Wind Turbine Phase-Locked Loop Parameter Adaptation
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Solution Overview
Problem
Wind energy installations face challenges in maintaining reliable and dynamic phase angle tracking during transient voltage faults in the electrical supply network, leading to erratic behavior and instability during voltage dips.
Innovation Solution
A method that adjusts the phase-locked loop parameters based on measured voltage amplitude, allowing the phase-locked loop to adapt its dynamics during voltage drops without compromising control dynamics, ensuring the wind energy installation remains connected to the grid even during zero voltage ride-through conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the phase-locked loop uses fixed parameters for synchronization, then the control dynamics are optimized for nominal operation, but the system exhibits erratic behavior during voltage dips
Solution Approach 1:
The patent applies dynamics by making the phase-locked loop parameters adjustable rather than fixed. The controller adapts the parameters of the phase-locked loop based on detected voltage conditions, switching between different parameter sets for nominal operation and voltage dip conditions. This allows the system to dynamically respond to changing grid conditions while maintaining reliable synchronization.
2Speed
If the phase-locked loop parameters are adjusted for high dynamics during nominal operation, then the power feed-in response is fast, but the system becomes unstable during voltage dips
Solution Approach 1:
The patent implements parameter changes by modifying the phase-locked loop parameters based on voltage amplitude detection. When a voltage dip is detected, the controller changes the parameters to a second set optimized for stability during faults. When nominal voltage is restored, the parameters are changed back to the first set for high dynamic response. This parameter adaptation resolves the contradiction between speed and stability.
3Reliability
If the wind energy installation disconnects during voltage dips to avoid erratic behavior, then system stability is maintained, but continuous power feed-in is interrupted
Solution Approach 1:
The patent converts the harmful effect of voltage dips into a beneficial outcome by using the voltage amplitude information not only for protection but also for adaptive control. By detecting the voltage dip and adjusting the phase-locked loop parameters accordingly, the system maintains stable operation and continuous power feed-in during conditions that would traditionally cause disconnection. The harmful voltage fault becomes an input signal for adaptive parameter adjustment.
Data Source
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AI summary
Method for operating a wind turbine which feeds electrical power into an electrical supply network via a converter, synchronized to a grid voltage, wherein the method comprises the following steps: - measuring a phase angle and a voltage in the electrical supply network, - determining the value of at least one parameter for a phase-locked loop (PLL) depending on the measured voltage, - setting the at least one parameter on the phase-locked loop, - determining a controlled phase angle using the set phase-locked loop (PLL) depending on the measured phase angle from the electrical supply network, and - controlling the converter with the controlled phase angle.