Battery Cluster Fuse Coordination to Prevent Overcurrent Impulses

Solution Overview

Problem

Conventional high voltage battery clusters face safety issues due to large current and voltage impulses caused by simultaneous fusion of two fuses during overcurrent faults, leading to potential electrical hazards.

Innovation Solution

An overcurrent protection circuit with two fusing modules having different withstand current-time curves, where one module fuses before the other to prevent simultaneous fusion, reducing current and voltage impulses by ensuring only one fuse disconnects the cluster.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two fuses are arranged in positive and negative branches for overcurrent protection, then circuit safety is improved, but large current and voltage impulses are generated when both fuses fuse simultaneously

Engineering Contradiction:

Improvecircuit safetyVSAvoidcurrent and voltage impulses

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by designing the positive and negative branch fuses with different specifications (different rated currents and melting characteristics). This ensures that during an overcurrent event, one fuse will blow before the other, preventing simultaneous fusion. The asymmetric design creates a controlled sequence where the first fuse interrupts the current path before the second fuse reaches its melting point, thereby eliminating the harmful current and voltage impulses that would otherwise be generated by simultaneous fuse failure.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent implements preliminary action by selecting fuse specifications such that one fuse (the first fuse) is designed to blow before the other fuse under overcurrent conditions. This preliminary blowing of the first fuse preemptively interrupts the current path, preventing the second fuse from reaching its melting point and blowing simultaneously. The preliminary action of the first fuse blowing eliminates the conditions that would lead to harmful current and voltage impulses.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If two fuses fuse simultaneously during overcurrent fault, then circuit disconnection is achieved, but large reverse voltage is generated affecting electrical safety

Engineering Contradiction:

Improvecircuit disconnectionVSAvoidreverse voltage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by designing the positive and negative branch fuses with different specifications (different rated currents and melting characteristics). This ensures that during an overcurrent event, one fuse will blow before the other, preventing simultaneous fusion. The asymmetric design creates a controlled sequence where the first fuse interrupts the current path before the second fuse reaches its melting point, thereby eliminating the harmful current and voltage impulses that would otherwise be generated by simultaneous fuse failure.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent implements preliminary action by selecting fuse specifications such that one fuse (the first fuse) is designed to blow before the other fuse under overcurrent conditions. This preliminary blowing of the first fuse preemptively interrupts the current path, preventing the second fuse from reaching its melting point and blowing simultaneously. The preliminary action of the first fuse blowing eliminates the conditions that would lead to harmful current and voltage impulses.

Inventive Principle:

Principle #10Preliminary action

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 solution effectively reduces current and voltage impulses during disconnection, enhancing electrical safety by avoiding the superposition of current change rates and prolonging fusing duration, thus minimizing the risk of electrical hazards.

Implementation Method 1

A withstand current-time curve of the first fusing module is different from a withstand current-time curve of the second fusing module... two fuses are both fused when the overcurrent fault occurs in the circuit, and a drawn arc thus generated may cause a large current change rate

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS11942775B2High voltage battery cluster, and overcurrent protection circuit and switch box thereof

Publication Date: 2024.03.26 SUNGROW POWER SUPPLY CO LTD

AI summary

A high voltage battery cluster, and an overcurrent protection circuit and a switch box of the high voltage battery cluster are provided. The overcurrent protection circuit includes a first fusing module and a second fusing module. Since a withstand current-time curve of the first fusing module is different from a withstand current-time curve of the second fusing module, in a case that an overcurrent fault occurs in a high voltage battery cluster, one fusing module can cause an open circuit in the high voltage battery cluster prior to another fusing module, thereby preventing the high voltage battery cluster from being broken by a large current when an overcurrent fault occurs in the high voltage battery cluster, thus ensuring an electrical safety of the high voltage battery cluster.