PV Backtracking Control for Uneven Terrain and Row Shading
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Solution Overview
Problem
Existing flat-ground backtracking algorithms for photovoltaic systems are inaccurate on uneven terrains, leading to shading between modules and a sharp drop in power generation, especially with series-parallel modules like half-cut photovoltaic modules.
Innovation Solution
A backtracking angle optimization method for series-parallel photovoltaic modules that adjusts tracking angles based on solar altitude and azimuth angles, using first and second optimization methods to minimize shading, ensuring optimal power generation on uneven terrains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If flat-ground backtracking algorithms are used, then the system is simple to implement, but the backtracking angle accuracy deteriorates on uneven terrains
Solution Approach 1:
The patent changes the input parameters from simple flat-ground assumptions to comprehensive terrain parameters including ground elevation data, module installation angles, and row spacing. This allows the algorithm to calculate accurate backtracking angles specifically adapted to uneven terrain conditions while maintaining reasonable computational complexity.
Solution Approach 2:
The patent segments the terrain into discrete measurement points along each row and uses these segmented data points to calculate backtracking angles. By dividing the continuous terrain into manageable segments, the algorithm achieves high accuracy on uneven ground without requiring overly complex continuous mathematical models.
2Object-affected harmful factors
If backtracking angle is increased to avoid shading, then shading between rows is reduced, but power generation efficiency deteriorates due to suboptimal solar tracking
Solution Approach 1:
The patent implements dynamic backtracking angle adjustment that varies continuously based on solar position, terrain characteristics, and row configuration. Rather than using fixed conservative angles, the system dynamically calculates optimal angles that minimize shading while maximizing energy capture throughout the day, resolving the trade-off between avoiding shading and maintaining tracking efficiency.
Solution Approach 2:
The system uses feedback from solar position data and terrain measurements to continuously optimize backtracking angles. By monitoring actual shading conditions and solar geometry, the algorithm adjusts angles in real-time to achieve the optimal balance between preventing inter-row shading and maintaining high power generation efficiency.
3Object-affected harmful factors
If conservative backtracking angles are used to prevent shading, then shading is minimized, but the backtracking performance deteriorates with loss of power generation
Solution Approach 1:
The patent applies local quality by considering specific local terrain conditions, module orientations, and row spacings to determine appropriate backtracking angles for each location. Rather than using uniform conservative angles across the entire system, the algorithm tailors angles to local conditions, minimizing shading where needed while preserving power generation where terrain and geometry allow.
Solution Approach 2:
The system applies partial backtracking action only when and where shading would occur, rather than consistently applying maximum backtracking angles. By using excessive action selectively - applying larger angles only when terrain and solar position require it - the system prevents shading problems while avoiding unnecessary loss of power generation efficiency during periods when shading is not an issue.
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AI summary
A backtracking angle optimization method (10), based on a series-parallel structure photovoltaic module, and a photovoltaic support control system applying same. The backtracking angle optimization method (10) is suitable for a photovoltaic system comprising multiple rows of series-parallel structure photovoltaic modules. When each row of photovoltaic modules is shielded in a manner not exceeding a first area, at least a portion of the photovoltaic modules outside of the first area may still operate at a normal power generation efficiency. The backtracking angle optimization method (10) comprises switching execution of a first optimization method and a second optimization method, the first optimization method comprising controlling each row of photovoltaic modules to shield at most a portion of the first area of the row of photovoltaic modules behind said row of photovoltaic modules, and the second optimization method comprising controlling such that there is no shielding between every two adjacent rows of photovoltaic modules.