Laundry treatment machine
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laundry treatment machines using AC pump motors for drain pumps face inefficiencies in speed control, leading to prolonged drainage times and instability in DC terminal voltage, which can cause circuit damage due to repetitive reset operations.
Innovation Solution
A laundry treatment machine with a controller that detects DC terminal voltage drops and controls the inverter and converter to maintain stable power levels, turning off the inverter when voltage drops and operating the converter to increase voltage, thereby preventing repetitive resets and ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If AC pump motor with constant speed operation is used, then the motor can be driven by input AC power, but the drainage period takes a long time due to lack of speed control
Solution Approach 1:
The patent replaces the traditional AC motor with a DC brushless motor, substituting the mechanical/electromagnetic system with a DC-based system that enables electronic speed control. This allows the drainage pump to operate at optimized speeds without the limitations of AC motor constant speed operation, thereby improving drainage productivity while maintaining manageable system complexity through electronic control.
Solution Approach 2:
The patent implements variable speed control for the DC brushless motor, transitioning from constant speed operation to dynamic speed adjustment. The motor speed can be varied according to drainage requirements, allowing optimal performance across different operating conditions. This dynamic control capability directly addresses the limitation of AC motors while keeping the control system integrated and manageable.
2Productivity
If DC brushless motor with speed control is used, then drainage speed can be controlled, but the drainage completion period takes a long time
Solution Approach 1:
The patent implements periodic action through the controller that alternates between operating the inverter and charging the capacitor based on DC terminal voltage levels. When voltage drops below a threshold, the inverter is turned off and the capacitor is charged; when voltage is sufficient, the inverter operates to drive the motor. This periodic control pattern optimizes both speed control capability and drainage completion time by preventing unnecessary delays while maintaining efficient operation.
Solution Approach 2:
The patent employs feedback control by continuously monitoring the DC terminal voltage and adjusting the inverter operation accordingly. The controller detects voltage levels and uses this information to determine when to switch between inverter operation and capacitor charging modes. This feedback mechanism ensures optimal drainage performance by adapting the motor speed to real-time electrical conditions, preventing both excessive speed reduction and unnecessary delays.
3Productivity
If inverter operates continuously, then AC power can be supplied to motor, but DC terminal voltage continuously drops causing unstable operation and circuit damage
Solution Approach 1:
The patent applies preliminary action by charging the capacitor before the DC terminal voltage drops to critical levels. The controller monitors voltage continuously and initiates capacitor charging when voltage approaches the threshold, preventing voltage collapse before it occurs. This proactive approach maintains stable circuit operation and prevents damage by ensuring sufficient voltage headroom is maintained throughout the drainage process.
Solution Approach 2:
The patent implements periodic action through alternating inverter operation and capacitor charging cycles. The controller switches between these modes based on real-time voltage monitoring, creating a rhythmic pattern of power delivery and energy storage. This periodic operation prevents continuous voltage depletion while maintaining steady drainage performance, thereby improving both productivity and circuit reliability through balanced power management.
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 stabilizes the operation of the drain pump, reduces drainage time, and minimizes the risk of circuit damage by maintaining power within a controlled range and preventing repetitive reset operations.
Implementation Method 1
an inverter configured to convert the DC power from the converter into AC power by a switching operation and output the AC power to the motor
Implementation Method 2
a converter configured to output DC power
Implementation Method 3
a motor configured to operate the drain pump
Data Source
AI summary
Provided is a laundry treatment machine including a washing tub, a washing tub motor configured to rotate the washing tub, a drain pump configured to operate to drain the washing tub, a motor configured to operate the drain pump, a converter configured to output DC power, an inverter configured to convert the DC power, a dc terminal voltage detector configured to detect a dc terminal voltage output from the converter, and a controller configured to, when the dc terminal voltage continuously drops during a first period based on an operation of the inverter, perform control to turn off the inverter and operate the converter after the first period. Accordingly, it is possible to stably drive based on the dc terminal voltage during the operation of the drain pump.