Outdoor Unit Inverter Reset for Automatic Compressor Restart

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for controlling outdoor units of air conditioners require manual operator intervention for restarting actuators after defects are detected and necessitate additional hardware, such as watchdog timers, which is inefficient and labor-intensive.

Innovation Solution

A control method that performs periodic communication checks to determine defective signals, resets the power supply to the drive circuit, and only restarts the actuator when communication is normal, eliminating the need for new hardware and reducing operator involvement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual restart is performed by operator after defect detection, then the system can be restarted, but operator workload increases and response time is delayed

Engineering Contradiction:
Improveoperator workloadVSAvoidautomatic restart capability
Core Design Contradiction:
Ease of operationVSExtent of automation

Solution Approach 1:

The outdoor unit automatically detects communication defects with actuators and performs self-restart without operator intervention. The control circuit monitors communication status and autonomously restarts the actuator when a defect is detected and resolved, making the system self-servicing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors communication between the control circuit and actuator, providing feedback on communication status. When communication is restored after a defect, the system receives feedback and automatically initiates restart procedures.

Inventive Principle:
Principle #23Feedback

2Reliability

If watchdog timer hardware is added for periodic actuator checking, then automatic defect detection is achieved, but device complexity and cost increase

Engineering Contradiction:
Improveautomatic defect detectionVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The existing control circuit performs multiple functions including communication with actuators, defect detection, and restart control. The control circuit is utilized for dual purposes: normal actuator control and defect monitoring, eliminating the need for dedicated watchdog timer hardware.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The defect detection and restart control functions are merged into the existing control circuit rather than being implemented by separate hardware. The control circuit combines actuator control, communication monitoring, and automatic restart capabilities in a single integrated system.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If actuator is restarted immediately after defect, then operational continuity is improved, but system stability may be compromised

Engineering Contradiction:
Improveoperational continuityVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control circuit performs preliminary checks to confirm communication defect status before initiating restart. It verifies that communication is actually defective and waits for communication restoration before restarting the actuator, ensuring premature restarts are avoided.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a buffering mechanism by monitoring communication status over time and confirming defect conditions before triggering restart. This cushioning approach prevents hasty restart decisions and ensures the system is ready for successful restart.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP1980797B1Outdoor unit for air conditioner and method of controlling the same
Publication Date: 2017.06.21 DAIKIN INDUSTRIES LTD
  • EP1980797B1 patent drawingFigure 1~2
  • EP1980797B1 patent drawingFigure 3
  • EP1980797B1 patent drawingFigure 4

AI summary

When a defect is generated in an actuator of an outdoor unit, the actuator is automatically restarted. An outdoor unit (41) includes an outdoor unit control circuit (411), an inverter substrate (412) and a compressor (413). Periodic communication showing the operating condition of the inverter substrate (412) is set from the inverter substrate (412) to the outdoor unit control circuit (411). Thus, when the communication is performed normally, the drive of the compressor (413) is changed to a power saving process according to the necessity of the power consumption and the operating condition of the inverter substrate (412). When the communication is defective, the power-on reset is done to the inverter substrate (412).