Interleaved PV Substrings for Partial Shading Mismatch Mitigation

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Solution Overview

Problem

Current photovoltaic (PV) modules face inefficiencies due to mismatch conditions caused by partial shading, where reduced irradiation in some cells leads to reduced output and potential damage from 'hot-spots' in the entire string, as healthy cells become forward biased and shaded cells reverse biased.

Innovation Solution

The solution involves static reconfiguration of PV cell arrays with substrings connected in parallel, series-parallel, or cross-tied configurations, utilizing conductive backsheets and rear contact PV cells to mitigate mismatch conditions and improve efficiency, allowing for easier manufacturing and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If PV cells are connected in series to provide useful electric potential and current output, then the power output is improved, but the system becomes vulnerable to mismatch conditions and hot-spot damage when partial shading occurs

Engineering Contradiction:
Improvepower outputVSAvoidreliability under partial shading
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The PV module is divided into multiple substrings, each containing series-connected PV cells. These substrings are then connected in parallel to each other, creating a segmented structure that isolates the impact of partial shading to individual substrings rather than affecting the entire module. This segmentation allows healthy substrings to continue producing power at full capacity while shaded substrings operate at reduced capacity without causing hot-spot damage to other substrings.

Inventive Principle:
Principle #1Segmentation

2Power

If multiple PV cells are connected serially in a string, then useful electric potential is generated, but the entire string's production is reduced when one or more cells experience reduced irradiation

Engineering Contradiction:
Improveelectric potentialVSAvoidenergy production
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

Multiple substrings, each generating electric potential through series-connected cells, are merged by connecting them in parallel. This merging combines the voltage output of individual substrings while allowing each substring to operate independently in terms of current generation. The parallel connection ensures that the total power output is the sum of individual substring outputs, preventing the bottleneck effect that occurs in purely series connections when one cell is shaded.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If substrings are arranged in parallel configurations, then mismatch condition mitigation is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvemismatch condition mitigationVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs universal interconnection methods and standardized substring designs that can be applied across different PV module configurations. The same parallel connection topology and substrate structures are used regardless of the specific number of substrings or cells, allowing for scalable manufacturing. This universality simplifies the manufacturing process by reducing the need for custom designs for different module sizes and configurations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 configuration enhances PV module efficiency by distributing the effects of reduced irradiation, reducing the occurrence of 'hot-spots', and minimizing manufacturing complexity, thereby improving overall energy production and module reliability.

Implementation Method 1

photovoltaic (PV) electrical energy

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4489081A1Arrangements of substrings in photovoltaic modules
Publication Date: 2025.01.08 SOLAREDGE TECH LTD
  • EP4489081A1 patent drawingFigure 1A~1B
  • EP4489081A1 patent drawingFigure 2A~2B
  • EP4489081A1 patent drawingFigure 3A~3B

AI summary

Aspects of the disclosure relate to static configurations and arrangement of substrings of photovoltaic (PV) cell arrays or PV modules to electrically parallelly connect substrings in PV cell arrays mitigating the partial shade and/or mismatch condition. Further aspects relate to PV modules comprising interleaved substrings. Additional aspects relate to incorporation of power electronics with PV modules and PV cell arrays.