Solar Module Voltage Limiting Controller for PV String Safety
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Solution Overview
Problem
Conventional solar photovoltaic systems are limited by safety regulations regarding maximum voltage, leading to reduced power generation and limited number of solar modules that can be connected in series, as they operate below safety limits to prevent voltage exceedance.
Innovation Solution
The system employs a controller and local management units to monitor and control the voltage provided by each solar module to the string bus, allowing for operation closer to regulatory limits by limiting the voltage output based on predicted future voltage and historical trends, thereby enabling more modules to be connected while maintaining safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solar modules are designed to operate at voltages well below regulatory or safety limits to prevent voltage exceedance, then safety is improved, but power generation is reduced
Solution Approach 1:
The patent implements dynamic voltage management by continuously monitoring environmental conditions (temperature, irradiance) and adjusting the operating voltage of solar modules in real-time. The system transitions from static voltage design to dynamic voltage control, allowing the array to operate closer to safety limits when conditions permit while maintaining safety margins when conditions change. This resolves the contradiction by making the voltage operation point adaptive rather than fixed.
Solution Approach 2:
The system employs feedback mechanisms through voltage sensors and environmental sensors that continuously monitor the actual voltage output and operating conditions. This feedback information is used to adjust the operating parameters of solar modules, enabling the system to maintain optimal power generation while staying within safety limits. The feedback loop allows the system to respond to changing conditions and maintain the balance between safety and productivity.
2Reliability
If the number of solar modules connected in series is limited to stay below regulatory or safety limits, then safety is improved, but the total output power of the system is reduced
Solution Approach 1:
The patent changes the operational parameters of solar modules by adjusting their operating voltage dynamically based on environmental conditions and array configuration. Instead of fixing the number of series-connected modules, the system modifies the voltage output parameter of individual modules to achieve higher total power while maintaining compliance with safety limits. This allows flexible optimization of the power-safety trade-off.
Solution Approach 2:
The system transforms the static configuration of series-connected modules into a dynamic system where the effective voltage contribution of each module can be adjusted in real-time. This dynamic approach allows the system to maximize the number of series-connected modules while using active control to prevent voltage exceedance, thereby increasing total output power without compromising safety.
3Reliability
If solar modules are combined in limited numbers to operate below regulatory or safety limits, then safety is improved, but the number of solar modules that can be connected in series is limited
Solution Approach 1:
The system uses feedback from voltage monitoring and environmental sensing to dynamically determine the optimal number of series-connected modules. Rather than using a fixed conservative limit, the feedback mechanism allows the system to safely increase the number of series-connected modules when conditions support higher voltages, thereby increasing productivity while maintaining safety through continuous monitoring and adjustment.
Data Source
AI summary
Apparatuses and methods are disclosed for regulating or limiting the voltage output from solar modules connected in series such that the voltage on a string bus connecting those solar modules does not exceed regulatory or safety limitations. This can be accomplished via a controller, local management units (for downconverting solar module voltage output), or a combination of the two.