Motor Bus Voltage Switching for Dual-Mode Actuator Control

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Solution Overview

Problem

In aircraft applications, using separate actuator motors for high lift and variable camber modes increases space, cost, and torque ripple issues due to varying motor operation requirements, as operating a single motor at high input DC voltage is not satisfactory for achieving lower speeds and torques needed for variable camber mode.

Innovation Solution

A motor system with a bus switching scheme that switches the DC input voltage between high and low voltage modes, using a DC bus capacitor and inverter circuit to selectively output energization signals, allowing a single actuator motor to operate effectively in both modes by reducing the DC input voltage from 270VDC to 28VDC for variable camber mode, with a DC link discharge circuit ensuring the capacitor is discharged to a desired level before switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate actuator motors are used for high lift and variable camber modes, then motor performance requirements are met, but space, weight, and cost increase

Engineering Contradiction:
Improvemotor performanceVSAvoidsystem weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent implements a single actuator motor that can operate in both high lift mode and variable camber mode by dynamically switching the DC input voltage level. The motor is designed to handle the full range of torque and speed requirements across both modes, eliminating the need for separate motors for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes the operating parameters of the motor by switching the DC input voltage between high voltage (for high lift mode requiring high torque) and low voltage (for variable camber mode requiring lower torque and speed). This parameter switching allows one motor to adapt to different operational requirements without physical modification.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single motor operates at high input DC voltage for both modes, then space and cost are reduced, but torque ripple and operational satisfaction deteriorate

Engineering Contradiction:
Improvesystem complexityVSAvoidoperational satisfaction
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The system dynamically adjusts the DC input voltage level based on the operational mode requirements. A bus switching circuit monitors the mode and switches between high voltage and low voltage inputs, making the system adaptive rather than static. This dynamic adjustment ensures optimal performance for each mode while using a single motor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a bus switching circuit as an intermediary component that mediates between the power source and the motor. This circuit selectively connects the motor to either high voltage or low voltage DC input based on the required mode, enabling the motor to operate satisfactorily in both modes without direct permanent connection to high voltage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If DC voltage is switched between high and low levels, then motor adaptability improves, but system complexity and switching control requirements increase

Engineering Contradiction:
Improvemode adaptabilityVSAvoidswitching circuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The bus switching circuit incorporates feedback mechanisms to monitor the operational mode and automatically switch the DC voltage level accordingly. The circuit receives input about the required mode and autonomously selects the appropriate voltage level, reducing the need for complex external control systems and minimizing switching complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4354718A1Motor bus switching
Publication Date: 2024.04.17 EATON INTELLIGENT POWER LTD
  • EP4354718A1 patent drawingFigure 1
  • EP4354718A1 patent drawingFigure 2
  • EP4354718A1 patent drawingFigure 3

AI summary

A motor system includes a motor, first and second power rails connected to a DC voltage input terminal, and a DC bus capacitor connected between the first and second power rails. An inverter circuit has a first inverter leg, a second inverter leg and a third inverter leg, each of which includes first and second power switches connected in series between the first and second power rails. The inverter circuit is configured to selectively output energization signals to phase windings of the motor. A DC link discharge circuit is configured to monitor a voltage level of the DC bus capacitor, and a bus switching circuit is configured to selectively output one of a first DC voltage level or a second DC voltage level to the DC voltage input terminal in response to an output of the DC link discharge circuit.