Generator Cooling Dynamic Temperature Control
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Solution Overview
Problem
The static control of cold gas temperature in generator cooling circuits leads to over-dimensioned cooling during low load and startup/shutdown operations, causing thermomechanical stresses due to frequent load changes and varying thermal expansion coefficients, accelerating the ageing of generator components.
Innovation Solution
A method that dynamically adjusts cold gas temperature setpoints based on stator and rotor currents, controlling the cooling liquid flow to match the generator's operating state, with redundant temperature detection and optional heating to maintain a safe temperature margin and reduce thermomechanical stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If static control of cold gas temperature is used, then the generator is cooled adequately during base load operation, but the generator is over-cooled during low load and partial load operation causing thermomechanical stresses
Solution Approach 1:
The patent applies dynamic control by continuously adjusting the cold gas temperature setpoint based on the actual operating mode (base load, medium load, low load, startup, shutdown, turning operation) rather than using a fixed static temperature. This dynamic adaptation prevents over-cooling during variable load operations while maintaining adequate cooling during base load, thereby reducing thermomechanical stresses and extending component lifespan
Solution Approach 2:
The patent changes the temperature parameter dynamically by defining different cold gas temperature setpoints corresponding to different operating modes. The control system selects appropriate temperature setpoints based on operating conditions, allowing the temperature to vary within defined ranges rather than remaining constant, thus avoiding excessive cooling during low load operations
2Power
If constant cooling liquid flow is used, then the cooling capacity is sufficient during high load operation, but the cooling is excessive during low load and startup/shutdown processes
Solution Approach 1:
The patent implements dynamic adjustment of cooling liquid volumetric flow based on the generator's operating mode. During base load operation, higher flow rates provide sufficient cooling capacity, while during low load, partial load, startup, shutdown, and turning operations, the flow rate is reduced to match the lower cooling demand, thereby avoiding energy waste through over-cooling
Solution Approach 2:
The patent changes the cooling liquid flow parameter dynamically by establishing different volumetric flow ranges for different operating modes. The control system adjusts the flow parameter according to the detected operating condition, optimizing the balance between cooling capacity and energy consumption across varying load conditions
3Adaptability or versatility
If frequent load changes occur, then the generator responds to grid demands from volatile power sources, but thermomechanical stresses increase due to thermal expansion variations
Solution Approach 1:
The patent applies dynamic temperature control that adapts to frequent load changes by selecting appropriate temperature setpoints for each operating mode. During transitions between operating modes (e.g., from base load to low load), the temperature setpoint changes dynamically, reducing thermal gradients and expansion variations, thereby minimizing thermomechanical stresses while maintaining adaptability to grid demand changes
Solution Approach 2:
The patent changes the temperature parameter in response to operating mode transitions caused by frequent load changes. By defining temperature ranges for different operating conditions and dynamically selecting the appropriate range, the system accommodates load variations while maintaining more uniform thermal conditions, thus reducing thermomechanical stresses on generator components
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 ensures a more uniform temperature level within the generator, reducing thermomechanical stresses and maintaining sufficient cooling capacity while preventing overheating, thus extending the lifespan of generator components.
Implementation Method 1
a cooler (3) through which flows a cooling liquid
Data Source
AI summary
Provided is a method for controlling the cold gas temperature of a cooling gas of a closed generator cooling gas circuit of a generator having at least one cooler through which a cooling fluid flows. The method includes: a) defining cold gas temperature setpoint values in dependence on the stator and rotor current of the generator; b) detecting the current cold gas temperature; c) detecting the current stator and rotor current; d) determining the cold gas temperature setpoint value associated with the stator and rotor current detected in step c); e) regulating the cold gas temperature by changing the volumetric flow of the cooling fluid supplied to the at least one cooler as a function of the difference between the current cold gas temperature detected in step b) and the cold gas temperature setpoint value determined in step d); and f) repeating steps b) to e) at defined time intervals.