PV Wiring Module Switch Layout for Reverse Fault Isolation
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Solution Overview
Problem
Conventional photovoltaic systems fail to effectively isolate short-circuit currents after a direct-current switch is opened, leading to safety hazards such as fires due to arc faults when reverse connection faults occur.
Innovation Solution
A wiring module with a first and second switch configuration, where each switch connects to a specific number of photovoltaic strings, ensuring that positive and negative electrodes of different strings are not connected in parallel, thereby preventing short-circuit currents by isolating faulty connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple photovoltaic strings are connected to the same direct-current switch, then the device complexity is reduced, but short-circuit current cannot be effectively isolated when reverse connection faults occur
Solution Approach 1:
The patent divides the connection relationship between photovoltaic strings and switches into independent segments. Each photovoltaic string is assigned to a unique combination of first switch and second switch, creating segmented connection paths that prevent short-circuit current propagation between different strings when faults occur.
Solution Approach 2:
The patent introduces an intermediary control mechanism that monitors the connection status between photovoltaic strings and switches. When a reverse connection fault is detected, the control system activates the appropriate switches to isolate the faulty string, preventing short-circuit current from affecting other strings while maintaining normal operation of healthy connections.
2Ease of operation
If direct-current switches are manually controlled to break connections, then the control simplicity is improved, but safety hazards such as fire due to arc faults still exist
Solution Approach 1:
The patent implements preliminary detection and control actions by continuously monitoring the connection status of photovoltaic strings before faults can develop into dangerous conditions. When reverse connection is detected, the system proactively opens the appropriate switches to isolate the faulty string, preventing arc faults and fire hazards before they can occur.
Solution Approach 2:
The patent establishes a feedback control system that continuously monitors the electrical parameters of photovoltaic strings and switch states. When abnormal conditions indicating reverse connection are detected, the system provides feedback signals to open the appropriate switches, creating a closed-loop control mechanism that prevents safety hazards while maintaining simple operational control.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
Provided in the present application are a wiring module, a combiner box and a converter. In the wiring module, one side of a first switch thereof serves as an input terminal positive pole and is connected to a positive electrode of at least one direct-current power supply, and one side of a second switch thereof serves as an input terminal negative pole and is connected to a negative electrode of at least one direct-current power supply. In addition, there is less than or equal to one direct-current power supply to which any input terminal positive pole is connected and to which any input terminal negative pole is also connected, that is, no parallel connection relationship is present between different direct-current power supplies. Therefore, in the event of a reverse connection fault in a direct-current power supply, as long as a switch connected to same is disconnected, a short-circuit current between the reversely-connected direct-current power supply and any properly-connected direct-current power supply can be avoided, thereby effectively achieving fault isolation.