Wind Turbine Pitch Motor Temperature Estimation
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Solution Overview
Problem
Wind turbines often shut down due to the failure of resistance temperature devices (RTDs) monitoring the temperature of pitch drive motors, leading to unnecessary shutdowns when the sensor fails, as there is no effective method to estimate motor temperature in such cases.
Innovation Solution
A method and system that monitor actual temperatures and additional operating conditions of the pitch drive motor during normal operation, determining a relationship between them to estimate motor temperature when the RTD fails, using statistical analysis or machine learning to generate a transfer function for temperature estimation and alarm generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an RTD sensor is used to monitor motor temperature, then temperature monitoring accuracy is improved, but system reliability deteriorates when the sensor fails causing unnecessary shutdowns
Solution Approach 1:
The patent introduces an intermediary estimation system that uses readily available sensor data (current, voltage, speed) and a pre-established transfer function to estimate motor temperature when the RTD fails. This intermediary method acts as a bridge, providing continuous temperature monitoring capability without relying on the fragile RTD sensor, thus maintaining system reliability while the primary high-precision RTD monitoring is temporarily unavailable.
Solution Approach 2:
The patent creates a functional copy of the temperature monitoring capability by using a transfer function that replicates the temperature information from alternative sensor measurements. Instead of directly measuring temperature with the failed RTD, the system copies the temperature information through mathematical relationships derived from other operational parameters, effectively recreating the temperature monitoring function without the original sensor.
2Object-affected harmful factors
If the pitch system shuts down when RTD fails, then safety is improved, but productivity deteriorates due to unnecessary wind turbine downtime
Solution Approach 1:
The patent implements preliminary action by pre-establishing a transfer function during normal operation that correlates readily available sensor data (current, voltage, speed) with motor temperature. This preparatory work is done while the system is functioning normally, so that when the RTD fails, the estimation mechanism is already in place and can immediately take over, preventing unnecessary shutdowns while maintaining safety monitoring.
Solution Approach 2:
The system performs self-service by using its own existing sensor infrastructure (current, voltage, speed sensors) and control infrastructure (pitch controller, converter) to estimate temperature without requiring external or additional hardware. The pitch control system itself generates the estimation data, making the system self-sufficient for temperature monitoring even when the dedicated RTD sensor fails.
3Reliability
If additional sensors are added to estimate temperature, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by making existing sensors and the pitch controller perform multiple functions. The current, voltage, and speed sensors originally designed for motor control now also serve temperature estimation purposes. The pitch controller, which already manages pitch operations, additionally executes the temperature estimation algorithm. This multi-functionality eliminates the need for dedicated temperature estimation hardware, maintaining reliability while avoiding increased complexity.
Data Source
AI summary
A method for estimating a temperature of a motor of a pitch drive mechanism of a rotor blade of a wind turbine includes monitoring, via at least one sensor, an actual temperature and at least one additional operating condition of the motor during a normal operating period of the wind turbine. The method also includes storing, via a pitch controller, the monitored temperatures and the monitored additional operating conditions of the motor for the normal operating period. Further, the method includes determining a relationship between the monitored temperatures and the monitored additional operating conditions of the motor for the normal operating period. Thus, in the event that the sensor fails to operate, the method includes determining, via the pitch controller, an estimated temperature of the motor based on the relationship.