Motor Switch Thermal Control for Abnormal Current Conditions
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Solution Overview
Problem
Existing motor control devices separate from the motor cannot effectively suppress temperature rises in motors during abnormal conditions, such as increased current flow, as they rely on direct temperature detection which is not feasible and leads to repeated temperature fluctuations, potentially causing the motor temperature to exceed safe limits.
Innovation Solution
A motor control device with a switch and temperature detection unit in the electrical conduction path, which controls the switch between on and off states based on detected temperature thresholds, switching to a lower overheat detection threshold and reducing electrical conduction to manage heat generation during abnormal conditions, thereby suppressing motor temperature rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the motor control device forcibly turns off the switch when temperature exceeds the overheat detection threshold value, then the switch temperature is controlled, but the motor temperature may continue to rise and exceed safe limits
Solution Approach 1:
The patent applies dynamics by making the overheat detection threshold value changeable based on operating conditions. The control unit switches between a first overheat detection threshold value (higher) and a second overheat detection threshold value (lower) depending on whether the motor is in normal operation or abnormal conditions. This dynamic adjustment allows the system to respond appropriately to different scenarios: using the higher threshold during normal operation to avoid unnecessary shutdowns, and switching to the lower threshold during abnormalities to prevent motor overheating by triggering earlier shutdowns.
2Temperature
If the switch is repeatedly turned on and off due to temperature fluctuations, then the switch temperature is managed, but the motor operation is interrupted and productivity decreases
Solution Approach 1:
The patent uses dynamic threshold adjustment to balance temperature control and operational continuity. By switching between a higher first threshold and a lower second threshold based on abnormality detection, the system avoids repeated on-off cycling during normal conditions (maintaining productivity) while ensuring adequate protection during abnormal conditions (managing temperature).
Solution Approach 2:
The patent changes the parameter of the overheat detection threshold value based on system state. The control unit monitors for abnormal conditions and adjusts the threshold parameter accordingly - using a higher value during normal operation to maintain continuity and a lower value during abnormalities to ensure temperature control. This parameter change resolves the contradiction by adapting the detection criterion to the operating context.
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 effectively suppresses motor temperature rises by continuing motor operation while reducing electrical conduction, shortening overheating detection times and minimizing heat generation, thus preventing motor temperature from exceeding safe limits.
Implementation Method 1
The motor control device detects a temperature of the switch
Implementation Method 2
switching to a lower overheat detection threshold and reducing electrical conduction to manage heat generation during abnormal conditions
Data Source
AI summary
A motor control device controls a motor. The motor control device is provided separate from the motor. The motor control device includes a switch provided in an electrical conduction path for the motor. The motor control device detects a temperature of the switch. The motor control device controls the switch between an on state and an off state.