Motor Control Device Feedforward Phase Amplitude Generation

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Solution Overview

Problem

Existing motor control methods using feedback control are not sufficiently responsive, leading to instability when noise occurs in the motor current, affecting rotation control accuracy.

Innovation Solution

A motor control device employing a feedforward control method that calculates phase and amplitude command values using a phase generator and amplitude generator, respectively, with a stabilization filter to reduce current vibrations, and a phase converter to apply three-phase voltages to the motor, thereby improving responsiveness and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If feedback control is used to improve rotation control accuracy, then manufacturing precision is improved, but responsiveness deteriorates and noise is amplified

Engineering Contradiction:
Improverotation control accuracyVSAvoidresponsiveness
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The patent applies feedforward control by calculating the phase command value in advance based on the torque command value, without waiting for feedback from current measurements. This preliminary action enables immediate response to torque commands while maintaining rotation control accuracy, resolving the contradiction between responsiveness and precision.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If feedback control is used to improve rotation control accuracy, then manufacturing precision is improved, but stability deteriorates when noise occurs

Engineering Contradiction:
Improverotation control accuracyVSAvoidrotation control stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

By calculating the phase command value in advance through feedforward control based on torque commands rather than reacting to measured currents, the system avoids amplifying noise signals. This preliminary calculation approach maintains both rotation control accuracy and stability under noisy conditions.

Inventive Principle:
Principle #10Preliminary action

3Speed

If feedforward control is used to improve responsiveness, then speed is improved, but measurement precision deteriorates

Engineering Contradiction:
ImproveresponsivenessVSAvoidcurrent measurement accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent extracts the control signal generation from the feedback loop that depends on current measurements. By calculating the phase command value directly from torque commands through feedforward control, the system eliminates dependence on current measurement precision while maintaining high responsiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3474438B1Motor control device and control method
Publication Date: 2021.08.11 NISSAN MOTOR CO LTD
  • EP3474438B1 patent drawingFigure 1
  • EP3474438B1 patent drawingFigure 2
  • EP3474438B1 patent drawingFigure 3

AI summary

A motor control method of the present invention is a motor control method for controlling, by a voltage phase control, an applied voltage applied to a motor via an inverter. The control method includes: calculating a phase command value to be used for the voltage phase control by a feedforward control based on a torque command value to the motor; calculating an amplitude command value to be used for the voltage phase control, based on a drive voltage for the inverter; calculating a voltage command value to the motor based on the phase command value and the amplitude command value; and a voltage application step of applying the applied voltage from the inverter to the motor based on the voltage command value.