PV Module Switching Circuit for Safe Series Reconnection
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Solution Overview
Problem
In vehicle-integrated photovoltaic systems, high voltages pose safety risks when PV modules are connected in series, and existing solutions either avoid series connections or require complex communication channels to manage voltage safely.
Innovation Solution
An electronic circuit with PV terminals and string terminals, featuring a disconnector and controller that reverses current flow direction to safely reconnect or disconnect PV modules from the string, allowing for series connections while maintaining safety extra-low voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If PV modules are connected in series to enable high voltage operation, then power output and efficiency are improved, but safety risks increase due to high voltage exposure
Solution Approach 1:
The PV system is divided into modular PV assemblies, each with its own electronic circuit and disconnector. This segmentation allows individual modules to be disconnected from the series string while others remain connected, enabling high voltage operation when needed while maintaining safety by isolating problematic modules. The system can operate at high power with multiple modules in series but can quickly segment and isolate if safety concerns arise.
Solution Approach 2:
An electronic circuit with a disconnector acts as an intermediary between the PV module and the series string. This intermediary component controls the connection state, allowing the module to be safely connected to the high-voltage series configuration when operational efficiency is needed, and safely disconnected when safety risks arise. The disconnector serves as a mediator that manages the trade-off between power output and safety.
2Object-affected harmful factors
If series connections are avoided to maintain safety, then safety risks are reduced, but power output and system efficiency decrease
Solution Approach 1:
The connection configuration of PV modules is made dynamic rather than static. The disconnector in each electronic circuit can switch between connected and disconnected states based on operational conditions. This allows the system to dynamically adjust between safe low-power mode (modules disconnected) and efficient high-power mode (modules connected in series), optimizing both safety and power output at different times.
Solution Approach 2:
The system changes the electrical configuration parameter (connection state) of PV modules based on operational requirements. When safety is the priority, modules are disconnected or configured in parallel configurations. When power output is prioritized and conditions are safe, modules are connected in series configurations. This parameter change allows the system to adapt between safety and efficiency modes.
3Reliability
If decentralized control is implemented to enable safe series connections, then safety and autonomy are improved, but device complexity increases
Solution Approach 1:
Each PV module is equipped with its own electronic circuit and disconnector, enabling it to autonomously monitor its own operational state and make connection decisions without requiring constant central control. This self-service capability improves safety by allowing immediate local response to faults while reducing the complexity of centralized control systems. Each module independently manages its own connection state based on local conditions.
Solution Approach 2:
The electronic circuit serves multiple functions: it monitors module operation, controls the disconnector, communicates with the central system, and manages safety protocols. By consolidating these multiple functions into a single integrated electronic circuit at each module, the system achieves decentralized control and improved safety without proportionally increasing overall device complexity. The multi-functional design reduces the need for separate dedicated components for each function.
Data Source
AI summary
An electronic circuit for a PV module includes PV terminals for coupling to a PV module, and string terminals for coupling to a PV string. A current path runs between the PV terminals and the string terminals, configured to conduct an electric current from the PV module in a first current flow direction to the PV string. The electronic circuit includes a disconnector arranged between a first terminal of the PV terminals and a second terminal of the string terminals, configured to interrupt the current path, in a first state, along the first current path direction and to close the current path, in a second state, along the first current flow direction. The electronic circuit includes a controller, configured to obtain current flow information about a current flow in at least one sub-portion of the current path along a second current flow direction opposite to the first current flow direction.