Photovoltaic Power Conversion Circuit Rapid Shutdown Control
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Solution Overview
Problem
Photovoltaic power systems face complexity and high costs due to the need for communication between modules during rapid shutdown and restart, which is typically achieved through power lines or wireless communication, making it difficult to meet safety voltage regulations efficiently.
Innovation Solution
A method and circuit structure that control current flow between power conversion and inversion circuits using a control circuit to regulate current and switch states based on a rapid shutdown signal, allowing for simplified communication and voltage regulation, thereby enabling safe shutdown and restart while reducing system complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power lines or wireless communication are used for communication between photovoltaic modules during rapid shutdown, then communication functionality is achieved, but system complexity and cost increase
Solution Approach 1:
The patent applies self-service by having the rapid shutdown signal propagate automatically through the existing power conversion circuitry without requiring separate communication infrastructure. Each power conversion circuit detects the shutdown signal from its upstream neighbor and autonomously executes shutdown, eliminating the need for external communication systems.
Solution Approach 2:
The patent makes the power conversion circuit serve dual functions: both power processing and communication/shutdown signal transmission. The existing power lines and control circuits are utilized for both their primary electrical function and as a medium for transmitting shutdown commands, removing the need for dedicated communication hardware.
2Reliability
If communication systems are added to photovoltaic modules for rapid shutdown control, then shutdown functionality is achieved, but system cost increases
Solution Approach 1:
The system uses existing components to perform communication functions, eliminating the need for additional communication modules. Each power conversion circuit uses its own control circuitry to detect and respond to shutdown signals, making the system self-sufficient without expensive added components.
Solution Approach 2:
The control circuit in each power conversion circuit is designed to handle both normal operation control and shutdown signal detection, making it a multi-functional component that reduces overall system cost by eliminating dedicated communication hardware.
3Object-affected harmful factors
If voltage is reduced to meet safety regulations during shutdown, then safety compliance is achieved, but power conversion circuit operation is disrupted
Solution Approach 1:
The patent segments the photovoltaic system into independent power conversion circuits, each capable of autonomous shutdown. This segmentation allows individual circuits to be shut down without affecting the entire system, maintaining safety while preserving operational flexibility for remaining circuits.
Solution Approach 2:
The system dynamically adjusts operation based on shutdown signals, transitioning from normal power conversion mode to shutdown mode. During shutdown, the circuit dynamically reduces voltage output to meet safety requirements, then dynamically returns to normal operation when the shutdown condition is cleared, optimizing both safety and productivity.
Data Source
AI summary
A method of controlling a photovoltaic power system, can include: controlling a first current flowing through a connection line between an output terminal of a power conversion circuit and an input terminal of an inversion circuit according to a rapid shutdown signal; and controlling operation states of the power conversion circuit coupled to a photovoltaic panel in accordance with the first current, such that a voltage on the connection line meets preset requirements. A photovoltaic power system can include: an inversion circuit configured to be controlled to regulate a first current of an input line of the inversion circuit; and at least one power conversion circuit coupled in series with the input line, and being configured to transition among different operation states according to the first current.