Refrigerator Multi-Door Motor Control to Reduce Inrush Current

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Solution Overview

Problem

Existing refrigerators face challenges in efficiently opening and closing multiple doors with minimal power consumption, particularly due to the high inrush currents and counter electromotive forces generated when multiple motors are started simultaneously, necessitating a high-capacity power supply.

Innovation Solution

A refrigerator system that controls the order and timing of motor operation for multiple doors, starting each motor after a delay to minimize inrush currents, using smaller operating currents until doors are partially open, and adjusting motor RPM based on door weight and angle, allowing for synchronized door opening and closing with reduced power requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple motors are driven simultaneously to open multiple doors, then the door opening function is achieved, but the inrush current becomes excessively high requiring a high-capacity power supply

Engineering Contradiction:

Improvedoor opening speedVSAvoidinrush current

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The system performs preliminary action by opening one door completely before starting to open the second door. The processor controls the first motor to open the first door, and only after the first door is fully opened does it start driving the second motor to open the second door. This sequential approach prevents simultaneous inrush currents from adding up, thereby reducing the peak power requirement while maintaining efficient door opening functionality.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a high-capacity power supply is provided to drive multiple motors simultaneously, then the door opening function is reliable, but the device complexity and cost increase

Engineering Contradiction:

Improvedoor opening reliabilityVSAvoidpower supply capacity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

3Speed

If motors are driven with high power to overcome pressure difference quickly, then the door opens rapidly, but the power consumption increases

Engineering Contradiction:

Improvedoor opening speedVSAvoidmotor power consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The system applies periodic action by controlling motors to operate in distinct phases rather than continuously at high power. The processor first drives the first motor to open the first door, waits for it to complete opening, then drives the second motor to open the second door. This phased operation reduces overall power consumption compared to driving all motors simultaneously at high power, while still achieving rapid door opening through optimized sequencing.

Inventive Principle:

Principle #19Periodic 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

The system efficiently opens and closes multiple refrigerator doors with minimal power consumption by optimizing motor operation, reducing the need for high-capacity power supplies and ensuring synchronized door movements.

Implementation Method 1

a large power is necessary due to a difference in pressure between the inside and the outside of a refrigeration compartment

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

a magnitude of an inrush current applied to the first motor by starting the driving of the first motor

Methodology Applied

Scientific EffectInrush current:

Implementation Method 3

a time after a counter electromotive force is generated on the second motor by starting the driving of the second motor

Methodology Applied

Scientific EffectCounter electromotive force: Electromagnetic Induction

Data Source

PatentEP4153923B1Refrigerator and controlling method thereof

Publication Date: 2025.09.17 SAMSUNG ELECTRONICS CO LTD

Figure 1a~1b
Figure 1c(a)~1c(c)
Figure 2a(a)~2a(b)

AI summary

A refrigerator and a controlling method thereof are provided. The refrigerator includes a main body including first and second doors, a first motor for opening the first door and a second motor for opening the second door, and a processor configured to, based on a user command for opening the door being obtained, start driving the first motor to open the first door, and after a first time from the time when the first motor has started being driven, start driving the second motor to open the second door.