TRIAC Motor Voltage Control for Laundry Machine Power Regulation

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Solution Overview

Problem

Electric motors in laundry treatment machines and dishwashers face high costs and power consumption due to the need for synchronous motors with high maximum safe voltages to withstand unpredictable mains voltage variations, leading to potential overheating and thermal protection system interventions. Additionally, existing solutions fail to efficiently regulate electric power supply based on specific operation cycles and motor characteristics.

Innovation Solution

A power supply apparatus using a TRIAC with a controller that senses supply voltage and generates driving signals to set a firing angle, allowing the electric motor to operate within safe voltage limits, temporarily increasing voltage for starting and reducing it during steady-state operations, thereby optimizing power usage and reducing noise and consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If synchronous motors with high maximum safe voltages are used to withstand unpredictable mains voltage variations, then the reliability of the motor is improved, but the cost and power consumption increase significantly

Engineering Contradiction:
Improvemotor reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the operating voltage parameter dynamically by using a TRIAC to control the firing angle, thereby regulating the RMS voltage supplied to the motor. This allows the motor to operate at lower voltages (reducing power consumption) while still maintaining reliability through active voltage regulation that prevents harmful voltage excursions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a TRIAC as an intermediary device between the mains voltage source and the motor. The TRIAC acts as a voltage regulator that mediates the voltage delivery, allowing the system to use lower-cost motors while maintaining reliability through active voltage control rather than relying on motors designed for high voltage tolerance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If synchronous motors with high maximum safe voltages are used to withstand unpredictable mains voltage variations, then the reliability of the motor is improved, but the cost increases significantly

Engineering Contradiction:
Improvemotor reliabilityVSAvoidmotor cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the operating voltage parameter dynamically by using a TRIAC to control the firing angle, thereby regulating the RMS voltage supplied to the motor. This allows the motor to operate at lower voltages (reducing power consumption) while still maintaining reliability through active voltage regulation that prevents harmful voltage excursions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a TRIAC as an intermediary device between the mains voltage source and the motor. The TRIAC acts as a voltage regulator that mediates the voltage delivery, allowing the system to use lower-cost motors while maintaining reliability through active voltage control rather than relying on motors designed for high voltage tolerance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If the supply voltage is increased to provide sufficient power for motor operation, then the power delivery is improved, but the motor temperature rises causing thermal protection system intervention

Engineering Contradiction:
Improvepower deliveryVSAvoidmotor temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The patent implements dynamic voltage control by continuously adjusting the TRIAC firing angle based on actual voltage conditions and motor requirements. This dynamic approach allows the system to deliver sufficient power when needed while preventing excessive voltage that would cause overheating, thereby resolving the contradiction between power delivery and temperature control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs a feedback control system that monitors the supply voltage and adjusts the TRIAC firing angle accordingly. The controller receives voltage information and modifies the triggering signal to maintain appropriate voltage levels, preventing motor overheating while ensuring sufficient power delivery for operation.

Inventive Principle:
Principle #23Feedback

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 reduces power consumption by up to 25% and minimizes overheating, enabling the use of cheaper motors while maintaining safe operation, and dynamically adjusts power supply to match specific washing or drying cycles, reducing noise and energy expenditure.

Implementation Method 1

The power supply apparatus comprises a TRIAC (TRIode for Alternating Current) having a first anode terminal coupled with a first terminal of an AC electric power supply and a second anode terminal coupled with a first terminal of the electric motor

Methodology Applied
Scientific EffectTRIAC switching:

Implementation Method 2

The electronic unit comprises a sensing unit configured to sense the supply voltage at the second terminal of the AC electric power supply and to provide a corresponding sensed voltage to the controller

Methodology Applied
Scientific EffectVoltage sensing:

Implementation Method 3

The controller is further configured to set the driving signal for activating the TRIAC with a firing angle based on the sensed voltage, based on the sensed gate voltage, and based on an electric motor target voltage

Methodology Applied
Scientific EffectPhase angle control:

Data Source

PatentEP3314051B1Power supply regulation in laundry treatment machines or dishwashers
Publication Date: 2019.04.03 ELECTROLUX APPLIANCES
  • EP3314051B1 patent drawingFigure 1
  • EP3314051B1 patent drawingFigure 2
  • EP3314051B1 patent drawingFigure 3A

AI summary

A laundry treatment machine (100; 400) or a dishwasher is provided, comprising: - a washing and/or drying assembly configured to carry out washing and/or drying cycles; - an electronic unit (190) configured to drive the washing and/or drying assembly to carry out the washing and/or drying cycles, wherein: - the washing and/or drying assembly comprises a device (170; 177; 450) adapted to be operated by, or comprising, an electric motor; - the electronic unit (190) comprises a power supply apparatus (200) for supplying electric power to the electric motor, the power supply apparatus (200) comprising: - a TRIAC (205) comprising a first anode terminal (Ml) coupled with a first terminal (TN) of an AC electric power supply and a second anode terminal (M2) coupled with a first terminal of the electric motor, the electric motor comprising a second terminal coupled with a second terminal (TL) of the AC electric power supply for receiving a supply voltage; - a controller (215) configured to generate a driving signal, and - a triggering circuit (208) for activating the TRIAC (205) by providing triggering pulse signals to a third, gate terminal (G) of the TRIAC (205) based on the driving signal received from the controller (215); - the electronic unit (190) further comprises: - a sensing unit (260) configured to sense the voltage at the second terminal (TL) of the AC electric power supply and to provide a corresponding sensed supply voltage to the controller (215), - a feedback circuit branch (230) connected between the gate terminal (G) of the TRIAC (205) and an input terminal of the controller (215) for providing a corresponding sensed gate voltage to the controller (215), wherein the controller (215) is further configured to: set the driving signal for activating the TRIAC (205) with a firing angle based on the sensed supply voltage, based on the sensed gate voltage and based on an electric motor target voltage in such a way to supply the electric motor with a corresponding operating voltage, such operating voltage being lower than or substantially equal to said supply voltage.