Generator Speed Control for Construction Machinery
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Solution Overview
Problem
Construction machinery experiences significant generator speed fluctuations due to sudden changes in engine loads, leading to unpleasant noise and stability issues, which existing nonlinear PID control algorithms and gain scheduling are insufficient to address effectively.
Innovation Solution
A self-adjusting generator speed control system that uses a generator speed controller to compare target and measured generator speed signals, applying adaptive control gain values to reduce speed surging by differentiating between commanded and uncommanded events, with uncommanded event control gain values being reduced stepwise until the generator speed fluctuations meet a predetermined threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If constant control gains are used in nonlinear PID control algorithm, then the control system is simple to implement, but the system cannot effectively respond to various operating scenarios and generator speed surging occurs
Solution Approach 1:
The control system dynamically adjusts control gains based on operating conditions. The processor continuously monitors generator speed and load changes, adapting the control gains in real-time to match current operating scenarios, thereby maintaining stability across varying conditions without requiring complex manual reconfiguration
Solution Approach 2:
The system changes control parameters (gains) based on detected operating conditions. When load changes or speed deviations are detected, the processor modifies the control gains to optimize the control response, enabling the system to handle different operating scenarios effectively while maintaining simplicity in implementation
2Reliability
If gain scheduling is implemented to provide adaptability to different operating scenarios, then the control system becomes more complex, but generator speed surging is still not fully eliminated
Solution Approach 1:
The system employs continuous feedback monitoring of generator speed and load conditions. The processor uses this feedback to detect speed surging and load changes, then adjusts control gains accordingly. This closed-loop feedback mechanism provides effective adaptability while keeping the control algorithm relatively simple by relying on straightforward speed and load measurements
Solution Approach 2:
The control system performs self-adjustment by automatically detecting operating conditions and modifying its own control parameters. The processor monitors generator speed and load changes, then autonomously adjusts the control gains without external intervention, enabling the system to adapt to different scenarios while maintaining algorithmic simplicity
3Reliability
If control gains are reduced to minimize speed surging, then generator speed stability improves, but the system response to load changes becomes slower
Solution Approach 1:
The control gains are made dynamic rather than static. The system uses low control gains during normal operation to minimize speed surging and maintain stability, but automatically increases gains when load changes are detected to maintain fast response. This dynamic adjustment resolves the contradiction by adapting the gain level to the specific operating condition
Solution Approach 2:
The system changes control parameters based on detected conditions. When load changes are detected, the processor temporarily increases control gains to maintain rapid response, then reduces them again once the transition is complete. This parameter adaptation allows the system to achieve both fast response and stability across different operating phases
Data Source
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AI summary
The present invention relates to a generator control system that includes a generator, a variable displacement pump, a generator speed sensor, and a generator speed controller. The generator speed sensor generates a measurement output signal that corresponds to the speed of the generator. The generator speed controller generates a control signal that controls the displacement of the displacement pump to limit generator speed surging. The generator speed controller applying default commanded event control gain values to the control signal when a commanded change in the load or speed of the engine or generator occurs, applying uncommanded event control gain values to the control signal in the absence of a commanded change in load or speed of the engine or generator, and reducing the uncommanded event control gain values as needed until the magnitude of generator speed surging is less than a threshold value or until a minimum uncommanded event control gain value threshold is reached.