Inverter Fan Control via DC-Link Voltage and Temperature

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Solution Overview

Problem

Inverter systems face challenges in suppressing temperature increases of Switched-Mode Power Supply (SMPS) and peripherals when the inverter is stopped, as conventional methods either require constant fan operation, consuming power or require additional components with limited effectiveness.

Innovation Solution

A method involving a controller that uses internal temperature and DC-link voltage to determine when to drive or maintain the fan operation, optimizing convection and reducing temperature increases by outputting fan driving or stopping signals based on predetermined settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the fan is constantly driven to suppress temperature increase of SMPS and peripherals, then temperature control is improved, but power consumption increases

Engineering Contradiction:
Improvetemperature of SMPS and peripheralsVSAvoidpower consumption of fan
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The fan operation mode is changed from static (constant driving) to dynamic (adaptive control). The controller adjusts fan operation based on real-time monitoring of DC-link voltage and internal temperature, switching between stop, intermittent, and constant driving modes according to actual thermal conditions and power availability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses its own operational parameters (DC-link voltage and internal temperature) to automatically control its cooling system. The inverter monitors its own state and self-regulates fan operation without external intervention, optimizing cooling efficiency while minimizing power consumption.

Inventive Principle:
Principle #25Self-service

2Use of energy by moving object

If the inverter is stopped, then power consumption is reduced, but temperature increase of SMPS occurs due to load reduction and deterioration in internal convection

Engineering Contradiction:
Improvepower consumption of inverterVSAvoidtemperature of SMPS
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The system performs preliminary cooling action by driving the fan during operation to prevent excessive temperature accumulation. When the inverter is stopped, the fan may continue to operate intermittently or constantly based on temperature and voltage conditions, addressing the thermal issue before it becomes critical.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fan operates in periodic intervals when the inverter is stopped, rather than continuously. The controller activates the fan at specific intervals based on monitored temperature and DC-link voltage levels, providing sufficient cooling while minimizing power consumption during idle periods.

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 approach efficiently suppresses temperature increases of SMPS and peripherals by improving convection within the inverter system, reducing power consumption compared to constant fan operation and avoiding the need for additional components.

Implementation Method 1

Temperature of the SMPS and the peripherals comes to increase due to load reduction of the SMPS and deterioration in internal convection of the inverter, when the inverter and the fan are stopped

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

A heat sink at a lower part of the invert can prevent a three-leg switch at an output part of the inverter from an excessive temperature increase

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Data Source

PatentEP2958412B1Method for controlling temperature of inverter system by controlling a fan
Publication Date: 2020.01.22 LSIS CO LTD
  • EP2958412B1 patent drawingFigure 1~2
  • EP2958412B1 patent drawingFigure 3
  • EP2958412B1 patent drawingFigure 4

AI summary

A method for controlling temperature of an inverter system having an inverter and a cooling fan is provided, the method including: obtaining an internal temperature of the inverter and a DC (Direct Current)-link voltage of the inverter; and outputting a fan driving control signal for driving the fan or maintaining the fan being driven to the fan, when the internal temperature is above a predetermined fan drive setting temperature and the DC-link voltage is above a predetermined fan drive setting voltage.