PV Module Voltage Clamping Circuit for Fill Factor Improvement
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Solution Overview
Problem
Conventional photovoltaic (PV) modules face challenges in maintaining optimal voltage margins and fill factor due to overvoltage conditions, which require expensive and bulky components in the converter to handle high voltage ranges.
Innovation Solution
A voltage clamping circuit is introduced to regulate the input voltage of PV modules, using switches and hysteresis controllers to prevent overvoltage conditions, thereby reducing the voltage margin required for the converter and improving the fill factor by maintaining the input voltage below the open-circuit voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PV modules are connected in series to produce high output voltage, then the voltage margin required by the converter increases, but the fill factor decreases and expensive components are required
Solution Approach 1:
The patent changes the voltage parameter by introducing a voltage clamping circuit that actively regulates the input voltage to the converter. The circuit monitors the PV module output voltage and uses switching elements to clamp the voltage at a predetermined level, transforming the unregulated high voltage output into a controlled voltage that maintains optimal fill factor while still providing sufficient voltage margin for the converter operation
2Reliability
If the voltage margin is increased to accommodate high output voltage from PV modules, then overvoltage conditions are prevented, but the converter requires expensive components capable of tolerating large voltage ranges
Solution Approach 1:
The voltage clamping circuit acts as an intermediary between the PV module and the converter. It includes voltage monitoring circuitry that detects the PV module output voltage and controls switching elements to clamp the voltage at a predetermined level. This intermediary circuit protects the converter from overvoltage conditions while allowing the converter to use less expensive components with narrower voltage tolerance specifications
3Temperature
If the full output power from PV module is dissipated by the conversion circuitry during overvoltage conditions, then the voltage is regulated, but energy efficiency decreases
Solution Approach 1:
The voltage clamping circuit employs periodic switching action rather than continuous power dissipation. The switching elements are turned on and off in a controlled manner to maintain voltage at the predetermined level. This periodic action allows the circuit to regulate voltage while minimizing energy loss, as the switching elements conduct only during brief intervals when voltage exceeds the clamp level, rather than continuously dissipating full output power
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 voltage clamping circuit reduces the need for costly and space-consuming components in the converter, enhancing the fill factor and allowing higher output voltage PV modules to operate with lower input voltage converters, thus improving efficiency and cost-effectiveness.
Implementation Method 1
using switches and hysteresis controllers to prevent overvoltage conditions
Data Source
AI summary
A method and apparatus for voltage clamping including: measuring a DC voltage across the PV module at an input of a power converter, comparing the measured DC voltage to the overvoltage threshold, determining the measured DC voltage exceeds the overvoltage threshold, and operating a clamping circuit to clamp at least a portion of the DC voltage prior to input to the power converter.