Dual-power power supply circuit and device

Abstract

The invention provides a dual-power power supply circuit and device, the power supply circuit comprises a first phase sequence relay, a second phase sequence relay, a two-position relay, a closing loop and a front loop, coils of the first and second phase sequence relays are respectively connected with a first three-phase power supply and a second three-phase power supply to detect the phase sequence of the first and second three-phase power supplies; the front loop comprises a first normally open contact of the first phase sequence relay, a first normally open contact of the second phase sequence relay and a first coil of the two-position relay which are connected in series, and the closing loop comprises a first branch circuit and a second branch circuit which are connected in parallel, a two-position relay normally open contact which is connected in series with the first branch circuit and the second branch circuit which are connected in parallel, and a closing coil of the circuit breaker. According to the invention, the phase sequences of the first and second three-phase power supplies are detected, so that the situation that the circuit breaker is still switched on when the phase sequences are inconsistent is avoided, and the power supply safety is ensured.

Description

technical field

[0001] The invention relates to a dual power supply circuit and device. Background technique

[0002] With the development of society, users have higher and higher requirements for the continuity of power supply. In the existing low-voltage power distribution system, there are usually two power supplies. Under normal circumstances, the two power supplies supply power to the loads they are responsible for. When a power supply is accidentally cut off, the other power supply can be used as the Emergency power supply, and emergency power supply for all loads at the same time, so as to ensure that the power supply of the power outage is not affected during the maintenance process of the power supply.

[0003] However, in the existing power supply switching technology, the phase sequence of the two power supplies is not detected, and the phase sequence of the two power supplies is likely to be different due to the influence of the transformer manufacturing, line i...

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