PV Module Disconnection Switching for Emergency Safety

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Emergency personnel are at risk of electrical hazards when responding to solar energy generation systems, as the conductor string on the source side of an inverter may remain energized even after the power is disconnected from the load, posing a danger due to potentially high voltages.

Innovation Solution

A method and apparatus for electrically connecting and disconnecting photovoltaic modules from a distribution system, utilizing switching devices and a control message transmitter to monitor conditions and automatically or manually disconnect the modules during emergencies, ensuring safety by reducing voltage and isolating the modules from the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the inverter disconnects the load during an emergency, then the power to the load is cut off, but the conductor string on the source side remains energized creating a safety hazard

Engineering Contradiction:

Improvesafety of emergency personnelVSAvoidelectrical hazard from energized conductor string

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system divides the conductor string into separable segments using switching devices. Each switching device can isolate specific portions of the conductor string from the photovoltaic modules, allowing the inverter to disconnect the load while also providing the capability to disconnect the source side conductors to eliminate electrical hazards for emergency personnel.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Switching devices are introduced as intermediary components between the photovoltaic modules and the inverter. These intermediaries can be controlled to open or close circuit paths, enabling safe disconnection of the conductor string from the source side while maintaining system functionality during normal operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If switching devices are added to disconnect the conductor string, then safety for emergency personnel is improved, but device complexity increases

Engineering Contradiction:

Improvesafety of emergency personnelVSAvoidnumber of switching devices and control systems

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The switching devices are designed to perform multiple functions: normal system operation, emergency load disconnection, and source side conductor isolation. By making these components multi-functional, the patent reduces the need for separate dedicated devices for each function, thereby limiting the increase in overall system complexity while still achieving enhanced safety.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control system automatically manages the switching devices based on system conditions and emergency signals. This self-service capability reduces the need for manual intervention and simplifies the control architecture, as the system autonomously determines when and how to isolate conductors without requiring complex external control mechanisms.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS9991717B1Method and apparatus for connecting and disconnecting a photovoltaic module to a distribution system

Publication Date: 2018.06.05 ROCO LLC

AI summary

A method and apparatus for electrically connecting and disconnecting a photovoltaic (PV) module from a distribution system includes determining whether one or more conditions are met to connect the PV module to the distribution system. The PV module is connected to the distribution system based upon the determination of whether the one or more conditions are met, and the one or more conditions are monitored. The PV module is disconnected from the distribution system if one or more of the conditions are not met.