Wind Turbine Pitch Control System Grid Transient Protection
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Solution Overview
Problem
Existing wind turbine pitch control systems are vulnerable to high voltage transients from the electric utility grid, which can damage components and are inefficient due to shared current in DC motors, leading to energy losses and increased complexity.
Innovation Solution
A pitch control system with a motor having separate armature and winding currents, utilizing switching components to independently control these currents and an auxiliary switching component to disconnect from the grid during high voltage transients, preventing component damage and allowing reconnection when voltage returns to a safe threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a series field winding DC motor is used in the pitch control system, then the motor can be controlled to adjust blade pitch, but the armature and winding share a common current which prevents independent control and causes energy losses
Solution Approach 1:
The patent segments the current control by introducing a current splitter that divides the input current into two independent controllable paths: one for the armature and one for the field winding. This allows independent control of both currents while maintaining a single input current source, resolving the contradiction between independent control capability and device complexity.
2Adaptability or versatility
If dynamic braking resistors and rectification diodes are added to the pitch control system, then motor braking and reverse rotation are enabled, but system cost and complexity increase
Solution Approach 1:
The patent makes the switching components universal by designing them to perform multiple functions: they control current distribution to the armature and field winding during normal operation, and also enable braking and reverse rotation functions. This eliminates the need for separate dynamic braking resistors and rectification diodes, reducing component quantity while maintaining operational flexibility.
3Reliability
If the pitch control system remains connected to the electric utility grid, then continuous power supply is maintained, but high voltage transients can damage components
Solution Approach 1:
The patent introduces an auxiliary switching component as an intermediary between the grid and the pitch control system. This component monitors grid voltage and automatically disconnects the system during high voltage transients, protecting components from damage. The component acts as a mediator that allows continuous operation under normal conditions while providing protection during abnormal conditions, maintaining both reliability and productivity.
Data Source
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AI summary
A pitch control system 30 for a wind turbine 10 is disclosed. The pitch control system 30 may generally include a motor 102 having an armature 104 and a winding 106 and a grid power source 110 configured to supply electrical power to the motor 102. The pitch control system 30 may also include a plurality of switching components 120, 122, 124 configured to control a first current through the armature 104 independent of a second current through the winding 106. In addition, the pitch control system 30 may include an auxiliary switching component electrically coupled between the grid power source 110 and at least a portion of the switching components 120, 122, 124. The auxiliary switching component may be configured to be opened when a grid voltage of the grid power source 110 exceeds a first voltage threshold.