Generator Controller Misalignment Measurement
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Solution Overview
Problem
Existing controller devices for power converter devices of generators are complex due to the need to handle conditions around zero speed and zero volts, requiring sophisticated control strategies that are not necessary in pure generator applications, and there is a need for a simplified technique to manage misalignment between controller axes and rotor flux.
Innovation Solution
A vector controller device uses a d-axis regulator with proportional, integral, and differential components to measure misalignment, and includes an error unit that utilizes an estimated stator back electromotive force signal to create an error signal proportional to the angle of misalignment, with a phase-locked loop to process this signal and adjust the controller's reference frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a vector controller device uses a d-axis regulator with proportional, integral, and differential components to measure misalignment, then the control precision is improved, but the device complexity increases
Solution Approach 1:
The patent introduces an error unit as an intermediary component that processes the d-axis regulator output and divides it by the estimated stator back electromotive force. This intermediary structure transforms the complex misalignment measurement into a simplified error signal that is proportional to the misalignment angle, thereby improving measurement precision while avoiding direct complex calculations in the main control path
Solution Approach 2:
The patent transforms the misalignment measurement problem by changing the parameter representation. Instead of directly measuring the misalignment angle through complex methods, the system uses the d-axis regulator output divided by the back electromotive force to create an error signal that is proportional to the misalignment angle. This parameter transformation simplifies the measurement process while maintaining precision
2Adaptability or versatility
If the controller handles conditions around zero speed and zero volts, then the adaptability is improved, but the control strategy complexity increases
Solution Approach 1:
The patent extracts the misalignment measurement function from the main control strategy by using the d-axis regulator output as a dedicated indicator. This separation allows the controller to handle zero speed and zero volts conditions through the same streamlined error signal generation process, improving adaptability without increasing overall control strategy complexity
Solution Approach 2:
The error unit serves multiple functions: it processes the d-axis regulator output, divides by the back electromotive force, generates the error signal proportional to misalignment angle, and feeds it to the phase-locked loop. This multi-functional component handles various operating conditions including zero speed and zero volts through a single unified approach, enhancing adaptability while avoiding separate control strategies
3Measurement precision
If an error unit divides the d-axis response by the estimated stator back electromotive force, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The error unit performs a parameter transformation by dividing the d-axis response by the estimated stator back electromotive force. This mathematical operation converts the raw d-axis regulator output into an error signal that is directly proportional to the misalignment angle, significantly improving measurement precision. The division operation is implemented as a standard computational step within the existing controller architecture, adding minimal complexity while achieving precise angle measurement
Data Source
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AI summary
It is described a controller device (200) for controlling a power converter device (202) of an electrical generator (204) during rotation of the electrical generator (204). A signal converter (218) of the controller device (200) is configured for receiving an angle signal (220) and in response hereto transposing a current feedback (222, 224) onto two axes of a rotating d,q-reference frame. Further, a current controller (226) is provided, the current controller (226) having a regulator (228) receiving a d-axis feedback (222) and a d-axis demand (214) and providing in response hereto a d-axis response (230) operative in reducing the difference between the d-axis feedback (222) and the d-axis demand (214). An error unit (232) of the controller device provides an error signal (234) indicative of an angle error of the rotating reference frame on the basis of the d-axis response (230) of the d-axis regulator (228).