Air Conditioner Connection Switching Unit Abnormality Detection
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Solution Overview
Problem
Existing methods for air conditioners cannot detect abnormalities in the connection switching unit, such as short circuits or open connections, which can lead to system malfunctions and secondary failures.
Innovation Solution
A system that includes a controller to detect abnormalities in the connection switching unit by comparing current values when the unit is in different connection states, using a current detection circuit to identify any deviations that indicate a fault, and notifying the user or taking corrective measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a connection switching unit is used to switch between Y-connection and A-connection states, then motor efficiency is improved across different load conditions, but the risk of abnormal connection and system malfunction increases
Solution Approach 1:
The system performs preliminary abnormality detection by applying a detection voltage to the connection switching unit before normal operation and comparing the detected current against reference values. This advance detection identifies potential connection abnormalities before they cause system failures, allowing preventive maintenance while maintaining the efficiency benefits of connection switching.
Solution Approach 2:
The system implements continuous feedback monitoring by detecting current values from the connection switching unit during operation and comparing them against predetermined reference values. When deviations are detected, the system provides feedback signals to alert operators and can trigger protective actions, ensuring system reliability while maintaining efficient motor operation.
2Measurement precision
If conventional abnormality diagnosis methods are used to detect winding short circuits, then winding abnormalities can be detected, but connection switching unit abnormalities cannot be detected
Solution Approach 1:
The system employs a universal detection method that uses current measurement to diagnose both winding abnormalities and connection switching unit abnormalities. By measuring the current drawn by the connection switching unit and comparing it against reference values that account for different connection states (Y-connection, A-connection, and abnormal states), the system achieves multi-functional diagnostic capability without requiring separate detection systems.
Data Source
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AI summary
An air conditioner includes a compressor (114a) to compress a refrigerant used in a refrigeration cycle, a converter (123) to generate a DC voltage, an inverter (126) to generate three-phase AC voltages from the DC voltage, a motor (111) to produce a driving force for driving the compressor (114a) with a plurality of coils (112U, 112V, 112W), the three-phase AC voltages being applied to the coils, a connection switching unit (128) to switch connection states of the coils (112U, 112V, 112W) between a first connection state and a second connection state, and a controller (135) to detect an abnormality of the connection switching unit (128).