Semiconductor Switch Abnormal Energy Protection Circuit

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Solution Overview

Problem

The use of relay switches for abnormal energy protection in power conversion systems is costly, occupies large space on printed circuit boards, generates heat, reduces efficiency, and has reliability issues due to mechanical structure and complex circuit design.

Innovation Solution

A power conversion system with abnormal energy protection that includes a plurality of DC input power sources, DC power converters, and two output capacitors, utilizing a protection circuit with semiconductor switches and diodes to decouple DC input power sources from output capacitors in case of abnormality, reducing heat losses and increasing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If relay switches are used for abnormal energy protection, then protection function is achieved, but cost increases and space occupation increases

Engineering Contradiction:
Improveprotection functionVSAvoidspace on printed circuit board
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent replaces mechanical relay switches with semiconductor switches (MOSFETs or IGBTs) that are integrated into the DC power converters. This substitution eliminates the need for separate mechanical protection devices, reducing space occupation on the printed circuit board while maintaining the abnormal energy protection function through controlled switching operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The DC power converters are designed to perform both their primary power conversion function and the secondary function of abnormal energy protection. By integrating the protection capability into the existing power converters, the system achieves multi-functionality, eliminating the need for dedicated protection devices and reducing overall space requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If relay switches are used for abnormal energy protection, then protection function is achieved, but heat generation increases and efficiency decreases

Engineering Contradiction:
Improveprotection functionVSAvoidheat losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces mechanical relay switches with semiconductor switches (MOSFETs or IGBTs) that have lower on-resistance and switching losses. This substitution significantly reduces heat generation during normal operation and during protection events, thereby improving overall system efficiency while maintaining reliable abnormal energy protection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If relay switches are used for abnormal energy protection, then protection function is achieved, but device complexity and cost increase

Engineering Contradiction:
Improveprotection functionVSAvoidcircuit design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the abnormal energy protection function into the existing DC power converters, making them multi-functional devices. This integration eliminates the need for separate protection circuits and relay switch control logic, thereby reducing device complexity and lowering costs while maintaining reliable protection functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3627678B1Power conversion system with abnormal energy protection and method of operating the same
Publication Date: 2023.04.26 DELTA ELECTRONICS INC(CN)
  • EP3627678B1 patent drawingFigure 1
  • EP3627678B1 patent drawingFigure 2A
  • EP3627678B1 patent drawingFigure 2B

AI summary

A power conversion system with abnormal energy protection includes a plurality of DC input power sources (Vdc1-Vdcn), a plurality of DC power converters (11-1n), two output capacitors (41,42), and a protection circuit (20). An input side of each DC power converter (11-1n) is correspondingly coupled to one of the DC input power sources (Vdc1-Vdcn), and output sides of the DC power converters (11-1n) are coupled in parallel to each other to form a DC output bus (30). Two output capacitors (41,42) are coupled in series between a positive voltage end (Vb+) and a negative voltage end (Vb-) of the DC output bus (30). The protection circuit (20) is coupled between the DC input power sources (Vdc1-Vdcn) and the two output capacitors (41,42). When one of the two output capacitors (41,42) is abnormal, the protection circuit (20) decouples the DC input power sources (Vdc1-Vdcn) from the two output capacitors (41,42) in a shorted-circuit manner.