Three-phase power supply automatic commutation protection circuit

Abstract

The utility model discloses an automatic commutation protection circuit for a three-phase power supply. The automatic commutation protection circuit comprises an AC contactor KM1; a three-phase control relay K1; the first end, the third end and the fifth end of a normally-open main contact of the alternating current contactor KM1 are connected with the B phase, the A phase and the C phase of the power input end respectively. The second end, the fourth end and the sixth end of the normally-open main contact are connected with the A phase, the B phase and the C phase of the power output end respectively. The seventh end, the ninth end and the eleventh end of the normally-closed main contact are connected with the A phase, the B phase and the C phase of the power input end respectively. The eighth end, the tenth end and the twelfth end of the normally-closed main contact are connected with the A phase, the B phase and the C phase of the power output end respectively. The L1 end, the L2 end and the L3 end of the three-phase control relay K1 are respectively connected with the A phase, the B phase and the C phase of the power supply; the 21 pin is electrified; a pin 22 is connected with one end of a coil of the alternating current contactor KM1; the other end of the coil is grounded. The phase sequence state of the power supply is automatically identified through the three-phase control relay, and the electrified state of the coil of the alternating current contactor is changed according to the phase sequence state, so that the phase sequence of the output end of the three-phase power supply is quickly switched.

Description

Technical Field

[0001] The utility model relates to the technical field of three-phase power protection, in particular to a three-phase power supply automatic phase-changing protection circuit. Background Art

[0002] The mobile shelter is a compartment equipment of a transport vehicle used for geological exploration, water conservancy projects, construction projects, military field operations, etc., which need to work and fight in the field. With the increasing requirements for use, many devices require three-phase power supply, and many devices have specific requirements for the phase sequence of the three-phase power supply. At this time, a protection circuit that can quickly switch the phase sequence when a phase sequence problem occurs in the three-phase power supply is needed to ensure the normal operation of the system. Utility Model Content

[0003] In view of the deficiencies in the prior art, the utility model provides a three-phase power supply automatic phase-changing protection circuit to solve the technical problem in the prior art that when a phase sequence problem occurs in the three-phase power, the phase sequence cannot be switched in time to ensure the normal operation of the load.

[0004] The utility model provides a three-phase power supply automatic phase-changing protection circuit, comprising: an AC contactor KM1; a three-phase control relay K1; a normally open main contact terminal 1, a normally open main contact terminal 3, and a normally open main contact terminal 5 of the AC contactor KM1 are respectively connected to the B phase, the A phase, and the C phase of the three-phase power supply input terminal; a normally open main contact terminal 2, a normally open main contact terminal 4, and a normally open main contact terminal 6 of the AC contactor KM1 are respectively connected to the A phase, the B phase, and the C phase of the three-phase power supply output terminal; a normally closed main contact terminal 7, a normally closed main contact terminal 9, and a normally closed main contact terminal 11 of the AC contactor KM1 are respectively connected to the A phase, the B phase, and the C phase of the three-phase power supply input terminal; The normally closed main contact terminals 8, 10 and 12 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply output terminal; the L1 terminal, L2 terminal and L3 terminal of the three-phase control relay K1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply; the 21st pin of the three-phase control relay K1 is connected to the A phase of the three-phase power supply; the 22nd pin of the three-phase control relay K1 of the three-phase power supply is connected to one end of the coil of the AC contactor KM1; the 24th pin of the three-phase control relay K1 is suspended; the other end of the coil of the AC contactor KM1 is grounded.

[0005] Furthermore, the model of the AC contactor KM1 is: JQ-37F / 220-1.

[0006] Furthermore, the model of the three-phase control relay K1 is: 3UG4618-1CR20.

[0007] Beneficial effects of the utility model:

[0008] The utility model automatically identifies the phase sequence state of the three-phase power supply through a three-phase control relay, changes the energizing state of the coil of the AC contactor according to the phase sequence state, thereby realizing rapid switching of the phase sequence of the output end of the three-phase power supply.

[0009] The utility model uses fewer devices to realize automatic switching of phase sequences, thereby effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0011] Figure 1 It is a circuit diagram of a specific embodiment of the utility model. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0013] The present invention is further described below in conjunction with specific embodiments. Those skilled in the art should understand that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention, and that various equivalent modifications to the present invention fall within the scope defined by the appended claims of this application.

[0014] like Figure 1 As shown, the utility model provides a three-phase power supply automatic phase-changing protection circuit, including: an AC contactor KM1, the model of the AC contactor KM1 is preferably: JQ-37F / 220-1; a three-phase control relay K1, the model of the three-phase control relay K1 is preferably: 3UG4618-1CR20.

[0015] The normally open main contact terminals 1, 3 and 5 of the AC contactor KM1 are connected to the B phase, A phase and C phase of the three-phase power input terminal respectively;

[0016] The normally open main contact terminals 2, 4 and 6 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply output terminal; the normally closed main contact terminals 7, 9 and 11 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply input terminal; the normally closed main contact terminals 8, 10 and 12 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply output terminal;

[0017] The L1, L2 and L3 terminals of the three-phase control relay K1 are respectively connected to the A phase, B phase and C phase of the three-phase power supply; the 21st pin of the three-phase control relay K1 is connected to the A phase of the three-phase power supply; the 22nd pin of the three-phase control relay K1 of the three-phase power supply is connected to one end of the coil of the AC contactor KM1; the 24th pin of the three-phase control relay K1 is suspended; the other end of the coil of the AC contactor KM1 is grounded.

[0018] When in use, when the phase sequence of the three-phase power supply is not disordered, the 21st and 24th pins of the three-phase control relay K1 are in the conducting state. Since the 24th pin of the three-phase control relay K1 is suspended, the coil of the AC contactor KM1 is not energized, and the normally closed main contact and normally open main contact states of the three-phase control relay K1 do not change. The phase sequence of the input end of the three-phase power supply is the same as the phase sequence of the output end, and the phase sequence of the output end is A phase, B phase, and C phase. When the phase sequence of the three-phase power supply is disordered, the three-phase control relay K1 is in the conducting state. Pin 21 and pin 22 of relay K1 are in the on state. Since pin 21 of the three-phase control relay K1 is energized and connected to pin 22 of the three-phase control relay K1, the coil of the AC contactor KM1 is energized, and the normally closed main contact and normally open main contact states of the three-phase control relay K1 are changed. The normally closed becomes disconnected and the normally open becomes attracted. The phase sequence of the input end and the phase sequence of the output end of the three-phase power supply change. The phase sequence of the output end will become phase B, phase A, and phase C, realizing the switching of the phase sequence.

[0019] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A three-phase power supply automatic phase change protection circuit, characterized in that: include: AC contactor KM1; Three-phase control relay K1; The normally open main contact terminals 1, 3 and 5 of the AC contactor KM1 are respectively connected to the B phase, A phase and C phase of the three-phase power input terminal; the normally open main contact terminals 2, 4 and 6 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power output terminal; The normally closed main contact terminals 7, 9 and 11 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power input terminal; the normally closed main contact terminals 8, 10 and 12 of the AC contactor KM1 are respectively connected to the A phase, B phase and C phase of the three-phase power output terminal; The L1, L2 and L3 terminals of the three-phase control relay K1 are connected to the A phase, B phase and C phase of the three-phase power supply respectively; The 21st pin of the three-phase control relay K1 is connected to the A phase of the three-phase power supply; the 22nd pin of the three-phase control relay K1 of the three-phase power supply is connected to one end of the coil of the AC contactor KM1; the 24th pin of the three-phase control relay K1 is suspended; The other end of the coil of AC contactor KM1 is grounded.

2. The three-phase power supply automatic phase-changing protection circuit according to claim 1, characterized in that: The model of the AC contactor KM1 is: JQ-37F / 220-1.

3. The three-phase power supply automatic phase-changing protection circuit according to claim 1, characterized in that: The model of the three-phase control relay K1 is: 3UG4618-1CR20.

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