Motor Drive Control Device for Overcurrent Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor drive control systems face challenges in quickly stopping motors while preventing overcurrents that can cause burnout or damage when power supply is unexpectedly stopped, and the use of backup power supplies complicates the system and increases costs.
Innovation Solution
A drive control device that includes an inverter circuit, a capacitor, a diode, a rectifier circuit, a photo coupler, a switch circuit, and a voltage detector, which converts direct current voltage to alternating current and uses a threshold-based control mechanism to prevent overcurrents by short-circuiting motor coils only when necessary to stop the motor quickly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the motor is stopped quickly by short-circuiting the coils, then the stopping time is reduced, but overcurrents are generated that can cause burnout or damage
Solution Approach 1:
The capacitor is charged in advance during normal operation before power failure occurs. When power is lost, the pre-charged capacitor immediately provides the voltage needed to drive the switching element and short-circuit the motor coils, enabling quick stopping without waiting for external power recovery.
Solution Approach 2:
The switching element acts as an intermediary controlled by the control circuit. It selectively connects the motor coils to either the DC voltage source during normal operation or to ground for braking when power fails. This intermediary control prevents direct uncontrolled short-circuiting that would cause damaging overcurrents.
Solution Approach 3:
The system changes the voltage parameter dynamically - maintaining normal DC voltage during operation, then switching to capacitor-driven voltage during power failure, and finally to ground potential during braking. The control circuit monitors voltage parameters to determine when to activate braking mode.
2Reliability
If a backup power supply is used to control braking during power failure, then the motor can be stopped safely, but the system complexity and cost increase
Solution Approach 1:
The capacitor serves itself by being charged from the normal power supply during operation and then autonomously providing the necessary voltage during power failure without requiring external backup power sources. The system uses its own operational power to prepare the energy storage element for emergency braking.
Solution Approach 2:
The system recovers and stores energy in the capacitor during normal operation, then discards the need for complex backup power supplies by using this stored energy for braking control during power failure. The capacitor replaces the function of dedicated backup power circuits.
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 overcurrents and prevents burnout or damage by controlling the motor's braking based on the number of revolutions, allowing for quick and safe motor stoppage without the need for complex backup power supplies.
Implementation Method 1
The inverter circuit converts a direct current voltage into an alternating current voltage, and supplies the alternating current voltage to the motor
Implementation Method 2
The rectifier circuit rectifies an induced voltage, which is generated in the motor, and outputs a rectified voltage
Implementation Method 3
The photo coupler converts the rectified voltage into an optical signal, and thereafter, converts the optical signal into a converted signal
Data Source
AI summary
A drive control device for a motor includes an input terminal, an output terminal, an inverter circuit, a first switch unit, a capacitor, a diode, a rectifier circuit, a photo coupler, a second switch unit, and a voltage detector. The inverter circuit converts a direct current voltage into an alternating current voltage, and outputs the alternating current voltage to the output terminal. The first switch unit shorts the output terminal based on a control signal. The capacitor is connected to the input terminal, and is charged by a direct current voltage. The diode is connected between the input terminal and the capacitor. The diode limits a direction where a charge current for charging the capacitor flows. The rectifier circuit rectifies an induced voltage, which is generated in the motor, and outputs a rectified voltage. The photo coupler converts the rectified voltage into an optical signal, and thereafter, converts the optical signal into a converted signal. The second switch unit outputs the control signal based on the converted signal. The voltage detector detects whether the direct current voltage is input to the input terminal, and determines whether to negate the control signal.