Resolver Wiring Error Detection via Signal Amplitude Comparison
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Solution Overview
Problem
Resolvers in electric motors often incorrectly wired, leading to inverted position information due to interchanged connections of the excitation winding, which is not reliably detectable with existing technologies.
Innovation Solution
A device with a Zener diode and diode connected in series limits voltage in one current direction, allowing for comparison of the desired and actual excitation signals by increasing frequency and amplitude, enabling detection of correct or incorrect wiring based on amplitude distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the excitation winding connections are interchanged during installation, then the resolver can be connected, but the detected position information becomes inverted and cannot be reliably detected
Solution Approach 1:
The patent applies preliminary action by performing a self-test of the excitation winding connections before normal operation begins. The control device generates a test excitation signal and compares the actual signal with the desired signal to detect wiring errors in advance, preventing incorrect position information from being generated during operation.
Solution Approach 2:
The resolver device performs self-diagnosis through the self-test function, where the control device automatically generates test signals, measures the actual excitation signals, and detects wiring correctness without requiring external intervention or complex additional detection equipment.
2Reliability
If voltage limitation means are added to the excitation winding, then wiring errors can be detected, but the device complexity increases
Solution Approach 1:
The control device performs multiple functions: it generates the desired excitation signal for normal operation, generates the test excitation signal for wiring detection, and compares the actual signal with the desired signal. This multi-functionality eliminates the need for separate dedicated detection equipment, reducing overall device complexity.
Solution Approach 2:
The patent implements feedback by measuring the actual excitation signal at the excitation winding and comparing it with the desired excitation signal. The comparison result provides feedback about wiring correctness, enabling automatic detection of connection errors through signal analysis rather than physical inspection.
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
Reliably identifies correct or incorrect wiring by comparing signal amplitudes, ensuring accurate connection verification and preventing operational errors.
Implementation Method 1
The excitation winding generates a magnetic field in the rotor or respectively in the shaft per induction, which in turn induces a voltage into the receiver winding
Implementation Method 2
Provision is made according to the invention for means to be assigned to the excitation winding for limiting an electrical voltage at the excitation winding, wherein the means limit the voltage only above a maximum voltage in only one current direction
Implementation Method 3
The means preferably comprise a Zener diode and a diode connected in series with the Zener diode
Data Source
AI summary
The invention relates to an apparatus (7) for operating a resolver (1), which has at least one receiver winding (3, 4) or at least one excitation winding (2), which are/can be associated with a rotatably mounted shaft (5), in particular a rotor shaft of an electric motor, said apparatus also having a device (9) which determines an angular position of the shaft (5) as a function of an induced voltage detected by the excitation winding (2) by means of a desired excitation signal (SES) with a predeterminable frequency and amplitude and by the receiver winding (3, 4). According to the invention, means (10) for limiting an electrical voltage on the excitation winding (2) are associated with the excitation winding (2), wherein the means (10) limit the voltage only above a maximum normal voltage in only one current direction.