Three-Phase Angle Detection Using Modified CORDIC Algorithm

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for calculating the phase shift or amplitude of an electromagnetic three-phase system are complex and require additional calculation steps to determine the quadrant of the magnetic field vector, which complicates the process.

Innovation Solution

A simplified method using three sensors arranged at the same angle on a circular line to detect vector values shifted by 0°, 120°, and 240°, with an iterative Cordic method to calculate the phase shift or amplitude, and optionally using six sensors at 60° intervals to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Clarke transformation is used to convert three-phase data to rectangular coordinate system, then the rotation angle can be calculated, but an additional calculation step is required to determine the quadrant of the magnetic field vector

Engineering Contradiction:
Improveangle calculation accuracyVSAvoidcalculation step complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the problematic quadrant determination step from the Clarke transformation process. By using six Hall sensors arranged at 60° intervals and applying a modified CORDIC algorithm, the method directly calculates the angle without needing to separately determine quadrants, thus removing the source of complexity while maintaining calculation accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the sensor arrangement parameters from the traditional three-sensor 120° configuration to a six-sensor 60° configuration. This parameter change enables the system to obtain magnetic field information from multiple directions simultaneously, allowing direct angle calculation through iterative CORDIC method without quadrant determination steps.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If six sensors are used arranged at 60° intervals on a circular line, then angular resolution and accuracy are improved, but the number of sensors and device complexity increases

Engineering Contradiction:
Improveangular resolutionVSAvoidnumber of sensors
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the magnetic field detection task into six discrete sensing points arranged at 60° intervals around the circular path. Each sensor captures magnetic field information from a specific angular position, and the combined data from all six sensors provides comprehensive angular information with high resolution, enabling precise angle calculation through the iterative process.

Inventive Principle:
Principle #1Segmentation

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

This approach simplifies the calculation of phase shift or amplitude, reducing computational complexity and enabling efficient angle detection in systems like brushless electric motors with improved angular resolution and robustness against incorrect quadrant decisions.

Implementation Method 1

The angle sensor has eight horizontal Hall sensor structures on a semiconductor substrate

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP3270113B1Method for calculating the phase shift or amplitude of a three-phase system
Publication Date: 2021.09.01 TDK MICRONAS GMBH
  • EP3270113B1 patent drawingFigure 1
  • EP3270113B1 patent drawingFigure 2~3
  • EP3270113B1 patent drawingFigure 4

AI summary

A method for calculating the phase shift of an electromagnetic three-phase system is disclosed. This method comprises the following steps: acquiring vector values ​​corresponding to an electromagnetic quantity by three sensors that essentially provide a signal shifted by 0°, 120°, and 240°; calculating modified vector values ​​by logically reversing one of the acquired vector values ​​to a phase angle of 0°; and iteratively calculating the phase shift of the three-phase system using the modified vector values.