Motor Control Apparatus Temperature Estimation Overheat Protection
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Solution Overview
Problem
Conventional motor control apparatuses for electric motors often forcibly stop operations due to overheating, leading to incomplete continuous tasks like window glass closure, which can result in the glass being stuck at a middle position and potentially causing pinching hazards.
Innovation Solution
A motor control apparatus that estimates the operational temperature of the electric motor and disables or enables its operation based on predetermined temperature ranges, allowing continuous operation completion without the need for bulky protective devices, thereby preventing overheating and pinching incidents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protective devices such as bimetal or PTC device are integrated into the motor, then the motor can be protected from overheating and burnt, but the motor size increases
Solution Approach 1:
The patent replaces mechanical protective devices (bimetal, PTC) with an electronic temperature estimation system. The control unit calculates estimated motor temperature based on energizing voltage and time, then controls motor operation accordingly. This substitutes physical protective components with an electronic control mechanism, reducing motor size while maintaining protection capability.
2Reliability
If the motor control apparatus forcibly stops operation when estimated temperature exceeds overheat prevention temperature, then the motor is protected from overheating, but continuous set operations such as window glass closure are interrupted
Solution Approach 1:
The patent introduces dynamic control of the overheat prevention temperature threshold based on operational context. When a continuous set operation is detected, the control unit allows the motor to operate even if the estimated temperature exceeds the normal overheat prevention temperature, completing the set operation first. This dynamic adjustment resolves the contradiction between immediate protection and task completion.
Solution Approach 2:
The control unit performs preliminary detection of continuous set operations and prepares to adjust temperature thresholds in advance. By identifying when a continuous set operation is in progress before temperature issues arise, the system can proactively allow higher temperatures during these operations, preventing unnecessary interruptions.
3Reliability
If the motor is forcedly stopped during automatic closing operation, then overheat protection is activated, but the window glass stops at middle position creating pinching hazard
Solution Approach 1:
The patent dynamically adjusts the overheat prevention temperature threshold based on the operational state. During automatic closing operations, the control unit raises or suspends the temperature threshold, allowing the motor to continue operating even at higher temperatures. This ensures the window glass completes its closure journey without forced stopping, eliminating the pinching hazard while maintaining motor protection through post-operation temperature monitoring.
Data Source
AI summary
A motor control apparatus for controlling an operation of an electric motor has an operational temperature estimator and an operation controller. The operational temperature estimator estimates an estimated temperature of the electric motor. The operation controller disables to start the operation of the electric motor while the estimated temperature is within a predetermined operation start disable range, and enables to continue the operation of the electric motor when the estimated temperature increases into the operation start disable range.