N-Phase Overlapping Automatic Transfer Switch
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Solution Overview
Problem
Conventional automatic transfer switches often cause potential differences and malfunctions in electronic equipment due to phase differences during switching between normal and emergency power supplies, leading to unexpected high voltages and floating phenomena.
Innovation Solution
An automatic transfer switch with an N-phase overlapping structure, where the normal and emergency power supplies overlap in a neutral contact (N phase) before switching between the three-contact (R, S, T phases), ensuring no physical time difference and preventing potential differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the neutral contact (N phase) is opened 10-12 ms after the other 3 contacts (R, S, T phases) to extinguish arc, then the arc-extinguishing time is reduced, but the opening time gap between neutral contact and other contacts is less than 10 ms causing potential difference and equipment malfunction
Solution Approach 1:
The patent applies preliminary action by establishing the neutral contact connection before switching the three-phase contacts. The neutral contact is connected to the emergency power supply in advance, and the load neutral terminal is pre-connected to the normal power supply neutral terminal. This preliminary configuration ensures that when the three-phase contacts switch, the neutral reference potential is already established, preventing potential differences and floating phenomena during the transition.
2Speed
If the conventional ATS switching sequence is used to enable quick power transfer, then the switching speed is improved, but phase difference occurs between load side voltage and emergency power side voltage causing high voltage and equipment damage
Solution Approach 1:
The neutral contact is connected to the emergency power supply before the three-phase contacts switch, pre-establishing the neutral reference potential. This preliminary action ensures that when the three-phase contacts close to emergency power, there is no potential difference between the load side and emergency power side, eliminating the risk of high voltage spikes and equipment damage while maintaining fast switching speed.
Solution Approach 2:
The patent ensures equipotentiality by connecting the neutral contact to the emergency power supply before switching the three-phase contacts. This creates the same potential level between the load side neutral terminal and emergency power supply neutral terminal in advance, preventing potential differences and harmful voltage spikes during the power transfer process.
Data Source
AI summary
Proposed is an automatic transfer switch with an N-phase overlapping structure, the switch including: a driving unit including a drive shaft provided to generate power; a three-contact switching unit including a normal power shaft and an emergency power shaft provided to be rotated by the drive shaft, and a normal power terminal and an emergency power terminal for inputting/releasing normal power and emergency power; and an N-phase overlapping unit including a first insertion part having a first insertion hole, an N-phase normal contact terminal provided to input/release an N-phase normal power, a second insertion part having a second insertion hole, an N-phase emergency contact terminal provided to input/release an N-phase emergency power, and a connection bar connected between the first insertion part and the second insertion part so as to be interlocked with each other.