Variable Frequency Drive Vibration Control Using Self-Excited Testing
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Solution Overview
Problem
Current methods for controlling vibrations in variable frequency drive controlled electric machines are inefficient and difficult to implement in operational conditions, requiring specialized personnel and equipment, and are not suitable for real-time monitoring.
Innovation Solution
A method and arrangement that determines resonance frequencies, stiffness, and damping using ramp up/ramp down, impulse, and steady drive tests, and utilizes these parameters to create a vibration control model for effective vibration control, employing a frequency converter and vibration sensors to measure and analyze data for continuous vibration control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional modal analysis hammer kits are used to determine vibration characteristics, then measurement precision is improved, but device complexity and ease of operation deteriorate due to requiring specialized personnel and equipment
Solution Approach 1:
The patent replaces the mechanical hammer impact system with an electromagnetic excitation system. The frequency converter generates controlled voltage signals that create electromagnetic forces to excite the motor, eliminating the need for physical impact hammers and complex modal analysis equipment while achieving accurate vibration characteristic measurement.
Solution Approach 2:
The motor itself serves as both the test object and the excitation source. By utilizing the motor's own electromagnetic structure and applying controlled voltage through the frequency converter, the system performs self-testing without requiring external impact equipment or specialized personnel, simplifying the overall testing process.
2Measurement precision
If traditional modal analysis methods are used, then vibration characteristics can be determined, but ease of operation and productivity deteriorate due to difficulty in implementation during operational conditions
Solution Approach 1:
The system performs vibration characteristic measurement during the motor's normal operational startup and shutdown phases. By utilizing these transitional periods when the motor is already connected to the frequency converter, the method collects necessary data without requiring separate dedicated testing sessions or interrupting normal operations.
Solution Approach 2:
The frequency converter serves multiple functions: it controls the motor during normal operation and simultaneously acts as the excitation source for vibration measurement. This multi-functionality eliminates the need for separate testing equipment and allows operational condition testing to proceed seamlessly.
3Reliability
If comprehensive vibration testing is performed to identify all resonance frequencies and mechanical properties, then reliability is improved, but loss of time increases due to multiple test requirements
Solution Approach 1:
The system continuously measures vibration characteristics throughout the motor's acceleration and deceleration phases. By maintaining continuous measurement during these natural operational transitions, the method captures all necessary resonance frequencies and damping information in a single uninterrupted process, eliminating the need for multiple separate tests at different operating points.
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
This approach allows for efficient and easier vibration control of electric machines in operational conditions, reducing harmful vibrations and enabling predictive maintenance by identifying mechanical properties and controlling vibrations effectively.
Implementation Method 1
a first voltage signal at a first frequency is generated by a frequency converter, wherein the first voltage signal causes the electric machine to vibrate at a first vibration frequency
Implementation Method 2
a first vibration signal at the first vibration frequency is measured by a vibration sensor
Data Source
AI summary
A field of electric drive devices and electric machines, such as electric motors and electric generators for industrial applications and more particularly to a method and an arrangement for controlling vibration of a variable frequency drive controlled electric machine. In the method for controlling vibration of a variable frequency drive controlled electric machine, the resonance frequency/frequencies and the stiffness are determined in a ramp up/ramp down test; amount of damping is determined in an impulse test; a mechanical transfer function is determined in a steady drive test; a vibration control model is determined utilizing said resonance frequency/frequencies, said stiffness, the amount of damping and the mechanical transfer function; and vibration is controlled utilizing the vibration control model.