Adaptive Power System Stabilizer for Generator Oscillation Damping
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Solution Overview
Problem
Conventional power system stabilizers are ineffective in damping generator rotor angle oscillations across the entire dynamic operating range due to their fixed, linear parameters, especially with the integration of renewable energy sources that cause frequency fluctuations and reduced synchronous inertia.
Innovation Solution
An adaptive power system stabilizer (PSS) using cascaded estimators to derive dynamic infinite bus values and model generator parameters, incorporating switching logic to adjust models based on sensor inputs, enhancing stability by damping oscillations through an automatic voltage regulator (AVR).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional fixed-parameter PSS is used, then device complexity is reduced, but stability under transient conditions deteriorates
Solution Approach 1:
The patent implements dynamic parameters in the PSS by using cascaded estimators that continuously update infinite bus values and generator parameters based on real-time sensor measurements. The switching logic dynamically selects between different mathematical models (infinite bus model and finite bus model) according to system conditions, allowing the PSS to adapt to transient and steady-state operating conditions effectively.
Solution Approach 2:
The patent employs feedback mechanisms through the cascaded estimator structure where sensor measurements from the power system are continuously fed into the estimators. The first estimator processes measurements to derive infinite bus values, which are then fed into the second estimator to derive generator parameters. These derived parameters are fed back to the PSS controller to adjust stabilization signals, creating a closed-loop feedback system that improves generator stability.
2Measurement precision
If adaptive estimators are implemented, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the estimation function into two distinct cascaded estimators: the first estimator is dedicated to deriving infinite bus values from sensor measurements, while the second estimator derives generator parameters using both sensor measurements and the infinite bus values from the first estimator. This segmentation allows each estimator to specialize in specific parameter derivation, improving measurement precision while organizing the complexity into manageable modular components.
Solution Approach 2:
The first estimator acts as an intermediary between the sensor measurements and the second estimator. It processes the raw sensor data to derive infinite bus values, which then serve as additional inputs to the second estimator for more accurate generator parameter derivation. This intermediary structure improves measurement precision by providing the second estimator with refined intermediate values rather than raw measurements alone.
3Adaptability or versatility
If switching logic is added to adjust models, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent implements parameter changes through switching logic that selects between different mathematical models based on system operating conditions. The switching logic monitors system parameters and changes the model parameters accordingly - using the infinite bus model during normal operation and switching to the finite bus model during transient conditions. This allows the PSS to adapt to varying system conditions while maintaining a relatively simple control structure.
4Reliability
If cascaded estimators are used, then reliability is improved, but device complexity increases
Solution Approach 1:
The cascaded estimator architecture segments the estimation function into specialized components: the first estimator handles infinite bus value derivation while the second estimator handles generator parameter derivation. This segmentation improves reliability by ensuring that each estimator is optimized for its specific function, and the cascaded structure allows error propagation to be minimized since the second estimator uses both sensor measurements and refined infinite bus values from the first estimator.
Data Source
AI summary
A power generation system includes an adaptive power system stabilizer (PSS). The adaptive PSS includes a first estimator configured to receive a plurality of sensor measurements as input and to output a derived infinite bus (TB) value. The adaptive PSS further includes a second estimator disposed downstream of the first estimator and configured to receive the derived IB value as input and to output a derived electric generator parameter, wherein the adaptive PSS is configured to use the derived electric generator parameter to provide stabilization of an electric generator.