AC Module Plug-and-Play Grounding for Simplified PV Installation
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Solution Overview
Problem
Existing photovoltaic (PV) systems require complex and labor-intensive installation methods for intra-module dc grounding, involving metallic splices, screws, lugs, and wires, which are time-consuming and require experienced electricians, especially for systems with micro-inverters and metallic frames.
Innovation Solution
The implementation of plug and play ac-voltage connectors with a built-in grounding pin that automatically grounds module frames through a low resistance path, eliminating the need for physical grounding wires or clips by integrating the grounding pin into the ac cable and connector system, allowing modules to be easily interconnected and grounded during installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional grounding methods using heavy gauge copper wire, screws, and washers are used to ground each module frame, then reliable electrical contact and grounding continuity are achieved, but installation complexity and labor time increase substantially
Solution Approach 1:
The patent combines multiple grounding components (wire, screw, washer) into a single integrated grounding clip assembly. The clip includes a gripping portion that mechanically attaches to the module frame and an conductive portion that provides electrical connection, eliminating the need for separate components and reducing installation steps while maintaining reliable grounding continuity.
Solution Approach 2:
The grounding clip is designed to be self-installing through a simple snap-in or clip-on mechanism that requires no special tools or complex procedures. The gripping portion automatically secures to the module frame structure, and the conductive portion automatically establishes electrical contact, enabling installers to ground modules quickly without requiring experienced electricians.
2Reliability
If heavy gauge copper wire and penetrating washers are used to ensure reliable electrical contact on anodized frames, then grounding reliability is improved, but installation time and labor requirements increase
Solution Approach 1:
The grounding clip integrates the mechanical attachment function and electrical conduction function into a single component. The gripping portion provides secure mechanical attachment to the module frame while the conductive portion simultaneously establishes reliable electrical contact, eliminating the need for separate wire and washer components and reducing installation time.
Solution Approach 2:
The grounding clip uses a spring-loaded or flexible conductive portion that can deform to conform to the anodized frame surface, ensuring reliable electrical contact without requiring penetrating washers that cut into the frame. This changes the contact mechanism from mechanical penetration to elastic deformation, maintaining reliability while reducing installation complexity.
3Reliability
If experienced electricians are required to make hands-in grounding connections, then grounding reliability is ensured, but installation cost and complexity increase
Solution Approach 1:
The grounding clip is designed as a self-installing component that requires no special skills or tools. The clip simply snaps onto or clips onto the module frame, with the conductive portion automatically making electrical contact. This self-service design allows any installer to perform grounding connections reliably without requiring experienced electricians, reducing both cost and complexity.
Solution Approach 2:
The grounding clip acts as an intermediary device that simplifies the grounding connection process. Instead of requiring direct manipulation of wire and fasteners, the clip provides a pre-assembled intermediate component that bridges the module frame to the grounding system through a simple mechanical attachment, making the process accessible to less experienced installers.
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 solution simplifies the installation process by enabling safe and reliable grounding of PV ac-modules without the need for additional grounding components, reducing installation time and costs while ensuring compliance with electrical codes, and allowing for easier expansion or replacement of modules.
Implementation Method 1
a dc ground conductor (60) electrically connected internal to its corresponding micro-inverter (32) to a corresponding micro-inverter chassis/ground (36)
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A photovoltaic (PV) ac-module grounding system includes a plurality of PV dc-voltage modules (34). Each PV dc-voltage module (34) is integrated with a corresponding dc-ac micro-inverter (32) to provide a corresponding PV ac-voltage module (38). Each PV ac-voltage module (38) includes an ac-voltage plug and play connector (42) (43) that includes a dc ground conductor. Each dc-ac micro-inverter (32) is internally electrically connected to its own chassis ground or metal enclosure (36) which in turn is electrically connected to a corresponding dc ground conductor (60). A dc ground path (60) is carried through an ac power bus from ac-voltage module (38) to ac-voltage module (38) through the plug and play connectors (42) (43) via the dc ground conductors (60).