Motor Drive Carrier Frequency Adjustment for Y-Delta Efficiency

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Solution Overview

Problem

Conventional motor driving technologies face inefficiencies due to the inability to adjust the carrier frequency optimally for both Y connection and delta connection conditions, affecting motor efficiency.

Innovation Solution

A driving device that dynamically adjusts the carrier frequency based on the coil connection condition, using a control system to set distinct carrier frequencies for Y connection and delta connection to optimize motor efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single carrier frequency is used for PWM control, then the control system is simple, but it is impossible to optimize efficiency for both Y connection and delta connection conditions

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

Solution Approach 1:

The patent applies dynamics by making the carrier frequency adjustable rather than fixed. The control system dynamically changes the carrier frequency based on the detected coil connection condition (Y or delta connection), allowing optimization of motor efficiency for each connection mode while maintaining reasonable system complexity through automated adaptation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the carrier frequency parameter according to the coil connection condition. By detecting whether the motor coils are connected in Y or delta configuration, the system adjusts the carrier frequency to optimal values for each connection type, thereby resolving the contradiction between using a single frequency and optimizing for both connection modes.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the carrier frequency is adjusted to optimize efficiency for one connection condition, then efficiency for that condition improves, but efficiency for the other connection condition deteriorates

Engineering Contradiction:
Improvemotor efficiencyVSAvoidadaptability to connection conditions
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts the carrier frequency based on the detected connection condition. When Y connection is detected, one optimal frequency is applied; when delta connection is detected, a different optimal frequency is applied. This dynamic adaptation resolves the contradiction by making the system versatile across different connection conditions while maintaining high efficiency in each mode.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback by detecting the actual coil connection condition and using this information to adjust the carrier frequency accordingly. The control system continuously monitors the connection state and modifies the PWM carrier frequency to match the optimal frequency for the detected configuration, ensuring high efficiency regardless of whether Y or delta connection is active.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3661047B1Drive device, compressor, air conditioner, and method for driving embedded permanent magnet-type electric motor
Publication Date: 2022.11.23 MITSUBISHI ELECTRIC CORP
  • EP3661047B1 patent drawingFigure 1
  • EP3661047B1 patent drawingFigure 2
  • EP3661047B1 patent drawingFigure 3~4

AI summary

A driving device (100) includes a connection switching unit (60) that switches connection condition of a coil (3) between Y connection and delta connection, an inverter (103), and a control device (50) that controls a carrier frequency of the inverter (103). The carrier frequency is set at a first carrier frequency when the connection condition of the coil (3) is the Y connection. The carrier frequency is set at a second carrier frequency when the connection condition of the coil (3) is the delta connection.