DC Voltage Circuit Breaker Pulse Generator for Fast Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current direct-current transmission in mesh line networks faces challenges in controlling power flows, necessitating the development of DC voltage circuit breakers to selectively disconnect portions of the line network and prevent failures, especially in high-voltage applications where existing solutions are inefficient and prone to arc formation during current interruption.
Innovation Solution
A DC voltage circuit breaker design featuring a pulse generator circuit with a capacitor, inductor, and switch, along with energy absorbers and hybrid interrupters, enables rapid current zero-crossing and selective disconnection, utilizing semiconductor switches and varistors to manage high voltages and currents, and includes a control device for sequential switching of interrupters to ensure safe disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional DC circuit breaker designs are used, then the structure is simpler, but the current interruption time is longer and arc formation occurs
Solution Approach 1:
The pulse generator circuit is pre-configured with capacitor, inductor, and switch components before fault occurrence. When a fault is detected, the pre-prepared circuit immediately generates a reverse current pulse that forces rapid zero-crossing of the fault current, eliminating the need for gradual current reduction and achieving ultra-fast interruption without arc formation.
Solution Approach 2:
The pulse generator circuit acts as an intermediary mechanism between the fault detection system and the main circuit breakers. It generates a controlled reverse current pulse that mediates the current interruption process, forcing the current to zero-crossing rapidly and enabling the main interrupters to open without experiencing high-current arcs.
2Reliability
If DC voltage circuit breakers are implemented to enable mesh network operation, then the reliability of the line network increases, but the device complexity and cost increase
Solution Approach 1:
The circuit breaker is divided into functionally independent segments: pulse generator circuit (with capacitor, inductor, switch), first interrupter, second interrupter, and energy absorber. Each segment performs a specific function and can be controlled independently, allowing modular design that improves reliability while managing complexity through functional decomposition.
Solution Approach 2:
The circuit breaker dynamically changes electrical parameters during operation. The pulse generator circuit alters current magnitude and direction to force zero-crossing, while the interrupters change from closed to open state. These parameter changes enable rapid fault isolation and improve network reliability without requiring overly complex control mechanisms.
3Loss of time
If rapid current zero-crossing is achieved using pulse generator circuit, then the disconnection time is shortened, but the energy management requirements increase
Solution Approach 1:
The energy absorber is pre-positioned in the circuit to cushion the energy release during fault interruption. When the pulse generator forces rapid current zero-crossing and the interrupters open, the energy absorber is already in place to capture and dissipate the stored energy from the capacitor and inductor, preventing dangerous voltage spikes and protecting the circuit components.
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 allows for rapid and efficient disconnection of line sections in direct-current line networks, reducing the time required for complete current interruption and enabling the construction of meshed direct-current line networks with improved safety and reliability, capable of handling high energies and voltages up to 1200 kV.
Implementation Method 1
a pulse generator circuit is situated between the fourth node and the second node, the pulse generator circuit comprising a parallel connection of a capacitor with a series circuit made up of an inductor and a switch
Implementation Method 2
the pulse generator circuit allows forcing of a current zero-crossing very rapidly
Implementation Method 3
a first energy absorber is situated between the third node and the second node
Implementation Method 4
The switch may be a semiconductor switch, for example, a bipolar transistor having an insulated gate electrode (IGBT) or a thyristor (three-terminal semiconductor rectifier, SCR)
Implementation Method 5
The second interrupter preferably contains a vacuum interrupter. Vacuum interrupters are advantageously suitable for high switching rates and are largely maintenance-free
Implementation Method 6
a first interrupter is merely a simple disconnector or alternatively an SF6 interrupter. SF6 interrupters are advantageously suitable for interrupting very large voltages
Data Source
AI summary
A DC voltage circuit breaker includes a first to fourth nodes, a first interrupter disposed between the first node and the fourth node, a second interrupter disposed between the fourth node and the third node, a pulse generator circuit disposed between the fourth node and the second node, the pulse generator circuit having a capacitor connected in parallel with a series circuit of an inductor and a switch, and a first energy absorber disposed between the third node and the second node.