Material Handler VFD Control for Idle Power and Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Material handlers with constant speed AC electric motors face inefficiencies due to large inrush currents during startup and energy consumption, as well as potential for undesirable vibrations at specific frequencies, which can lead to operator discomfort and equipment wear.
Innovation Solution
A controller configured to provide a variable frequency drive (VFD) signal to the motor, allowing for adjustable frequency based on interface device activity, with the ability to decrease frequency to a standby mode when inactive, reducing power consumption and minimizing undesirable vibrations by skipping specific frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If constant speed AC electric motors are used, then the motor can operate at full power, but large inrush currents occur during startup and energy consumption increases
Solution Approach 1:
The patent applies dynamics by transitioning from constant speed operation to variable speed operation through VFD control. The motor speed is dynamically adjusted based on actual operational needs, allowing the system to operate at lower speeds during standby periods and at full speed when work is required, thereby reducing overall energy consumption while maintaining full power capability when needed.
Solution Approach 2:
The patent changes the operating parameters of the motor by using VFD to vary frequency and voltage. This allows the motor to operate at different speed and power levels depending on demand, reducing energy consumption during low-demand periods while maintaining the ability to deliver full power when required.
2Power
If constant speed AC electric motors are used, then the motor can deliver full power, but undesirable vibrations occur at specific frequencies
Solution Approach 1:
The patent uses dynamic speed adjustment via VFD control to avoid resonant frequencies that cause vibrations. By continuously varying the motor speed, the system can bypass problematic frequency ranges during startup and operation, eliminating vibrations while maintaining full power capability when operating at optimal speeds.
Solution Approach 2:
The patent applies the skipping principle by rapidly transitioning through problematic frequency ranges during motor startup and operation. The VFD controls the motor to skip over resonant frequencies that cause vibrations, allowing the motor to reach operating speed without dwelling in harmful frequency zones, thus eliminating vibrations while maintaining full power output.
3Power
If the motor operates at operating frequency continuously, then full motor performance is maintained, but energy consumption increases during idle periods
Solution Approach 1:
The patent implements dynamic operation modes where the motor transitions between standby frequency (lower power consumption) and operating frequency (full performance) based on controller signals. During idle periods, the motor operates at standby frequency to minimize energy loss, while maintaining the ability to quickly transition to full performance when work is required.
Solution Approach 2:
The patent uses periodic switching between standby and operating modes based on controller detection of interface device activity. The motor alternates between low-power standby operation during idle periods and full-power operation when work is detected, optimizing the balance between performance and energy consumption through periodic mode transitions.
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 reduces energy consumption, minimizes noise and vibrations, and extends equipment lifespan by optimizing motor operation and reducing wear, while maintaining full motor torque at lower amperage levels.
Implementation Method 1
The controller can also be configured to provide a variable frequency drive (VFD) signal to the motor
Data Source
AI summary
A material handler comprises a motor, an interface device, and a controller. The controller is configured to receive an input from the interface device and can include a variable frequency drive (VFD). The controller provides a variable frequency drive (VFD) signal to the motor to control movement of one or more components of the material handler. If the interface device is inactive for a predetermined amount of time, the controller adjusts a frequency of the VFD signal from an operating frequency to a standby frequency with the standby frequency being lower than the operating frequency. Adjusting the frequency from the operating frequency to the standby frequency can include adjusting the frequency of the VFD signal to one or more intermediate frequencies. When adjusting the frequency of the VFD signal, the controller can skip at least one frequency or range of frequencies, for example, to avoid undesirable operating characteristics.