Local String Management Unit for Solar Array Voltage Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional maximum power point tracking (MPPT) algorithms in photovoltaic systems fail to optimize energy production when solar modules within a solar array operate at different working points due to installation, fabrication, or degradation differences, leading to reduced overall energy output.
Innovation Solution
Implementing a system with local management units (LMUs) that connect solar modules in series and parallel, allowing for voltage conversion and bypass modes to balance string outputs, enabling the selection of a target voltage and adjusting string voltages to maximize energy production by isolating weak modules and optimizing current and voltage distribution across the array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional MPPT algorithm treats solar array as single module, then system complexity is reduced, but energy production optimization deteriorates
Solution Approach 1:
The solar array is segmented into multiple strings, with each string managed by a dedicated LSMU that independently tracks the maximum power point for that specific string. This segmentation allows each string to be optimized separately based on its individual performance characteristics, resolving the contradiction by maintaining low system complexity through modular design while significantly improving energy production through targeted optimization of each segment.
2Adaptability or versatility
If solar modules operate at different working points, then individual module performance is optimized, but overall array output deteriorates
Solution Approach 1:
Each string is assigned a local management unit that applies tailored control strategies specific to that string's characteristics, including its operating point, module conditions, and performance level. Strong strings receive different management than weak strings, with LSMUs dynamically adjusting operating parameters to balance overall array output while respecting individual string capabilities, thus achieving both local optimization and global productivity improvement.
3Productivity
If weak modules are isolated through bypass modes, then strong modules can operate at full capacity, but device complexity increases
Solution Approach 1:
The LSMU acts as an intermediary between the solar string and the parallel bus, providing intelligent routing that directs current from strong strings to the bus while bypassing weak modules through dedicated bypass switches. This intermediary approach enables strong modules to operate at full capacity without being constrained by weak modules, while the bypass mechanism remains integrated within the modular LSMU architecture, preventing excessive complexity increase.
Data Source
AI summary
Apparatuses and methods include a solar array having one or more strings of series-connected local management units (LMUs). Each LMU is parallel-connected to one of a plurality of solar modules. The strings are connected in parallel via a parallel bus. Local string management units (LSMUs) can increase or decrease an output voltage of the solar array by upconverting or downconverting string output voltages from each string. LSMUs can also operate in a bypass mode to increase overall power output.