Rotary Electric Machine Control Device Independent Inverter Schemes

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Solution Overview

Problem

Existing rotating electrical machine control devices with open-end windings and two inverters lack flexibility in controlling the inverters independently to optimize system efficiency based on operating conditions such as torque and rotational speed.

Innovation Solution

A rotating electrical machine control device that allows independent control of two inverters using different control schemes, including pulse width modulation and active short-circuit control, enabling flexible operation based on the machine's operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the same control scheme is used for both inverters, then the control system is simple, but the system efficiency cannot be optimized based on different operating conditions

Engineering Contradiction:
Improvecontrol flexibilityVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control system is segmented into two independent control units, each capable of selecting different control schemes (PWM, active short-circuit control, or other schemes) for the first and second inverters respectively. This allows independent optimization of each inverter's control strategy based on operating conditions without increasing overall system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system dynamically selects appropriate control schemes for each inverter based on real-time operating conditions such as torque and rotational speed requirements. The control device can switch between PWM, active short-circuit control, and other schemes adaptively to optimize system efficiency

Inventive Principle:
Principle #15Dynamics

2Power

If PWM control is used for both inverters, then the alternating-current voltage amplitude is maximized, but the system lacks flexibility for different operating conditions

Engineering Contradiction:
Improveoutput voltage amplitudeVSAvoidcontrol scheme flexibility
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The system changes control parameters by selecting different control schemes (PWM, active short-circuit control, or other schemes) for the two inverters based on operating conditions. When high voltage amplitude is needed, both inverters use PWM; when efficiency optimization is needed, different schemes can be applied to each inverter independently

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If different control schemes are used for the two inverters, then the system efficiency is optimized, but the control system becomes more complex

Engineering Contradiction:
Improvesystem efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The control device is divided into independent control units for each inverter, allowing different control schemes to be applied to the first and second inverters separately. This segmentation enables efficiency optimization through scheme differentiation while keeping each control unit relatively simple and modular

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device is designed with multi-functionality to support multiple control schemes (PWM, active short-circuit control, and other schemes) that can be applied to either or both inverters depending on operating conditions, achieving efficiency optimization without requiring completely separate control systems

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

Data Source

PatentEP3706309B1Rotary electric machine control device
Publication Date: 2022.03.09 AISIN AW CO LTD
  • EP3706309B1 patent drawingFigure 1
  • EP3706309B1 patent drawingFigure 2~3
  • EP3706309B1 patent drawingFigure 4~5

AI summary

Two inverters provided at both ends of each open-end winding, respectively, are appropriately controlled. A rotating electrical machine control device (1) that has at least two control schemes among pulse width modulation control, active short-circuit control, and rectangular-wave control, as control schemes for a first inverter (11) and a second inverter (12), and that can control the first inverter (11) and the second inverter (12) by control schemes which are independent of each other considers one of the plurality of control schemes as a first control scheme and one of the plurality of control schemes different than the first control scheme as a second control scheme, and has a control mode in which the first inverter (11) is controlled by the first control scheme and the second inverter (12) is controlled by the second control scheme.