DC Circuit Breaker Thyristor Commutation Meshed Networks
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Solution Overview
Problem
Existing DC transmission networks face challenges in controlling power flows in meshed line networks, limiting their expansion and reliability, as prior art mainly relies on point-to-point connections without branches or meshes, and lacks effective DC circuit breakers for selective fault management.
Innovation Solution
A DC circuit breaker design featuring a thyristor branch with a commutator device and energy absorber, allowing for quick current zero crossing and selective disconnection of line network parts, enabling a compact, cost-effective, and fail-safe DC line network configuration with meshed configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If point-to-point connections without branches or meshes are used for DC transmission, then the system reliability is improved, but the adaptability of the network is worsened
Solution Approach 1:
The DC circuit breaker is divided into multiple functional segments: a first interrupter for main circuit interruption, a second interrupter for commutation assistance, a commutator device for current transfer, and an energy absorber for fault energy management. This segmentation allows each component to perform its specific function optimally, enabling reliable fault isolation while maintaining network expandability.
Solution Approach 2:
The commutator device acts as an intermediary between the first and second interrupters, facilitating controlled current transfer during the breaking process. This intermediary mechanism enables the coordination between different interrupters, allowing the system to achieve both reliable fault isolation and adaptability for future network expansion.
2Ease of manufacture
If DC circuit breakers are designed with compact and cost-effective configurations, then the ease of manufacture is improved, but the productivity of power interruption is worsened
Solution Approach 1:
The commutator device is pre-configured with capacitors and inductors to store energy before fault occurrence. When a fault is detected, this pre-stored energy is immediately deployed to assist in current commutation and interruption. This preliminary preparation enables fast power interruption without requiring an overly complex real-time response system, maintaining both compactness and high productivity.
Solution Approach 2:
The patent combines multiple functions into integrated components: the commutator device integrates current transfer, energy storage, and voltage control functions; the energy absorber combines fault energy management with circuit isolation. This functional merging reduces the overall system complexity and size while maintaining fast interruption capability.
3Reliability
If selective disconnection of line network parts is implemented, then the reliability is improved, but the device complexity is worsened
Solution Approach 1:
The circuit breaker is segmented into distinct functional modules (first interrupter, second interrupter, commutator device, energy absorber) that can be independently controlled and managed. This modular segmentation enables selective disconnection of specific network parts while keeping the overall device architecture manageable and maintainable.
Solution Approach 2:
The control device automatically detects faults and triggers the appropriate sequence of operations (closing switch, opening second breaker, turning on thyristor, opening first breaker) without external intervention. This self-service capability simplifies the operational complexity while maintaining high reliability for selective fault isolation.
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 solution enables rapid and selective disconnection of line network parts during faults, reducing transient voltages and maximizing the use of DC line networks with meshes, achieving efficient power interruption times comparable to AC networks, and supporting high-voltage direct current transmission.
Implementation Method 1
the additional thyristor branch, with suitable control, makes it possible to force a current zero crossing very quickly
Implementation Method 2
a commutator device and an energy absorber are connected in parallel
Implementation Method 3
a series circuit of a semiconductor switch and a resistor is arranged
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to a direct current circuit breaker (100) with a first to fifth node, wherein . - a first breaker (110) is arranged between the first node (101) and the fourth node (104), . - a second breaker (120) is arranged between the fourth node (104) and the third node (103), . - a parallel circuit of a commutator device (150, 160, 170) is arranged parallel to an energy absorber (180) between the fourth node (104) and the fifth node (105), and a switch (190) is arranged in series to the parallel circuit, and . - a series circuit consisting of a semiconductor switch (260) and a resistor (250) is arranged between the second node (102) and the third node (103).