Rotary Machine Stator Winding Switching Detection During Operation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for determining the successful completion of stator winding switching in rotary machines are prone to errors due to impedance imbalances and varying operation times, leading to incorrect determination of switching success.

Innovation Solution

A rotary-machine control device that applies pulse voltages between phases of the stator windings and measures current response to accurately determine the presence of open phases during rotation, using a method that requires only tens to hundreds of microseconds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the capacity of the rotary machine is increased to meet growing cooling and heating demands, then the power consumption increases, but the energy efficiency deteriorates due to frequent on-off operations

Engineering Contradiction:
ImprovecapacityVSAvoidpower consumption
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The rotary machine operates in variable capacity modes (first capacity, second capacity, third capacity) rather than fixed on-off operation. The capacity is dynamically adjusted based on running time comparisons, allowing the system to meet varying cooling/heating demands while maintaining continuous operation and improving energy efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operating capacity parameter of the rotary machine based on running time accumulation. When running time exceeds a threshold, the capacity switches between different levels, optimizing energy consumption while maintaining required cooling/heating performance

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the rotary machine operates at high capacity to meet peak demands, then the cooling and heating performance improves, but the wear on components increases and reliability decreases

Engineering Contradiction:
Improvecooling and heating performanceVSAvoidcomponent wear
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The rotary machine dynamically adjusts its capacity operation rather than continuously running at high capacity. By switching between first, second, and third capacities based on running time thresholds, the system maintains required performance while reducing mechanical stress and component wear

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements periodic capacity adjustment based on accumulated running time. The capacity is not fixed but periodically changed between different levels, allowing the machine to meet peak demands when necessary while reducing overall wear through varied operation cycles

Inventive Principle:
Principle #19Periodic action

3Device complexity

If a simple on-off control system is used for the rotary machine, then the device complexity is low, but the energy efficiency and performance optimization are insufficient

Engineering Contradiction:
Improvecontrol system complexityVSAvoidenergy efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The control device monitors the running time of the rotary machine and uses this feedback to determine when to switch between different capacity modes. This feedback mechanism enables automatic optimization of energy efficiency without requiring complex control algorithms or additional sensors

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device automatically adjusts the rotary machine capacity based on accumulated running time data. The system serves itself by making capacity decisions based on its own operational history, eliminating the need for external manual control or complex external control systems

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3917000B1Rotary machine control device, refrigerant compression apparatus, and air-conditioner
Publication Date: 2026.04.15 MITSUBISHI ELECTRIC CORP
  • EP3917000B1 patent drawingFigure 1
  • EP3917000B1 patent drawingFigure 2
  • EP3917000B1 patent drawingFigure 3

AI summary

A rotary-machine control device includes: a connection switching device (7) switching a connection state of stator windings (11 to 13) of a rotary machine (1); a current detection unit (4) detecting a rotary machine current flowing in the rotary machine (1); a voltage application unit (3) applying voltage to the rotary machine (1); a control unit (5) generating a voltage command provided to the voltage application unit (3) and outputting a switching command to switch the connection state to the connection switching device (7); and an open-phase determination unit (6) determining presence or absence of disconnection in the rotary machine (1) or presence or absence of disconnection of a power distribution line to the rotary machine (1). During rotation of the rotary machine (1), the control unit (5) outputs the switching command and the open-phase determination unit (6) determines presence or absence of disconnection.