Photovoltaic String MPPT Algorithm for Absolute Maximum Power Point
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Solution Overview
Problem
Current Maximum Power Point Tracking (MPPT) algorithms for photovoltaic panels are inefficient in identifying the absolute point of maximum power delivery when there are variations in panel conditions, such as shading or malfunction, leading to suboptimal energy production and increased need for management devices.
Innovation Solution
A method that cyclically adjusts the voltage of a string of photovoltaic panels to observe power variations, using perturbation steps and voltage reductions to identify and lock onto the absolute maximum power point, optimizing power delivery even in conditions with multiple local maxima.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the Perturb and Observe MPPT algorithm is used to track maximum power point, then the algorithm is simple to implement, but it cannot identify the absolute maximum power point when multiple local maxima exist due to panel variations or shading
Solution Approach 1:
The algorithm dynamically adjusts the voltage perturbation step size based on the observed power change. When a significant power increase is detected, the algorithm increases the step size to quickly traverse through local maxima and reach higher power regions. When power decreases, it reduces the step size to avoid overshooting the absolute maximum power point. This dynamic adaptation allows the algorithm to efficiently navigate complex power-voltage curves with multiple local maxima while maintaining implementation simplicity.
Solution Approach 2:
The invention changes the perturbation parameter (voltage step size) from a fixed predetermined value to a variable that adapts based on system conditions. The algorithm monitors the relationship between voltage changes and power output, then adjusts the perturbation magnitude accordingly. This parameter transformation enables the system to distinguish between local and absolute maximum power points by observing how power responds to different perturbation levels, thereby resolving the contradiction between simplicity and accuracy.
2Stability of the object's composition
If small voltage perturbation steps are used to maintain operation near the current maximum power point, then the panel operates stably, but the algorithm cannot escape local maxima to find the absolute maximum power point
Solution Approach 1:
The algorithm implements dynamic step size adjustment where the perturbation magnitude is no longer fixed but varies based on the system's response to previous perturbations. When the algorithm detects that small steps are keeping it trapped in a local maximum (by observing insufficient power increases), it automatically increases the step size to enable larger voltage jumps that can escape local maxima. This dynamic behavior maintains stability during normal operation while enabling productivity improvement when local maxima are detected.
Solution Approach 2:
The algorithm periodically evaluates whether the current operating point is a local or absolute maximum by applying test perturbations and observing the power response. This periodic assessment mechanism allows the system to switch between exploration mode (larger perturbations to find better points) and exploitation mode (smaller perturbations to maintain operation near the optimum). The periodic nature of this evaluation ensures that the system can escape local maxima when conditions warrant while maintaining stability during sustained optimal operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method ensures maximum power delivery efficiency by identifying the absolute maximum power point, reducing the number of management devices required and maintaining high efficiency across varying conditions, including shading and malfunctions.
Implementation Method 1
photovoltaic cells and photovoltaic panels, each of which comprises a plurality of such cells, are used to generate electricity from solar radiation
Data Source
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AI summary
A method for determining the absolute point of maximum power delivered by a string (1) of photovoltaic panels (100) connected together in series. The method foresees that the sequence of operations (A) be carried out cyclically for every time interval ΔΤ2, repeated a maximum number of times M, which foresees that the voltage value Vi set for the string (1) be decreased by a voltage quantity ΔV2 of value substantially equal to the open circuit nominal voltage value of each of said photovoltaic panels (100) belonging to said string (1), observing the value of the power delivered Pvi - ΔV2 at the voltage value Vi - ΔV2, and, in the case in which the power value PVi - ΔV2 is greater than the value of the power PVi delivered at the set voltage value Vi, setting as voltage value Vi on the string (1) of photovoltaic panels (100) the voltage value Vi decreased by the quantity ΔV2.