Distributed DC Power System for Mismatched Solar Panel Arrays
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Solution Overview
Problem
Conventional solar panel arrays face inefficiencies due to mismatched solar panels, which lead to suboptimal power output and increased costs, as they require precise matching and installation conditions to achieve maximum power points, and are prone to hot spots and low power utilization.
Innovation Solution
A distributed power system with multiple DC batteries and power converters, each with a control loop to set voltage or current, allowing for serial and parallel connections of mismatched solar panels, enabling independent maximum power point tracking for each panel and reducing conduction losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If solar panels are connected in series to achieve required operating voltage, then voltage requirement is met, but current capability is insufficient
Solution Approach 1:
The system divides the solar panel array into multiple independent strings, each with its own power converter. This segmentation allows each string to operate independently at its optimal current level while contributing to the total system voltage, resolving the contradiction between voltage requirements and current capability.
Solution Approach 2:
The patent introduces a new dimensional approach by adding independent power converters for each string, transforming the system from a single-dimensional series connection to a multi-dimensional architecture where voltage and current can be independently optimized across different strings.
2Power
If multiple strings are connected in parallel to provide required current, then current requirement is met, but system complexity increases
Solution Approach 1:
Each string is equipped with its own dedicated power converter, creating modular independent units. This segmentation simplifies the overall system architecture by allowing each module to be designed, installed, and maintained independently, reducing the complexity burden of parallel connections.
Solution Approach 2:
The patent applies local quality by giving each string its own power converter with independent control capabilities. This allows each local unit to be optimized for its specific conditions while contributing to the overall system, making the complex parallel configuration more manageable.
3Productivity
If solar panels are precisely matched and installed under specific conditions to achieve maximum power points, then power output efficiency is improved, but installation requirements and costs increase
Solution Approach 1:
The power converters perform automatic maximum power point tracking (MPPT) for each string independently, allowing the system to self-optimize its performance without requiring precise manual matching of panels or complex installation conditions. The system serves itself by continuously adapting to varying conditions.
Solution Approach 2:
The patent dynamically changes operating parameters through independent power converter control, allowing each string to operate at its optimal power point regardless of panel variations or installation conditions. This eliminates the need for precise initial matching by enabling continuous parameter optimization.
4Power
If conventional series-parallel connections are used for solar panels, then voltage and current requirements are met, but mismatched panels cause hot spots and reduced power utilization
Solution Approach 1:
By dividing the system into independently controlled strings with dedicated power converters, the patent isolates mismatched panels to their respective strings. This prevents mismatch-induced hot spots from affecting the entire array, as each string operates independently at its optimal current level.
Solution Approach 2:
The patent applies local quality control by enabling independent maximum power point tracking for each string. This allows each local unit to optimize its power extraction based on its specific panel characteristics, preventing the propagation of mismatch effects across the entire system and reducing hot spot formation.
Data Source
AI summary
A distributed power system including multiple (DC) batteries each DC battery with positive and negative poles. Multiple power converters are coupled respectively to the DC batteries. Each power converter includes a first terminal, a second terminal, a third terminal and a fourth terminal. The first terminal is adapted for coupling to the positive pole. The second terminal is adapted for coupling to the negative pole. The power converter includes: (i) a control loop adapted for setting the voltage between or current through the first and second terminals, and (ii) a power conversion portion adapted to selectively either: convert power from said first and second terminals to said third and fourth terminals to discharge the battery connected thereto, or to convert power from the third and fourth terminals to the first and second terminals to charge the battery connected thereto. Each of the power converters is adapted for serial connection to at least one other power converter by connecting respectively the third and fourth terminals, thereby forming a serial string. A power controller is adapted for coupling to the serial string. The power controller includes a control part adapted to maintain current through or voltage across the serial string at a predetermined value.