Motor Control Device Voltage Surge Elimination
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Solution Overview
Problem
Existing motor control systems for wiper apparatuses face challenges in eliminating voltage surges while minimizing torque changes in the output shaft, leading to potential damage and user-noticeable vibrations.
Innovation Solution
A motor control device and program that utilize a driving unit to supply voltage in alternating directions and a control unit to manage voltage drop, employing switching elements and freewheel diodes to eliminate counter electromotive force currents, thereby reducing torque changes and protecting the circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Zener diodes are added to eliminate voltage surges, then circuit protection is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts the surge elimination function from passive components (Zener diodes) and implements it through active control of existing motor control circuits. The control unit detects voltage surges and activates specific switching elements to create discharge paths for surge current, eliminating the need for additional protective components and reducing manufacturing cost while maintaining circuit protection.
Solution Approach 2:
The patent makes the motor control circuit serve multiple functions: it not only controls motor operation but also detects voltage surges and eliminates them through controlled discharge paths. The switching elements and control unit are reused for both motor control and surge protection, avoiding the need for separate protective components and reducing overall system cost.
2Reliability
If the motor is used to eliminate surges by rotating forward and backward, then voltage surge protection is improved, but torque ripple and vibration increase
Solution Approach 1:
The patent segments the surge elimination process into distinct phases: detection phase, discharge path activation phase, and motor control phase. By separating the surge discharge function from motor rotation, the system can eliminate surges through controlled current paths without necessarily activating motor rotation, thereby reducing torque ripple and vibration while maintaining voltage surge protection.
Solution Approach 2:
The patent introduces switching elements as intermediaries between the voltage surge and the motor. These switching elements create controlled discharge paths that divert surge current away from the motor winding, allowing surge elimination without requiring the motor to rotate forward and backward, thus reducing harmful torque ripple and vibration.
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 eliminates voltage surges while suppressing torque changes in the motor output shaft, reducing the risk of circuit damage and user-perceptible vibrations, without the need for expensive high-voltage Zener diodes.
Implementation Method 1
the phenomenon of counter electromotive force in which the current having a polarity opposite to that of energization to the motor M is generated is observed at the dead time St12 and the dead time St14
Data Source
AI summary
A motor control device includes: a driving unit that supplies a driving voltage to a motor so as to rotate the motor in a predetermined direction and in a direction opposite to the predetermined direction; a voltage detection unit that detects a voltage of a circuit including the driving unit; and a control unit that has the driving unit execute a voltage drop control that lowers a voltage of the circuit by supplying the driving voltage to the motor and stopping the supply of the driving voltage in a predetermined manner, in a case in which a voltage that is equal to or higher than a threshold voltage is detected by the voltage detection unit in a state in which the motor is not being driven.