DFIG Active Damping Control for Sub-Synchronous Oscillation
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Solution Overview
Problem
Existing control strategies for sub-synchronous oscillation in DFIG wind farms are limited to specific oscillation frequency points and fail to effectively damp oscillations across changing scenarios, particularly neglecting super-synchronous and fundamental frequency bands, leading to control blind spots and reduced accuracy and efficiency.
Innovation Solution
An active damping control method and system that collects stator current and voltage oscillations to determine energy branches and their functions, implementing energy compensation branches to control sub-synchronous oscillations, optimizing parameters for stability across sub-synchronous and super-synchronous frequency bands using stability coefficient ratios as objective functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing control strategies are used for sub-synchronous oscillation, then control is achieved at specific frequency points, but control accuracy deteriorates when oscillation frequency changes due to system operation mode changes
Solution Approach 1:
The patent transforms the static control approach into a dynamic one by continuously tracking oscillation frequency and adapting control parameters in real-time. The control strategy dynamically adjusts to frequency changes caused by system operation mode variations, ensuring sustained control accuracy across changing scenarios through real-time frequency estimation and parameter adaptation.
Solution Approach 2:
The patent changes control parameters based on detected oscillation frequency and system operation mode. By continuously monitoring frequency variations and adjusting control parameters accordingly, the system maintains effective suppression across different frequency points and operating conditions, resolving the contradiction between fixed-point control and frequency adaptability.
2Reliability
If existing control strategies focus on sub-synchronous frequency band, then sub-synchronous stability is improved, but control blind spots occur in super-synchronous and fundamental frequency bands
Solution Approach 1:
The patent extends the control strategy to cover multiple frequency bands simultaneously - sub-synchronous, fundamental, and super-synchronous. By designing a universal control approach that addresses all three frequency bands, the system eliminates control blind spots while maintaining sub-synchronous stability, achieving comprehensive oscillation suppression across the entire frequency spectrum.
3Reliability
If existing control strategies are applied, then sub-synchronous oscillation suppression is achieved, but control efficiency decreases due to control blind spots and limited frequency coverage
Solution Approach 1:
The patent implements dynamic frequency tracking and adaptive control parameter adjustment that responds to real-time oscillation characteristics. This dynamic approach eliminates control blind spots and ensures continuous effective suppression across all frequency bands, significantly improving control efficiency while maintaining reliable oscillation suppression performance.
Data Source
AI summary
The disclosure relates to an active damping control method and system for sub-synchronous oscillation of DFIG, and storage medium. The method comprises the following steps: collecting oscillation components of stator current and/or stator voltage; determining each energy branch in DFIG converter according to the flow path of the oscillation component(s) of the stator current and/or the stator voltage in DFIG converter; determining the corresponding function of each energy branch according to oscillation component(s) the stator current and/or the stator voltage; determining the energy compensation branch and its corresponding energy compensation function in DFIG converter according to the corresponding function of each energy branch and converter parameters; controlling the sub-synchronous oscillation of DFIG by controlling the energy compensation branch according to the energy compensation function.