To effectively achieve power control and braking control functions, the pitch system must establish communication with the main control system. This system is responsible for gathering essential parameters such as impeller speed, generator speed, wind speed and direction, temperature, and others. The pitch angle adjustments are controlled through the CAN communication protocol to optimize wind energy capture and ensure efficient power management.
The wind turbine slip ring facilitates power supply and signal transmission between the nacelle and the hub-type pitch system. This includes the provision of a 400VAC+N+PE power supply, 24VDC lines, safety chain signals, and communication signals. However, the coexistence of power and signal cables in the same space poses challenges. Since the power cables are predominantly unshielded, their alternating current can generate alternating magnetic flux in the vicinity. If the low-frequency electromagnetic energy reaches a certain threshold, it can generate an electric potential between the conductors within the control cable, leading to interference.
Additionally, a discharge gap exists between the brush and the ring channel, which can cause electromagnetic interference due to arc discharge under high voltage and high current conditions.
To mitigate these issues, a sub-cavity design is proposed, wherein the power ring and auxiliary power ring are housed in one cavity, while the Anjin chain and signal ring occupy another. This structural design effectively reduces electromagnetic interference within the slip ring's communication loop. The power ring and auxiliary power ring are constructed using a hollow structure, and the brushes are composed of precious metal fibre bundles made from pure alloys. These materials, including military-grade technologies such as Pt-Ag-Cu-Ni-Sm and other multi-alloys, ensure exceptionally low wear over the lifespan of the components.
Post time: Jan-26-2025
