Semiconductor Breaker Overvoltage Unit With Arc-Contained PCB Fuse
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Solution Overview
Problem
Existing semiconductor circuit breakers face challenges in effectively suppressing overvoltage caused by residual current, leading to potential damage from arcs generated when thermal fuses are blown, which can increase the size of the circuit breaker and compromise protection for both overvoltage suppression elements and internal components.
Innovation Solution
An overvoltage suppression unit is designed with a patterned fuse on a printed circuit board, connecting overvoltage suppression elements in series or parallel, and housed within flame-retardant cases to contain arcs and minimize size, while lead wires connect the suppression elements to semiconductor switches, directing arc discharge away from critical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal fuse is used to disconnect the overvoltage suppression element when overvoltage exceeds a certain level, then the overvoltage suppression element is protected from damage, but an arc may occur between the blown fuse sections causing damage to components inside the circuit breaker
Solution Approach 1:
The patent introduces a protective material as an intermediary substance that absorbs arcs generated when the thermal fuse blows. This material is disposed to surround the lead wires and periphery of the fuse element, acting as a mediator between the arc and the internal components of the circuit breaker, thereby preventing arc damage while maintaining the thermal fuse's overvoltage protection function
Solution Approach 2:
The patent converts the harmful arc energy into a contained phenomenon by using the protective material to absorb and localize the arc. The arc, which would otherwise damage internal components, is transformed into a controlled event that occurs within the protective material's containment zone, thus converting a harmful effect into a manageable one
2Object-affected harmful factors
If a protective material is disposed to surround lead wires and periphery of fuse element to absorb arcs, then arc damage is prevented, but the size of the circuit breaker increases
Solution Approach 1:
The protective material is strategically disposed only in the specific regions where arcs are most likely to occur and cause damage - specifically surrounding the lead wires and periphery of the fuse element. This localized placement provides arc absorption capability precisely where needed, rather than uniformly throughout the entire circuit breaker, thereby minimizing the volume increase while maintaining effective arc protection
3Reliability
If the overvoltage suppression element is used to absorb overvoltage, then internal damage is prevented, but the element may be damaged when voltage exceeds the threshold level causing arc occurrence
Solution Approach 1:
The thermal fuse is configured to blow beforehand when overvoltage exceeds a certain level, disconnecting the overvoltage suppression element from the circuit before the element can be damaged. This prior protective action prevents the element from being exposed to damaging high voltages that would exceed its absorption capability, thereby cushioning the element from potential damage
Solution Approach 2:
The thermal fuse acts as an intermediary protective device that sacrifices itself by blowing to protect the more valuable overvoltage suppression element. The fuse element serves as a mediator that absorbs the initial overvoltage stress through its sacrificial blow, preventing direct damage to the suppression element
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
This configuration effectively protects overvoltage suppression elements and internal components from high voltages and arcs, reducing the size of the semiconductor circuit breaker while ensuring reliable overvoltage suppression and preventing damage from arc discharge.
Implementation Method 1
the overvoltage suppression element 110 has advantages such that internal damage caused by overvoltage may be prevented by effectively absorbing overvoltage generated by the residual current
Implementation Method 2
The thermal fuse is a fuse that is blown according to a temperature. When a temperature in a periphery of the overvoltage suppression element 110 increases due to overvoltage, the thermal fuse is blown to disconnect the overvoltage suppression element from a circuit
Implementation Method 3
as a protective material 220 against an arc, an insulating material is filled inside the case 230, i.e., in a space between the special resin 210 and the case 230 so that an arc generated when the fuse is blown may be absorbed through a protective material inside the case 230
Data Source
AI summary
The present disclosure relates to an overvoltage suppression unit provided in a semiconductor circuit breaker using a semiconductor switch for power, the overvoltage suppression unit comprising: an overvoltage suppression element unit disposed on a first surface of a printed circuit board and including at least one overvoltage suppression element; a pattern fuse connected to the overvoltage suppression element unit and patterned on the first surface of the printed circuit board; a first case forming a housing and covering the first surface of the printed circuit board on which the pattern fuse and the overvoltage suppression element unit are disposed; and a lead wire connected to the pattern fuse, wherein the lead wire is formed so as to connect the first surface of the printed circuit board and a second surface of the printed circuit board.