixed reference frame pll for phase synchronization with unbalanced three-phase grid conditions
Bibliographic record
Abstract
Control of power flow to or from the 3-phase grid requires accurate and fast estimation of both the positive sequence and the phase of the grid voltage, for proper timing of the power control devices. Unbalanced conditions will degrade the quality of this estimation. Following a Clarke transformation of the 3-phase to 2-phase αβ voltage signal, the positive sequence can be extracted by phase shifting the a and β signals by -90° and +90°, respectively. A hybrid scheme is proposed, embedding both a conventional two-phase PLL augmented with adaptive synchronous estimation of the positive sequence amplitude, and a generalized integrator to estimate the negative sequence. The two components are configured in parallel, according to the internal model principle, within a frequency adaptive, quadrature signal feedback structure. This results in faster response, and reduced signal processing complexity, making it suitable for DSP implementation in a wide range of applications. Parameter tuning is also simplified to suit application requirements. Experimental results are presented to validate the proposed method.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".