Home appliance comprising power converter employing overheating prevention method
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Solution Overview
Problem
Existing cordless cleaners face overheating issues during battery charging and discharging, which can damage components without effective protection mechanisms.
Innovation Solution
A method using a DC link capacitor, divider resistor, temperature sensor, PWM controller, and switch to detect overheating and cut off switching to prevent damage, employing a transformer for output voltage conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If battery charging and discharging operations are performed in cordless cleaners, then power conversion is enabled, but overheating occurs that can damage components
Solution Approach 1:
The temperature sensor continuously monitors temperature before critical overheating occurs, and the PWM controller is pre-configured to cut off switching when temperature thresholds are reached, preventing damage before it happens
Solution Approach 2:
The temperature sensor provides continuous feedback to the PWM controller about the temperature condition, which automatically adjusts the switching operation to maintain safe operating temperatures during power conversion
2Reliability
If temperature monitoring is implemented to prevent overheating, then component protection is improved, but device complexity increases
Solution Approach 1:
The PWM controller automatically monitors temperature and self-regulates the switching operation based on temperature feedback, eliminating the need for separate complex protection circuits and microcontroller interventions
Solution Approach 2:
The temperature monitoring and protection functions are merged into the existing PWM controller's operational parameters, integrating protection logic into the power conversion control itself rather than adding separate protection systems
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
Effectively prevents overheating by detecting temperature changes and cutting off power to the switch, safeguarding the cleaner's components and ensuring safe operation.
Implementation Method 1
a direct current (DC) link capacitor configured to smooth an alternating current input voltage
Implementation Method 2
a first temperature sensor connected in series to the at least one divider resistor, and configured to, together with the at least one divider resistor, divide the voltage across the DC link capacitor, wherein a resistance of the first temperature sensor changes according to a temperature
Implementation Method 3
a transformer configured to convert an output alternating current voltage generated according to a switching operation of the switch
Data Source
AI summary
A home appliance is provided. The home appliance includes a direct current (DC) link capacitor configured to smooth an alternating current input voltage, at least one divider resistor configured to divide a voltage across the DC link capacitor, a first temperature sensor connected in series to the at least one divider resistor, and configured to, together with the at least one divider resistor, divide the voltage across the DC link capacitor, wherein a resistance of the first temperature sensor changes according to a temperature, a pulse-width modulation (PWM) controller configured to determine whether overheating has occurred, based on a change in a voltage between a first point and a ground, wherein the first point is a connection point between the at least one divider resistor and the first temperature sensor, and serves as an input to the PWM controller, a switch whose switching is cut off by the PWM controller in response to the PWM controller determining that the overheating has occurred, and a transformer configured to convert an output alternating current voltage generated according to a switching operation of the switch.