Inverter Power-Saving Control for Same Load Pattern Devices

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Solution Overview

Problem

Existing methods for reducing power loss in devices with a same load pattern, such as industrial machines, fail to consider the loss characteristics of all constituting elements and require preliminary experiments to determine optimal carrier wave frequencies, making them inefficient and labor-intensive.

Innovation Solution

A power-saving driving device and method that includes an electric power amount calculator and a parameter selection and command device, which calculates and compares the electric power received by the inverter for various parameter values, selecting the parameter that minimizes loss without requiring preliminary data on loss characteristics, and automatically adjusts parameters like carrier wave frequency and voltage change rate to optimize power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If preliminary experiments are conducted to determine optimal carrier wave frequency, then power loss reduction can be achieved, but labor and time are required for optimization

Engineering Contradiction:
Improvepower lossVSAvoidoptimization time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The inverter controller automatically measures actual power loss and determines optimal carrier wave frequency without external intervention. The controller performs self-diagnosis by measuring power input, calculating power loss, and autonomously selecting optimal parameters, eliminating the need for manual preliminary experiments and reducing optimization time.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a feedback mechanism where the controller continuously measures actual power loss, compares it with expected values, and adjusts carrier wave frequency accordingly. This closed-loop control enables automatic optimization based on real-time measurements, replacing time-consuming preliminary experiments with rapid iterative adjustment.

Inventive Principle:
Principle #23Feedback

2Loss of energy

If comprehensive loss characteristics data is collected for all constituting elements, then optimal parameter selection can be made, but measurement and data collection complexity increases

Engineering Contradiction:
Improvepower lossVSAvoidmeasurement complexity
Core Design Contradiction:
Loss of energyVSDifficulty of detecting and measuring

Solution Approach 1:

The patent combines multiple measurement functions into a single integrated controller that measures power input, calculates power loss, and determines optimal parameters simultaneously. By merging these functions, the system avoids the complexity of separate measurement devices and procedures for each constituting element, while still achieving comprehensive loss characterization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The controller acts as an intermediary that indirectly measures total system loss without requiring direct measurement of each individual component's loss characteristics. By measuring power input and using calculations based on motor output and efficiency maps, the controller determines optimal parameters without complex direct measurements of wiring, filters, and other constituting elements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If fixed carrier wave frequency is used, then control simplicity is maintained, but power loss cannot be optimized for varying operating conditions

Engineering Contradiction:
Improvepower lossVSAvoidcontrol complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system transitions from fixed carrier wave frequency to dynamic adjustment based on operating conditions. The controller automatically varies carrier wave frequency according to motor speed, torque, and temperature conditions, enabling power loss optimization across different operating points while maintaining relatively simple control logic through automated decision-making.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements automatic parameter changes in carrier wave frequency and voltage change rate based on measured operating conditions. The controller selects optimal parameters from predefined ranges or adjusts them continuously, enabling power loss reduction without requiring complex control algorithms, as the parameter selection is based on straightforward measurements and lookup tables.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2413497B1Device and method for power-saving driving of device having same load pattern
Publication Date: 2019.06.19 IHI CORP
  • EP2413497B1 patent drawingFigure 1
  • EP2413497B1 patent drawingFigure 2
  • EP2413497B1 patent drawingFigure 3

AI summary

A power-saving driving device is provided for a same load pattern device 23 that is driven by a motor 21 receiving electric power from an inverter 19 and repeatedly operated in a same load pattern. The power-saving driving device includes: an electric power amount calculator 81 that calculates an electric power amount W received by the inverter in the same load pattern; and a parameter selection and command device 83 that makes a parameter of the inverter change to a plurality of values, compares the received electric power amounts corresponding to the values of the parameter, selects the parameter value minimizing the received electric power amount and issues the selected value as a command to the inverter.