Drive System Torque Control for Torsional Oscillation Damping
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Solution Overview
Problem
Complex drive systems experience unwanted torsional oscillations due to torsional flexibility of shafts and rotating components, and existing methods require individual design-based solutions for damping these oscillations.
Innovation Solution
A method involving a multi-inertia model of the drive system, where angular speeds are measured and modeled to determine damping torques using a damping matrix, which is adapted to the system's structural design, allowing for versatile damping of torsional oscillations across multiple electrical machines and rotating components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple damping method is used, then the device complexity is reduced, but it cannot effectively handle complex drive systems with multiple electrical machines and rotating components
Solution Approach 1:
The patent develops a universal damping control method that can be applied to various complex drive systems with multiple electrical machines and rotating components. The method uses a standardized state-space model and damping torque calculation approach that works across different system configurations, making the solution multi-functional and broadly applicable rather than system-specific
Solution Approach 2:
The patent transforms the physical drive system into a mathematical state-space representation with state variables, system matrices, and damping parameters. By changing the representation from physical components to mathematical parameters, the complex physical system becomes manageable through parameter-based control while maintaining accuracy
2Reliability
If individual design-based solutions are used for each drive system, then the damping effectiveness is improved, but the device complexity and design time increase
Solution Approach 1:
The patent segments the complex drive system into discrete inertia elements connected by coupling elements, each representing specific physical components. This segmentation allows the system to be analyzed and controlled through modular state-space equations, maintaining damping effectiveness while reducing overall design complexity through systematic decomposition
Solution Approach 2:
The patent implements a feedback mechanism where the state variables (angular speeds and torques) are continuously monitored and fed back into the damping torque calculation. This feedback loop ensures effective damping by continuously adjusting the control torque based on current system state, while the standardized feedback structure reduces design complexity compared to ad-hoc solutions
3Measurement precision
If comprehensive measurements of all shafts are taken, then the measurement precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent introduces a mathematical model as an intermediary between the physical system and the measurements. The state-space model allows angular speeds of unmeasured shafts to be calculated from measured speeds through the system's dynamic relationships, acting as a mediator that provides comprehensive information without requiring comprehensive sensors
Solution Approach 2:
The patent creates a mathematical copy (state-space model) of the physical drive system that replicates its dynamic behavior. This virtual model allows the system to infer unmeasured states from measured ones, providing the benefit of comprehensive measurement precision without the cost and complexity of physical sensors on every component
Data Source
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AI summary
A drive system (10) comprises at least one electrical machine (12) and a plurality of rotating components (14), which are interconnected via shafts (18, 20, 22). A method for damping torsional oscillations in the drive system (10) comprises: determining angular speeds (θi) for at least one of the shafts (18) based on measurements in the drive system (10); determining a damping torque (Tdamp) from the angular speeds (θi) with a function that models at least some of the electrical machine (12), the rotating components (14) and the shafts (18, 20, 22); adapting a reference torque (Tref) for the at least one electrical machine (12) by adding the damping torque; and controlling the at least one electrical machine (12) with the adapted reference torques (T).