Resolver-to-Digital Conversion Using Speed Offset for Faster Angle Settling
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Solution Overview
Problem
Existing resolver-to-digital converters in traction inverters for electric vehicle motors face challenges in quickly and accurately sensing motor rotation angles and speeds, leading to inefficiencies and longer settling times.
Innovation Solution
A resolver-to-digital converter configuration that includes a feedback filter chain loop and a feedforward filter chain path, where the state observer in the feedback loop offsets the estimated rotation speed from the feedforward path to reduce settling time and improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a traditional feedback filter chain loop is used for resolver-to-digital conversion, then the system structure is simple, but the settling time of the estimated rotation angle is long
Solution Approach 1:
The converter is divided into two independent paths: a feedback filter chain loop for accurate rotation angle estimation and a feedforward filter chain path for fast rotation speed estimation. This segmentation allows each path to be optimized for its specific function, with the feedforward path providing rapid response to reduce settling time while the feedback path ensures accuracy.
Solution Approach 2:
The feedforward filter chain path acts as an intermediary that provides a fast initial estimate of rotation speed to the feedback loop. This intermediary path accelerates the overall system response by providing preliminary information that helps the feedback loop converge faster to the accurate rotation angle.
2Loss of time
If the feedback loop processes rotation speed estimation independently, then the system is stable, but the settling time is prolonged
Solution Approach 1:
The feedback filter chain loop continuously monitors and adjusts the rotation angle estimation based on the actual resolver signals. This feedback mechanism ensures that any deviations or errors in the feedforward path are corrected, maintaining estimation accuracy while benefiting from the reduced settling time provided by the feedforward path.
Data Source
AI summary
A resolver-to-digital converter, comprising: a feedback (FB) filter chain loop having a state observer configured to estimate a rotation speed and a rotation angle of an object, based on a pair of input sine and cosine signals that are amplitude-modulated (AM) to correspond with the rotation angle of the object; and a feedforward (FF) filter chain path configured to estimate the rotation speed of the object based on the pair of input sine and cosine signals, wherein the state observer of the FB filter chain loop is further configured to offset the estimated rotation speed of the FB filter chain loop with the estimated rotation speed of the FF filter chain path to decrease a settling time of the estimated rotation angle.