Single-Phase Appliance Power Supply Phase Failure Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for ensuring power supply during phase failures in three-phase electric distribution systems are complex, costly, and inefficient, particularly for single-phase appliances, as they rely on accumulator-based systems that limit performance and have short lifetimes, and are not suitable for frequent single-phase failures.
Innovation Solution
A method and device that detect voltage failures in one or multiple phases and automatically switch the power supply to available phases, using sensors and cascaded switches to ensure continuous power without the need for accumulators, thereby preventing inter-phase short circuits and maintaining reliability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If accumulator-based back-up power supply systems are used to ensure power during phase failures, then power supply continuity is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the accumulator component from the back-up power supply system. Instead of using accumulators with converters, the invention directly switches the single-phase appliance to another available phase from the three-phase distribution system when a phase failure is detected, thereby simplifying the system architecture while maintaining power supply continuity.
Solution Approach 2:
The switching device in the patent serves multiple functions: it monitors phase availability, detects failures, and performs automatic switching between phases. This multi-functional approach replaces the need for separate accumulator-based back-up systems, reducing overall system complexity while ensuring reliable power supply during phase failures.
2Reliability
If accumulator-based back-up power supply systems are used, then power supply during failure is improved, but accumulator lifetime decreases
Solution Approach 1:
The invention removes the accumulator from the power supply chain entirely. By directly switching to an available phase in the three-phase distribution system, the system eliminates the wear and degradation issues associated with accumulator-based systems, thereby ensuring unlimited operational life while maintaining power supply reliability during phase failures.
3Reliability
If On-Line connection with converter is used, then power supply continuity is improved, but overall efficiency decreases
Solution Approach 1:
The patent eliminates the converter component from the power supply path. By directly connecting the appliance to an available phase through a simple switching mechanism, the system avoids the energy losses inherent in converter operations while maintaining continuous power supply during phase failures.
Solution Approach 2:
The three-phase distribution system itself provides the back-up power capability without requiring active conversion or accumulation. The system leverages the existing infrastructure by switching to another phase that is already available and energized, thereby maintaining efficiency while ensuring reliability.
4Reliability
If three-phase back-up source with three converters and three batteries is used, then power supply reliability during all phase failures is improved, but device complexity and cost increase
Solution Approach 1:
The patent employs a single switching device that can handle all phase failure scenarios by switching to any of the remaining available phases. This universal switching mechanism replaces the need for three separate converters and batteries, significantly simplifying the construction while maintaining the ability to provide back-up power for all phase failure conditions.
Solution Approach 2:
The invention merges the functions of multiple converters and batteries into a single switching mechanism. By consolidating the back-up power functionality into one device that leverages the existing three-phase distribution system, the patent reduces construction complexity and cost while ensuring reliable power supply during any phase failure scenario.
Data Source
Figure 1a~1c
Figure 2~3
AI summary
During the detection of the failure of the voltage on the first phase and the power supply of the appliance the power supply is on the basis of the instructions from the control unit (1) connected to the second phase; in case of the failure on the second phase the power supply of the appliance is connected to the available third phase. The device can have in preferable arrangement an accumulator (9) with the converter (10); in such case, after determining the outage on all available phases, the power supply of the appliance is connected to the output of the converter (10). The failure of the power supply in a given phase is detected by a single sensor (3) which is placed on the supply branch on the side of the plug (4) behind the point of switching of the phases. The device can have three switches (21, 22, 23) with two input poles ordered one after another in a cascade, whereby the output from the first switch (21) is connected to the first input pole (22a) of the second switch (22); the output from the second switch (22) is connected to the the first input pole (23a) of the third switch (23); and the output from the third switch (23) is connected to the plug (4).