Inverter Torque Damping for Electric Machine Rotor Oscillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for mitigating mechanical oscillation in electric machines, such as traction drive electric motors in vehicles, face challenges with analog filters that are not field-tunable and require specialized resources, while digital filters struggle with practical tuning and adjustment across different vehicles and environments.
Innovation Solution
An inverter system with a torque command generation module, a torque damping module featuring a digital filter of order greater than one, a gain adjuster, and a limiter, which detects commanded torque and rotational speed to generate compensating torque, effectively damping mechanical oscillations by isolating oscillations and adjusting gains within defined limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If analog filters are used to reduce mechanical oscillation, then oscillation damping is improved, but field tunability and adaptability deteriorate
Solution Approach 1:
The patent replaces analog mechanical/electrical filter systems with a digital filter implementation in the motor controller. The digital filter uses software-based signal processing to achieve oscillation damping while maintaining field tunability through programmable parameters. This substitution allows the system to be reconfigured for different vehicles and environments without hardware changes.
Solution Approach 2:
The patent implements可调 digital filter parameters that can be modified through software updates or configuration. The filter characteristics (such as cutoff frequency, order, and coefficients) can be changed to adapt to different mechanical loads, vehicle types, and operating conditions, providing both effective oscillation damping and field adaptability.
2Reliability
If analog filters are used to reduce mechanical oscillation, then oscillation damping is improved, but device complexity and specialized resources required deteriorate
Solution Approach 1:
The patent merges the oscillation damping function with the existing motor control software architecture. The digital filter is integrated into the torque command generation module, combining multiple functions (torque control, oscillation damping, and adaptive tuning) into a unified software-based control system, thereby reducing overall device complexity.
Solution Approach 2:
The digital filter implementation utilizes the existing computational resources of the motor controller's digital signal processor or microcontroller. The system serves itself by using its own processing capabilities to perform filtering operations, eliminating the need for separate dedicated filter hardware and reducing overall system complexity.
3Adaptability or versatility
If digital filters are used for torque damping, then field tunability is improved, but practical tuning efficiency and ease of operation deteriorate
Solution Approach 1:
The patent implements a feedback mechanism where the motor controller monitors mechanical oscillation characteristics in real-time and automatically adjusts digital filter parameters to optimize damping performance. This closed-loop approach eliminates the need for manual tuning by operators, improving both ease of operation and tuning efficiency while maintaining field adaptability.
Solution Approach 2:
The digital filter system performs self-tuning by automatically adapting its parameters based on observed oscillation patterns and operating conditions. The controller autonomously optimizes filter characteristics without requiring external intervention or specialized tuning procedures, making the system easy to operate across different vehicles and environments.
Data Source
AI summary
An inverter system is configured to mitigate oscillation of a rotary system that drives a generator or electric machine. A torque damping module is configured to receive a commanded torque or an observed torque and to generate a commanded compensating torque to dampen any mechanical oscillation or resonance of the rotary system based on the observed rotational speed of the generator. The torque damping module further comprises a digital filter of order greater than one, a gain adjuster and a limiter.