公开(公告)号：US20210273602A1

公开(公告)日：2021-09-02

申请号：US16805798

申请日：2020-03-01

Applicant: NEXTracker Inc.

Inventor： Fei Gu ,  Yang Liu ,  Venkata Rahul Abbaraju ,  Eric Martinez

IPC: H02S20/32 ,  G05D3/10

Abstract: Split-cell and multi-panel photovoltaic backtracking control systems and methods allow for increased total power generation during low sun elevation conditions by shading a percentage of panel modules, thereby allowing for a lower angle of incidence on unshaded modules. The control systems and methods involve determining a sun elevation angle, a traditional backtracking angle, a split-cell or multi-panel backtracking angle, a single-cell or single-panel relative light transmission (RLT) based on the single-cell or single-panel backtracking angle, and a split-cell or multi-panel RLT based on the split-cell or multi-panel backtracking angle. If twice the single-cell or single-panel RLT is greater than the split-cell or multi-panel RLT, the split-cell or multi-panel backtracking angle is used; otherwise, the single-cell or single-panel backtracking angle is used. The control systems and methods may further involve determining a diffuse fraction index (DFI) and, if the DFI is greater than a DFI limit, using a DFI tracking angle.

公开(公告)号：US20220147091A1

公开(公告)日：2022-05-12

申请号：US17601921

申请日：2020-05-04

Applicant: NEXTracker Inc.

Inventor： Yang Liu ,  Alexander W. AU ,  Fei Gu

IPC: G05F1/67 ,  H02J3/38 ,  H02J7/35

Abstract: Solar power systems and methods utilize DC power transmission and centralized power inversion. The solar power systems include a photovoltaic (PV) bus system and a fixed bus system. The PV system utilizes a control mode handoff control method, which includes determining that a local maximum power point tracking (MPPT) control is enabled; in response to determining that the local MPPT control is enabled, starting an MPPT mode timer; performing local MPPT; determining that the MPPT mode timer is greater than a predetermined period; and, in response to determining that the MPPT mode timer is greater than a predetermined period, handing off MPPT control to the next MPPT controller. The distributed MPPT control method may include sequential MPPT control, adaptive ΔV MPPT control, and/or power limiting control. The fixed bus system includes PV string-level MPPT controllers and a fixed DC input central inverter or multiple fixed DC modular inverters.