Component-Level Power Electronics Device Mode Switching for Safety
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Solution Overview
Problem
Photovoltaic power generation systems face safety hazards due to high direct current voltages, which can lead to fires and damage during maintenance, and existing technologies lack effective solutions to mitigate these risks.
Innovation Solution
A power conversion device with a direct current conversion unit, signal processing unit, and controller is introduced, which can switch between normal, safe, and shutdown modes based on communication signals from a next-level power conversion device, thereby reducing voltage and ensuring safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If photovoltaic modules are connected in series to obtain large power generation power, then power generation efficiency is improved, but direct current voltage becomes excessively high causing safety hazards
Solution Approach 1:
The patent divides the series-connected photovoltaic module string into multiple independent groups, with each group managed by a separate inverter. This segmentation reduces the voltage burden on each inverter while maintaining overall system power generation capacity, thereby resolving the contradiction between high voltage requirements for efficiency and safety concerns from excessively high voltage.
Solution Approach 2:
The patent changes the voltage parameter distribution in the system by using multiple inverters operating in parallel, each handling a subset of photovoltaic modules. This parameter change allows the system to maintain high overall power generation while keeping individual inverter voltages at safe levels.
2Power
If high direct current voltage is used on photovoltaic module side, then power generation power is increased, but damage to inverter and safety of maintenance personnel is compromised
Solution Approach 1:
By segmenting the photovoltaic array into multiple groups, each group connects to a separate inverter, the patent distributes the power generation load. This reduces the voltage stress on each individual inverter while maintaining total system power output, thereby protecting inverter durability and improving maintenance safety.
Solution Approach 2:
The patent implements a protection mechanism where inverters monitor their input voltage and automatically disconnect or reduce power when voltage exceeds safe thresholds. This beforehand cushioning prevents inverter damage from overvoltage conditions while maintaining normal high-power operation during safe conditions.
3Productivity
If traditional string photovoltaic power generation is used, then device complexity is reduced, but power generation efficiency is limited
Solution Approach 1:
The patent makes each inverter unit a universal, self-contained module that can independently manage a group of photovoltaic modules. This multi-functionality allows the system to achieve high efficiency through parallel processing while keeping each unit relatively simple, as each inverter performs the same complete set of functions independently.
Data Source
AI summary
A component-level power electronics device is able to switch between a shutdown mode, a normal working mode, and a safe working mode, which includes: when the component-level power electronics device fails to receive the periodic communication signal, maintaining or switching to the shutdown mode; when the periodic communication signal received by the component-level power electronics device includes a heartbeat frame and does not include a voltage adjustment instruction, switching to the normal working mode; or when the periodic communication signal received by the component-level electric power electronics device includes the heartbeat frame and also includes the voltage adjustment instruction, switching to the safe working mode. The three working modes can ensure safety of both a device and a person, have a fast response speed, and are easy to implement.