Three-Phase Connection Error Detection via Voltage Rectification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The alternating-current power supply of three-phase four-line type is prone to connection errors due to the large number of lines, leading to incorrect voltage application to loads, which can damage control circuits and disrupt the operation of 400V-system loads.
Innovation Solution
A connection-error detection apparatus that includes a voltage detection circuit with a full-wave or half-wave rectification circuit, a timer circuit, and a switch, which automatically detects connection errors and open phases by monitoring the output voltage and generating reset signals to prevent excessive voltage from reaching 230V-system loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual wiring connection is used to connect phase lines and power supply terminals, then installation flexibility is maintained, but connection errors occur due to human mistake
Solution Approach 1:
The patent applies preliminary action by equipping the power supply terminal with a detection apparatus that automatically identifies and indicates the correct connection positions for phase lines before the actual wiring is performed. The detection apparatus includes voltage detection circuits that measure voltages between terminal pairs and display the correct phase line assignments, allowing the installer to connect wires according to visual guidance rather than relying on memory or color codes alone.
Solution Approach 2:
The patent implements feedback by using the detected voltage information to provide real-time guidance to the installer. The detection apparatus continuously monitors the connection status and provides visual feedback through display elements (such as LEDs or screens) that indicate whether a phase line is correctly connected to its designated terminal. This closed-loop feedback system allows immediate correction of connection errors.
2Reliability
If connection error detection apparatus is added to the power supply terminal, then connection accuracy is improved, but device complexity increases
Solution Approach 1:
The detection apparatus is designed with multi-functionality to reduce overall system complexity. The same voltage detection circuits serve multiple purposes: they detect connection errors, identify open phases, measure voltage magnitudes, and provide diagnostic information. By consolidating these functions into a single integrated apparatus rather than separate devices, the patent minimizes the increase in device complexity while maximizing reliability improvements.
Solution Approach 2:
The power supply terminal performs self-diagnosis and self-identification of correct connections through the integrated detection apparatus. The system automatically measures voltages, processes the data, and generates connection guidance without requiring external testing equipment or complex installation procedures. This self-service capability reduces the complexity burden on the installer and the overall system.
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
The apparatus effectively detects connection errors and open phases, preventing damage to 230V-system loads by ensuring that only appropriate voltages are applied, thereby ensuring safe operation of both 230V and 400V-system loads.
Implementation Method 1
a rectification circuit which is connected to each of the phase lines L1, L2, and L3
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Voltages of respective phase lines (L1, L2, L3) of an alternating-current power supply (1) of three-phase four-line type are rectified by a full-wave rectification circuit (11), and whether an output voltage (11) of the full-wave rectification circuit is above a predetermined value or not is determined. If a determination result thereof continuously indicates being above the predetermined value for a constant time, connection to the alternating-current power supply (1) of three-phase four-line type is determined to be not an error. If the determination results does not continuously indicates being above the predetermined value for the constant time, the connection to the alternating-current power supply (1) of three-phase four-line type is determined to be an error.