Resolver Offset Angle Update After Motor Speed Sign Changes

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Solution Overview

Problem

Changing the speed sign definition of a three-phase electric motor requires recalibrating the resolver offset, which is a cumbersome and time-consuming process, especially since existing methods involve manual or automatic calibration steps.

Innovation Solution

A method to determine a new resolver offset angle based on the present offset angle using pre-defined rules based on the conditions of adjusting the current phase and resolver sequences, eliminating the need for additional calibration steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual or automatic resolver calibration is performed to determine a new resolver offset angle after changing speed sign definition, then measurement precision of the resolver offset is improved, but loss of time and device complexity increase

Engineering Contradiction:
Improveresolver offset angle accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing multiple possible resolver offset angles corresponding to different speed sign definitions and phase sequence configurations. When a change in speed sign definition is required, the system simply retrieves the pre-calculated offset angle from memory based on the new configuration, eliminating the need for time-consuming recalibration procedures while maintaining measurement precision.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual or automatic resolver calibration is performed to determine a new resolver offset angle after changing speed sign definition, then measurement precision of the resolver offset is improved, but device complexity increases

Engineering Contradiction:
Improveresolver offset angle accuracyVSAvoidcalibration process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing multiple possible resolver offset angles corresponding to different speed sign definitions and phase sequence configurations. When a change in speed sign definition is required, the system simply retrieves the pre-calculated offset angle from memory based on the new configuration, eliminating the need for time-consuming recalibration procedures while maintaining measurement precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical/calibration-based system with an informational/computational system. Instead of performing physical calibration procedures involving hardware adjustments and measurements, the system uses software-based lookup tables and computational logic to determine the resolver offset angle, thereby reducing device complexity while maintaining accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If physical connections of the motor are changed to change current phase sequence and resolver sequence, then speed sign definition is correctly changed, but ease of manufacture and ease of operation worsen

Engineering Contradiction:
Improvespeed sign definition correctnessVSAvoidmotor connection complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces physical mechanical changes (swapping cable connections, reconfiguring hardware) with software-based control. The control system detects the desired speed sign definition and automatically adjusts control parameters including current phase sequence and resolver sequence through software, eliminating the need for manual physical reconnection while ensuring correctness of the speed sign definition.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies parameter changes by modifying control software parameters (current phase sequence assignment, resolver sequence interpretation, offset angle selection) rather than changing physical connections. This allows flexible and easy reconfiguration of speed sign definition by simply changing software parameters, greatly improving ease of manufacture and operation while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If physical connections of the motor are changed to change current phase sequence and resolver sequence, then speed sign definition is correctly changed, but loss of time increases

Engineering Contradiction:
Improvespeed sign definition correctnessVSAvoidreconfiguration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces physical mechanical changes (swapping cable connections, reconfiguring hardware) with software-based control. The control system detects the desired speed sign definition and automatically adjusts control parameters including current phase sequence and resolver sequence through software, eliminating the need for manual physical reconnection while ensuring correctness of the speed sign definition.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies parameter changes by modifying control software parameters (current phase sequence assignment, resolver sequence interpretation, offset angle selection) rather than changing physical connections. This allows flexible and easy reconfiguration of speed sign definition by simply changing software parameters, greatly improving ease of manufacture and operation while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4529016A1A method for determining a resolver offset angle of an electric motor
Publication Date: 2025.03.26 POLESTAR PERFORMANCE
  • EP4529016A1 patent drawingFigure 1
  • EP4529016A1 patent drawingFigure 2
  • EP4529016A1 patent drawingFigure 3

AI summary

The present invention relates to a method (100) for determining a new resolver offset angle (0') of a three-phase electric motor after change of a speed sign definition of said electric motor, as well as a device (200) thereof. The speed sign definition is changed by adjusting a current phase sequence and a resolver sequence of the electric motor. The method (100) comprises: obtaining (S102) a present resolver offset angle (θ), wherein the present resolver offset angle (θ) is a resolver offset angle of the electric motor prior to changing the speed sign definition; obtaining (S104) a first condition of the adjustment of the current phase sequence and a second condition of the adjustment of the resolver sequence used to achieve the change of speed sign definition; and determining (S106) the new resolver offset angle (0') based on the present resolver offset angle (θ) and a pre-defined rule, wherein the pre-defined rule is based on the first and second conditions.