Resolver Excitation Signal Amplitude Control for Motor Generator
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Solution Overview
Problem
Conventional rotation angle detection devices using resolvers face inefficiencies due to high power consumption and heat generation when increasing the amplitude or frequency of the excitation signal to improve detection accuracy, and require the same high accuracy during both driving and power generating operations, which is not necessary for power generating operations.
Innovation Solution
A rotation angle detection device with a resolver, excitation circuit, amplification circuit, and switching circuits that adjust the amplitude or frequency of the excitation signal and amplification rate based on the operation mode of the motor generator, optimizing detection accuracy and power consumption accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the amplitude or frequency of the excitation signal is raised to improve the S/N ratio and detection accuracy, then the measurement precision is improved, but the power consumption of the excitation circuit rises
Solution Approach 1:
The excitation signal amplitude is dynamically adjusted based on the operation mode of the motor generator. During driving operations, a high amplitude excitation signal is applied to achieve high detection accuracy. During power generating operations, a low amplitude excitation signal is applied to reduce power consumption. This dynamic adjustment resolves the contradiction between measurement precision and power consumption.
Solution Approach 2:
The amplitude parameter of the excitation signal is changed according to the operation mode. The excitation circuit switches between high amplitude (during driving operations) and low amplitude (during power generating operations), thereby changing the power consumption level while maintaining sufficient detection accuracy for each operation mode.
2Measurement precision
If the amplitude or frequency of the excitation signal is raised to improve detection accuracy, then the measurement precision is improved, but the amount of generated heat rises due to increased loss
Solution Approach 1:
The excitation signal amplitude is dynamically adjusted based on the operation mode. During driving operations, a high amplitude excitation signal is applied to achieve high detection accuracy. During power generating operations, a low amplitude excitation signal is applied to minimize heat generation. This dynamic adjustment resolves the contradiction between measurement precision and heat generation.
Solution Approach 2:
The amplitude parameter of the excitation signal is changed according to the operation mode. The excitation circuit switches between high amplitude (during driving operations) and low amplitude (during power generating operations), thereby changing the heat generation level while maintaining sufficient detection accuracy for each operation mode.
3Measurement precision
If high detection accuracy is maintained during both driving and power generating operations, then the measurement precision is improved, but the power consumption increases unnecessarily during power generating operations
Solution Approach 1:
The excitation signal amplitude is dynamically adjusted based on the operation mode. During driving operations, a high amplitude excitation signal is applied to achieve high detection accuracy. During power generating operations, a low amplitude excitation signal is applied because lower detection accuracy is sufficient for this mode. This dynamic adjustment resolves the contradiction between measurement precision and power consumption during different operation modes.
Solution Approach 2:
The amplitude parameter of the excitation signal is changed according to the operation mode. The excitation circuit switches between high amplitude (during driving operations) and low amplitude (during power generating operations), thereby optimizing the balance between measurement precision and power consumption for each specific operation mode.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves high detection accuracy during driving operations while reducing power consumption and heat generation during power generating operations, enabling downsizing and maintaining sufficient accuracy for rotation speed information.
Implementation Method 1
a resolver which has an excitation coil and an induction coil, and in which a magnetic field formed by an excitation signal applied to the excitation coil is frequency-modulated by rotation of a motor generator and induced in the induction coil
Data Source
AI summary
In a rotation angle detection device for detecting a rotation angle and a rotation speed of a motor generator by using a resolver, a resolver detection accuracy is improved by raising the amplitude or frequency of an excitation signal when the motor generator is performing a driving operation. Furthermore, by reducing the amplitude or frequency of the excitation signal when the motor generator is not performing a driving operation, it is possible to suppress the amount of heat generated by the excitation circuit and the resolver, while maintaining a resolver detection accuracy that enables information about the rotation speed of the motor generator to be obtained.