Wind Turbine Filter Choke Saturation for Harmonic Damping
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Solution Overview
Problem
Traditional wind energy installations require large and expensive filter devices to counteract harmonics in generator currents, which often lead to resonance issues and heat-related problems due to the use of damping resistors, resulting in inefficiencies and increased costs.
Innovation Solution
A wind energy installation with a filter device that uses choke coils with a saturation current value below the rated filter current, allowing for inductive behavior at lower currents and ohmic behavior at higher currents, eliminating the need for damping resistors and reducing the filter device's size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional filter devices with large filter chokes are used, then harmonics are reduced, but the device size and weight increase significantly
Solution Approach 1:
The patent applies dynamic principle by making the filter choke inductance variable through magnetic saturation control. The choke coil transitions from unsaturated (high inductance) to saturated (low inductance) state based on current magnitude, enabling the filter device to adapt its characteristics dynamically rather than maintaining fixed large inductance throughout operation
Solution Approach 2:
The patent changes the inductance parameter of the filter choke by controlling the magnetic saturation state. By designing the choke coil with specific saturation current characteristics, the inductance automatically adjusts from high values (when unsaturated) to low values (when saturated), reducing the required size and weight of the filter device while maintaining harmonic filtering effectiveness
2Object-generated harmful factors
If traditional filter devices with large filter chokes are used, then harmonics are reduced, but the device cost increases
Solution Approach 1:
The dynamic magnetic saturation characteristic allows the filter device to achieve effective harmonic filtering only when needed (during high current operation), reducing the required choke size and associated costs for materials, manufacturing, and installation
Solution Approach 2:
By changing the inductance parameter through saturation control, the patent enables a smaller, less expensive choke design that still provides adequate filtering performance, reducing overall device cost while maintaining functionality
3Stability of the object's composition
If damping resistors are used in traditional filter devices, then resonance is controlled, but power losses increase and active cooling is required
Solution Approach 1:
The magnetic saturation characteristic provides dynamic damping without resistors. During high current operation, the choke enters saturation, naturally reducing inductance and damping resonance. During low current operation, the choke remains unsaturated with high inductance, providing filtering without the continuous power losses associated with resistor-based damping
Solution Approach 2:
The patent replaces the mechanical/thermal damping system (resistors with active cooling) with a magnetic field-based damping mechanism. The magnetic saturation effect provides the necessary damping action through electromagnetic principles rather than resistive heating, eliminating the need for continuous power dissipation and active cooling systems
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 design reduces electrical oscillations, shifts the resonance point to higher frequency ranges, and eliminates the need for active cooling, resulting in a more compact, economical, and efficient filter device with reduced power losses and component count.
Implementation Method 1
at least one inductor coil connected in series upstream of the capacitance for generating a filter current (I F ) for influencing the generator current
Implementation Method 2
the choke coil having a saturation current value which designates an amplitude of the filter current at which the choke coil has a magnetic saturation state
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
The invention relates to a wind turbine (100) for generating electric power for feeding into an electric supply grid, comprising a multiphase generator (200), in particular a synchronous generator, for generating electric power. The generator generates a multiphase generator current (IG1, IG2, IG3), and the generator has a generator output (201) for outputting the multiphase generator current. The wind turbine also comprises a filter device (204, 206) connected to the generator output for generating a filter current (IF) in order to influence the generator current, in particular in order to reduce electric oscillations of the generator current, wherein the generated filter current depends on the generated power of the generator, and the filter device comprises at least one capacitor (208) for influencing the filter current, and at least one choke coil (210) which is serially connected upstream of the capacitor for influencing the filter current. The choke coil has a saturation current value that indicates the filter current amplitude at which the choke coil is in a magnetic saturation state, said saturation current value lying below a specified filter nominal current of the filter device.