Motor Drive Control Device Dynamic Converter Operation

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Solution Overview

Problem

Existing motor drive control devices are inefficient in reducing the size of the power supply converter and optimizing the energy storage device, leading to increased size and cost, despite the use of energy storage devices to manage varying motor loads and speeds.

Innovation Solution

A motor drive control device that includes a power supply converter connected to an alternating-current power supply, a voltage detector, an inverter connected to a motor, and an energy storage device on a direct-current bus, with an operation voltage determination section and a voltage setting operation control section to start or stop the power supply converter based on set voltage thresholds, optimizing energy transfer and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the power supply converter always operates to handle varying motor loads and speeds, then the adaptability and generality of the motor drive control device is improved, but the thermal rating of the power supply converter must be increased, leading to larger size and higher losses

Engineering Contradiction:
ImproveadaptabilityVSAvoidsize of power supply converter
Core Design Contradiction:
Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The power supply converter operates dynamically - starting and stopping based on whether the motor is in acceleration or deceleration phases. This dynamic operation allows the converter to handle varying loads adaptively while avoiding continuous operation, thereby reducing the required thermal rating and size of the converter.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The power supply converter operates periodically rather than continuously, activating during acceleration periods when power is needed and stopping during deceleration periods when the motor generates power. This periodic action reduces average power consumption and thermal load, allowing for a smaller converter design.

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If the power supply converter always operates to handle varying motor loads and speeds, then the adaptability and generality of the motor drive control device is improved, but operational losses increase

Engineering Contradiction:
ImproveadaptabilityVSAvoidoperational losses
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The power supply converter operates periodically rather than continuously, activating during acceleration periods when power is needed and stopping during deceleration periods when the motor generates power. This periodic action reduces average power consumption and thermal load, allowing for a smaller converter design.

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces the size and weight of the power supply converter while improving efficiency and optimizing the energy storage device capacity, allowing for fine operation control and reduced thermal ratings, thus minimizing cooling requirements and operational losses.

Implementation Method 1

an energy storage device that is connected to a direct-current bus that connects the power supply converter and the inverter

Methodology Applied
Scientific EffectEnergy storage: Electrical Accumulator

Implementation Method 2

a voltage detector that detects a direct-current voltage of the power supply converter

Methodology Applied
Scientific EffectVoltage detection: Ohmmeter

Data Source

PatentEP2214302B1Motor drive control device
Publication Date: 2013.06.26 HITACHI IND EQUIP SYST CO LTD
  • EP2214302B1 patent drawingFigure 1
  • EP2214302B1 patent drawingFigure 2
  • EP2214302B1 patent drawingFigure 3

AI summary

A motor drive control device including a power supply converter that is connected to an alternating-current power supply, a voltage detector that detects a direct-current voltage of the power supply converter, an inverter that is connected to a motor, and an energy storage device that is connected to a direct-current bus that connects the power supply converter and the inverter. The motor drive control device has an operation voltage determination section that determines whether or not the direct-current voltage of the power supply converter is equal to or lower than a power-running operation voltage set by a power-running operation voltage setting section. The motor drive control device has a voltage setting operation control section that causes the power supply converter to start a power-running operation when the direct-current voltage is equal to or lower than the power-running operation voltage, and causes the power supply converter to stop the power-running operation when the direct-current voltage has exceeded the power-running operation voltage.