Solar Module Pressure-Actuated Switching Contact Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solar modules face issues with hazardous touch voltages during assembly, maintenance, or in case of malfunction or fire, as they maintain open-circuit voltage at current connections, and existing solutions either diminish current or lack effective protection against touch voltages.
Innovation Solution
A solar module with a mechanical switching contact in parallel to serially connected solar cells, actuated by a pressure-sensitive mechanism that short-circuits the cells when control pressure is absent, ensuring the module is voltage-free and protected against touch voltages, and can be easily connected to additional modules via a control pressure line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bypass diode is used to protect against touch voltages, then the solar module is protected during shading or malfunction, but the current supplied by the solar module is diminished by the current consumed by control electronics
Solution Approach 1:
The patent extracts the control electronics from the solar module itself, placing them in a separate central control unit. This removes the parasitic current consumption from the module level, allowing the switching element to protect against touch voltages without the penalty of control electronics drawing current from each individual module.
Solution Approach 2:
The patent introduces a central control unit as an intermediary that manages multiple solar modules. This mediator handles all control functions externally, allowing the switching elements in each module to function purely as protective devices without integrated control electronics, thereby eliminating the current loss while maintaining protection capability.
2Reliability
If a semiconductor switching element with control electronics is used, then the solar module can be switched to low resistance state, but the current supplied by the solar module is diminished by the current consumed by the control electronics
Solution Approach 1:
The control electronics are extracted from the solar module and relocated to a central control unit. This separation allows the switching element to retain its switching capability while eliminating the energy consumption of control electronics from the module's current output.
Solution Approach 2:
The switching element is designed to be passive and self-actuating, responding to voltage conditions without requiring active control electronics. The switching element automatically activates when voltage exceeds the threshold, providing protection without consuming operational current, while the central control unit manages the overall system.
3Ease of operation
If direct voltage disconnector switches are used for safety, then the solar array can be disconnected from the AC-DC inverter, but hazardous touch voltages are still present at the current connections of the solar module during assembly, maintenance, or repair
Solution Approach 1:
The switching element is configured to automatically activate and short-circuit the solar cells when the open-circuit voltage exceeds a predetermined threshold. This preliminary protective action occurs automatically during assembly, maintenance, or repair operations, providing protection before manual disconnection switches can be operated.
Solution Approach 2:
The switching element continuously monitors the voltage across the solar cells and automatically responds when the voltage exceeds the safety threshold. This feedback mechanism ensures that protection is activated precisely when needed, regardless of the state of external disconnector switches, thereby eliminating hazardous touch voltages during critical operations.
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
The solution effectively protects against touch voltages by ensuring the solar module is short-circuited when not in use or during malfunctions, maintaining safety without energy consumption and allowing easy integration with other modules.
Implementation Method 1
a pressure actuator is connected to the switching contact. The pressure actuator is configured so as to open the switching contact against the action of a spring element in response to a control pressure above a predetermined threshold
Implementation Method 2
The pressure actuator is configured so as to open the switching contact against the action of a spring element
Data Source
AI summary
A solar module includes a plurality of serially connected photovoltaic solar cells and current connections configured to provide solar current generated by the photovoltaic solar cells and configured for connecting the solar module to at least one additional solar module. A mechanical switching contact is connected in parallel with the serially connected solar cells and a pressure actuator is connected to the switching contact. The pressure actuator is configured so as to open the switching contact against the action of a spring element in response to a control pressure above a predetermined threshold and so as to allow closure of the switching contact by action of the spring element in response to a control pressure below the predetermined threshold. The pressure actuator is connected to a control connection for coupling to a control pressure line.