Cascaded PV Power Supply Layout for Lower Cable Current
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Solution Overview
Problem
Current photovoltaic power generation systems face challenges with high costs and losses due to large currents and cable diameters, leading to increased costs and inefficiencies in three-phase grid-connected inverters, particularly in centralized and decentralized architectures.
Innovation Solution
A power system design that cascades output voltages of power supplies and DC-to-AC units to reduce current flow, allowing for the use of lower wire diameter cables and reducing system costs, while also incorporating cascaded input and isolated output configurations to minimize power conversion device specifications and address potential induced degradation issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If centralized or decentralized inverter architectures are used with high conversion power, then conversion efficiency is improved, but input and output currents increase leading to larger cable diameters and higher costs
Solution Approach 1:
The patent segments the inverter system into multiple independent modular units, each handling a portion of the total power conversion. This segmentation allows each module to operate at optimized current levels, avoiding the need for large-diameter cables that would be required in a single centralized high-power inverter while maintaining overall high conversion efficiency.
2Adaptability or versatility
If distributed inverter architectures are used with low conversion power per unit, then system flexibility is improved, but input and output currents still increase leading to larger cable diameters and higher costs
Solution Approach 1:
The patent divides the distributed inverter system into segmented modular units with optimized power ratings. Each module maintains system flexibility while operating at current levels that allow the use of smaller-diameter cables, thus reducing material costs while preserving the adaptability benefits of distributed architecture.
3Power
If larger cable diameters are used to handle high currents, then current carrying capacity is improved, but system costs increase
Solution Approach 1:
By segmenting the power conversion into multiple modular units, the patent reduces the current that each cable must carry. This segmentation enables the use of smaller-diameter, lower-cost cables while maintaining the required total power transmission capacity, thus reducing overall system costs without compromising current carrying capability.
4Power
If larger cable diameters are used to handle high currents, then power transmission capability is improved, but power losses increase
Solution Approach 1:
The patent segments the power transmission path into multiple parallel paths through modular inverter units. This segmentation reduces the current in each individual cable, thereby reducing I²R losses in each cable. The cumulative effect across all modules achieves the required power transmission capability with lower total power losses compared to using a single high-current cable.
Data Source
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AI summary
Embodiments of this application provide a power system. Output terminals of a power supply or a DC-to-DC unit are cascaded to increase an output voltage, so as to reduce a current between the power supply or the DC-to-DC unit and the DC-to-AC unit, and resolve cost and loss problems of the cable from the power supply or the DC-to-DC unit to the DC-to-AC unit. In addition, according to the power system provided in the embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading output terminals of the power supply or the DC-to-DC unit and cascading inputs of the DC-to-AC unit, thereby reducing system costs. In addition, in the power system provided in the embodiments of this application, cascaded input and isolated output of the DC-to-AC unit can reduce a specification of a power conversion device. Therefore, problems of insufficient specifications and high costs of power conversion devices in the current industry are resolved. In addition, according to the power system provided in some embodiments, a problem of potential induced degradation (Potential Induced Degradation, PID) caused by a negative voltage of a battery panel to ground during operation of the system may be further resolved.