Electric Machine Shaft Damping for Compressor Surge Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Compression systems, such as rotating compressors and pumps, face flow instabilities like surge and rotating stall, which can damage components and reduce efficiency, and existing active surge control methods add weight and penalize efficiency.
Innovation Solution
An electric machine coupled with the compression system via a shaft system is controlled to adjust parameters like torque and speed to dampen instability fluctuations, reducing the need for variable geometry components and enhancing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active surge control components (recycle valves, bleed valves, variable guide vanes) are added to the compression system, then surge and rotating stall are controlled effectively, but device complexity and weight increase
Solution Approach 1:
The electric machine is designed to serve multiple functions: it acts as both a generator for power production and a control actuator for surge suppression. By modulating the electrical load on the generator, the system can rapidly adjust compressor shaft power to prevent surge and rotating stall, eliminating the need for separate dedicated surge control components like recycle valves or variable guide vanes.
Solution Approach 2:
The invention extracts the surge control function from separate mechanical components and integrates it into the electric machine control system. By removing dedicated surge control hardware and using only the electric machine's electrical load modulation capability, the system reduces device complexity while maintaining surge control effectiveness.
2Reliability
If traditional surge avoidance controls are used to keep the operating point away from the surge line, then surge is prevented, but the operating range of the compression system is restricted and efficiency is limited
Solution Approach 1:
The system employs active feedback control where sensors monitor compressor operating conditions (pressure, flow, vibration) and the controller continuously adjusts the electrical load on the generator in real-time. This closed-loop control enables the system to operate closer to the surge line by rapidly responding to incipient surge conditions, thereby expanding the usable operating range while maintaining surge prevention.
Solution Approach 2:
The invention transitions from static surge avoidance (fixed safety margins) to dynamic surge control. The electric machine's electrical load can be modulated rapidly and precisely to actively suppress surge oscillations as they develop, allowing the system to operate dynamically near the surge line rather than requiring fixed conservative operating margins.
3Stability of the object's composition
If variable geometry components are added to control surge and rotating stall, then flow stability is improved, but weight and device complexity increase
Solution Approach 1:
The invention replaces mechanical variable geometry control systems (which require moving parts, actuators, and complex linkages) with an electrical control system. By modulating the electrical load on the generator, the system achieves flow stability control through power adjustment rather than mechanical geometry changes, significantly reducing weight and complexity.
4Reliability
If recycle or bleed valves are used for active surge control, then surge oscillations are dampened, but efficiency is penalized due to flow losses
Solution Approach 1:
The invention extracts the surge control function from flow-altering mechanical components (recycle/bleed valves) and implements it through electrical load modulation. This approach dampens surge oscillations by adjusting power demand rather than by creating flow losses through valve restrictions or recirculation paths, thereby maintaining system efficiency.
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 more efficient operation closer to the stall line, reducing the stall margin and eliminating the need for additional components, thereby improving mechanical power extraction and reducing fuel flow.
Implementation Method 1
dampen instability fluctuations
Data Source
AI summary
The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.