Wind Turbine Generator Fault Protection via Operational Mode Sensing
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Solution Overview
Problem
Existing fault protection systems for wind turbines, particularly those with permanent magnet generators, struggle to reliably detect faults due to subtle deviations in current levels, which can lead to inadequate protection in situations where circuit breakers do not respond effectively, as they rely on sharp increases in current for protection.
Innovation Solution
A system comprising a generator connected to a power converter via an electrical connection, a circuit breaker system, and a sensor system that monitors operational parameters such as generator speed, power converter status, and circuit breaker status to determine operational modes, identify faults based on expected and actual parameter sets, and implement protective actions, including precise localization of sensing within the machine-side converter to avoid additional power converters and circuit breakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circuit breakers are used for fault protection based on sharp current increases, then protection is provided for over voltages and currents, but fault detection is inadequate for subtle deviations in current levels in permanent magnet generators
Solution Approach 1:
The patent changes the monitored parameters from current levels to operational modes defined by combinations of generator speed, power converter status, and circuit breaker status. This allows detection of faults through deviations in operational mode transitions rather than relying on sharp current increases, thereby improving both reliability and measurement precision for permanent magnet generators
Solution Approach 2:
The patent introduces an intermediary operational mode classification system that mediates between raw sensor data and fault detection. By defining specific operational modes (e.g., generating mode, motoring mode, braking mode) and monitoring transitions between them, the system can detect faults through abnormal mode transitions rather than direct current measurement, resolving the contradiction between reliability and precision
2Reliability
If blade pitch control and braking system are used to slow generator rotation, then generator is halted and power generation stops, but the process is time-consuming and may take up to a few minutes
Solution Approach 1:
The patent performs preliminary classification of operational modes and monitors for abnormal transitions before faults fully develop. By detecting deviations in operational mode sequences and taking protective action at the earliest sign of abnormality, the system reduces fault response time from minutes to seconds while maintaining effective protection
Solution Approach 2:
The patent implements continuous feedback monitoring of operational mode transitions and compares actual sequences against expected sequences. When deviations are detected, the system immediately triggers protective actions, creating a rapid feedback loop that significantly reduces fault response time while ensuring reliable protection
3Ease of operation
If sensor system monitors current levels for fault detection, then circuit breakers can be triggered to open circuits, but the approach is limited where fault currents are only slightly higher than nominal current levels
Solution Approach 1:
The patent changes from monitoring single current level parameters to monitoring combinations of parameters (generator speed, power converter status, circuit breaker status) that define operational modes. This multi-parameter approach maintains ease of operation through standardized mode classification while dramatically improving fault detection accuracy by identifying abnormal mode transitions even when current levels remain near nominal
Data Source
AI summary
A system for a wind turbine that includes a protection system interfaced to a circuit breaker system and a sensing system. The protection system is configured to determine an operational mode of the wind turbine by monitoring at least two parameters determine a parameter set comprising a plurality of operational parameters based on a determined operational mode, and an associated set of expected values corresponding to the parameter set, determine actual values corresponding to the determined parameter set, identify a fault condition in the event that the determined set of actual values of the operational parameters do not correspond to the determined set of expected values of the operational parameters, and implement a protection action based on the identified fault condition.