Sensorless Torsional Damping via Electrical Torque Estimation
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Solution Overview
Problem
Existing systems for damping torsional vibrations in rotating machinery, particularly in the oil and gas industry, face challenges due to the generation of ripple components by power electronics, which interact with mechanical systems, and require expensive or impractical torque measurements, especially in high-power drive trains and explosive environments.
Innovation Solution
A torsional mode damping controller system that calculates dynamic torque components based on electrical measurements, generates control data to modulate active power, and sends it to converters to damp torsional oscillations without the need for direct mechanical torque sensing, using a controller connected to a converter driving an electrical machine mechanically connected to a train.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque sensors are used to measure mechanical torque for damping control, then damping effectiveness is improved, but system cost and complexity increase significantly
Solution Approach 1:
The patent replaces mechanical torque sensors with an electrical measurement system. The controller measures electrical parameters (current, voltage, frequency) from the power electronics and uses these to calculate torque components and implement damping control. This substitution eliminates the need for mechanical sensors while maintaining damping effectiveness, directly resolving the contradiction between reliability and device complexity.
Solution Approach 2:
The patent introduces electrical parameters as an intermediary between the power electronics and the mechanical system. Instead of directly measuring mechanical torque, the system measures electrical parameters that are coupled to the mechanical torque through the power electronics, and uses these electrical measurements to infer and control the mechanical torque components. This intermediary approach avoids direct mechanical sensing while achieving the same control objective.
2Measurement precision
If torque sensors are installed on shafts, then torsional vibration measurement accuracy is improved, but installation becomes impractical in explosive or inaccessible environments
Solution Approach 1:
The patent replaces mechanical torque sensors that would need to be installed on shafts with an electrical measurement system. The controller obtains electrical parameters from the power electronics circuitry, which are already present in the system. This substitution makes the measurement system easy to install and operate in explosive or inaccessible environments where mechanical sensors would be impractical, while still achieving accurate torque component measurement through electrical parameter analysis.
3Measurement precision
If mechanical torque measurement systems are used, then damping control precision is improved, but system cost increases due to expensive sensors
Solution Approach 1:
The patent replaces expensive mechanical torque sensors with electrical measurement circuitry that is already part of the power electronics system. The controller measures electrical parameters (current, voltage, frequency) using standard electrical sensors and processing, which are significantly less expensive than mechanical torque sensors. This substitution maintains damping control precision while dramatically reducing system cost, directly resolving the contradiction between measurement precision and device complexity.
Data Source
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AI summary
A torsional mode damping controller system is connected to a converter that drives an electrical machine mechanically connected to a train. The controller system includes an input interface configured to receive measured data related to variables of the converter or the electrical machine, and a controller connected to the input interface. The controller calculates at least one dynamic torque component along a section of a shaft of the train based on the data from the input interface, generates control data for the converter for damping a torsional oscillation in the mechanical drive train based on the at least one dynamic torque component, and sends the control data to the converter for modulating an active power exchanged between the converter and the electrical machine.