Drain Pump Inverter Control for Sensorless Variable-Speed Operation
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Solution Overview
Problem
Conventional drain pump motors driven by AC voltage lack speed control during drainage, leading to extended drainage times due to constant speed operation, which is inefficient and unstable.
Innovation Solution
A drain pump driving apparatus that converts AC voltage to DC voltage, using a voltage dropper, inverter module, and controller to adjust and control the motor output, enabling sensorless operation and stable motor speed control, thereby improving converter stability and reducing drainage time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If AC voltage is used to drive the drain pump motor with constant speed operation, then the device complexity is reduced, but the drainage time is extended and productivity decreases
Solution Approach 1:
The patent applies parameter changes by converting the motor from constant speed operation to variable speed operation through frequency conversion. The controller adjusts the frequency and voltage of the AC power supplied to the motor, enabling speed variation to optimize drainage efficiency while managing converter stability.
Solution Approach 2:
The patent implements dynamics by transitioning from static constant speed control to dynamic variable speed control. The system continuously adjusts motor speed based on real-time conditions, allowing the drainage process to adapt to changing loads and maintain optimal performance throughout operation.
2Device complexity
If AC voltage with constant speed operation is used, then the device complexity is reduced, but the stability of operation deteriorates
Solution Approach 1:
The patent employs feedback control mechanisms where the controller monitors motor operation parameters and adjusts the inverter module accordingly. This closed-loop control ensures stable motor operation by compensating for variations and maintaining optimal performance conditions throughout the drainage process.
Solution Approach 2:
The patent uses parameter changes to maintain stability by dynamically adjusting voltage and frequency parameters. The controller modifies these parameters in response to operational conditions, ensuring the motor operates within stable ranges while adapting to changing drainage requirements.
3Device complexity
If sensorless control is implemented, then the device complexity is reduced by removing sensors, but the measurement precision of motor parameters deteriorates
Solution Approach 1:
The patent applies self-service by implementing sensorless control where the controller estimates motor parameters through calculation based on electrical measurements. The system uses current and voltage data to derive speed and position information without requiring physical sensors, thereby reducing complexity while maintaining adequate control precision.
Solution Approach 2:
The patent replaces mechanical sensor-based measurement systems with electrical calculation-based estimation. The controller computes motor parameters from electrical signals using mathematical models, substituting physical sensing mechanisms with computational methods to reduce hardware complexity.
4Productivity
If voltage control is implemented to maintain constant power, then the productivity is improved by reducing drainage time, but the device complexity increases due to additional voltage control components
Solution Approach 1:
The patent merges the voltage control function into the existing inverter module and controller. By integrating voltage adjustment capabilities within the frequency conversion system, the patent achieves constant power control without adding separate voltage control hardware, thereby improving productivity while minimizing increases in device complexity.
Solution Approach 2:
The patent implements multi-functionality by designing the inverter module and controller to perform both frequency conversion and voltage control functions. This universal approach allows a single integrated system to achieve variable speed control and constant power maintenance, improving drainage efficiency without proportionally increasing system complexity.
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 solution allows for stable and efficient motor operation, reducing drainage time and improving converter stability by maintaining constant power control, which enhances the overall performance of the laundry treatment machine.
Implementation Method 1
a converter to convert alternating current (AC) voltage into direct current (DC) voltage
Implementation Method 2
an inverter module to operate based on a first voltage from the voltage dropper and to output AC voltage converted by a switching operation
Data Source
AI summary
The present disclosure relates to a drain pump driving apparatus and a laundry treatment machine including the same. A drain pump driving apparatus according to an embodiment of the present disclosure includes: a converter; a voltage dropper to drop the DC voltage from the converter; an inverter module to operate based on a first voltage from the voltage dropper and to output AC voltage converted by a switching operation to a drain pump motor; a controller to operate based on a second voltage from the voltage dropper and to control the inverter module; and a voltage adjuster to adjust the level of voltage information of the motor outputted from the inverter module and to output the adjusted voltage information to the controller. Accordingly, it is possible to stably drive the drain motor.