HVDC Converter Protection Module Using Electromagnetic Busbar Repulsion
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Solution Overview
Problem
Existing protection circuits for power semiconductor devices in HVDC converters do not effectively safeguard against both high current surges and electrical discharges from capacitors, leading to potential damage during switching failures.
Innovation Solution
An electronic module with a short circuit device connected in parallel to the capacitor, comprising a movable busbar, a short circuit portion, and a spring element, which generates an electromagnetic force to create a short circuit path when high currents are detected, bypassing the capacitor and preventing damage to the power semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If screw connections are used to connect busbars to power modules, then strong mechanical strength is achieved, but assembly complexity and cost increase
Solution Approach 1:
The connection system uses different connection types for different locations: screw connections are used only where high mechanical strength is required (busbar to capacitor), while plug and socket connections are used where ease of assembly is prioritized (busbar to power module). This local differentiation of connection quality optimizes both strength and manufacturability.
Solution Approach 2:
The connection system incorporates a movable portion that can dynamically change its position and electrical connection state. The movable portion can move between a first position (normal operation) and a second position (short circuit), providing dynamic adaptability that reduces the need for overly robust static connections throughout the entire system.
2Reliability
If a short circuit path is created during short circuit state, then power semiconductors are protected from high currents, but the capacitor discharge energy can still damage the power modules
Solution Approach 1:
The spring element is pre-loaded in a compressed state during normal operation, storing potential energy in advance. When a fault condition occurs, this pre-stored energy is rapidly converted to kinetic energy, quickly moving the movable portion to establish the protective short circuit path before the capacitor discharge can damage the power modules.
Solution Approach 2:
The spring element's expansion, which could be seen as a disruptive mechanical movement, is converted into a beneficial protective action. The mechanical expansion directly creates the electrical short circuit path that bypasses the power semiconductor device, turning a mechanical force into an electrical protection mechanism.
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
Effectively protects power semiconductor devices from high current surges and electrical discharges by creating a short circuit path for excessive currents, preventing damage and allowing for cost-saving plug and socket connections, reducing wear and tear, and ensuring stable operation.
Implementation Method 1
when a short circuit current flows through the first busbar an electromagnetic force between the two busbars causes the first busbar to repel the second busbar and move towards the short circuit portion
Data Source
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Figure 3
AI summary
The present invention discloses an electronic module for protecting power semiconductor devices of an HVDC converter against high current surges and damaging electrical discharges. It comprises a capacitor, a short circuit device, a movable portion, a short circuit portion and a spring element. The short circuit device is connected in parallel to the capacitor. The short circuit device comprises a first and a second busbar. The movable portion is connected to the first busbar and the short circuit portion is connected to the second busbar. The spring element is arranged between the movable portion and the short circuit portion. When a short circuit current flows through the first busbar an electromagnetic force between the two busbars causes the first busbar to repel the second busbar and move towards the short circuit portion. The short circuit portion provides a short circuit path connecting the first busbar to the second busbar short circuiting the capacitor and bypassing the power semiconductor devices of the HVDC converter.