CN107863754B - A kind of transformer leakage stream automatic earthing electric installation - Google Patents

Abstract

The invention discloses a transformer leakage current automatic grounding conductive device, which is connected to a transformer connected to a leakage current acquisition circuit and a leakage current acquisition device on a PLC control device, and includes a fixed bracket and a grounding guide rod, and the fixed bracket is fastened on the The bottom position of the transformer shell, and the grounding guide rod is rotatably connected to the fixed bracket through the release motor and the release device; and the release motor is connected to the PLC control device of the transformer through the leakage current normally open switch to obtain its working instructions; release device. A transformer leakage current automatic grounding conductive device of the present invention, on the one hand, realizes the real-time automatic grounding of the leakage current, and on the other hand, sets up a protection circuit for leakage current leakage, which has high reliability and low implementation cost.

Description

A transformer leakage current automatic grounding conductive device

technical field

The invention relates to the field of transformer leakage protection device and system technology, in particular to a transformer leakage current automatic grounding conductive device.

Background technique

The power system currently uses a large number of power system transformers, and the windings in the transformer are also one of the most basic components of the transformer. It is the circuit part of the transformer, usually wound with copper wire or aluminum wire wrapped in insulating paper. The winding connected to the high-voltage grid is a high-voltage winding, and the winding connected to the low-voltage grid is a low-voltage winding. Large power transformers use concentric windings. It sets the high and low voltage windings concentrically on the iron core column. Usually the low voltage winding is close to the core and the high voltage winding is on the outside.

Nowadays, many power system transformers operate in complex environments. In this case, it is inevitable that the winding insulation paper in the transformer is damaged or corroded and becomes brittle, which will cause leakage defects. At present, it has not been used in power system transformer windings. Leakage protection technology.

There are already some protective devices for low-voltage distribution transformers (referred to as transformers). For example, there are various high-voltage circuit breakers, lightning arresters, etc. on the high-voltage side, and various fuses, AC contactors, phase-detection and amplitude-detection relays, etc. on the low-voltage side. Despite such protective measures, due to the variety of transformer capacity levels and complex circuits, it is difficult to ensure that the various protective measures are foolproof, especially the leakage fault of the transformer, which may occur in any part, and the general leakage protection is in the main circuit, and the effectiveness of the leakage protection circuit itself cannot be monitored in real time, resulting in the failure to detect transformer leakage faults in time, leading to accidents, especially for transformer maintenance personnel and personnel around the transformer. It is easy to cause an electric shock accident.

SUMMARY OF THE INVENTION

In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a transformer leakage current automatic grounding conductive device capable of directing and grounding the leakage current in real time.

The technical solution adopted in the present invention is: a transformer leakage current automatic grounding conductive device, which is connected to a transformer with a PLC control device and a leakage current acquisition circuit, wherein the PLC control device is connected to the leakage current acquisition circuit, and the leakage current acquisition circuit is connected to The leakage current acquisition device includes a fixed bracket and a grounding guide rod, the fixed bracket is fastened at the bottom of the transformer housing, and the grounding guide rod is rotatably connected to the fixed bracket through the release motor and the release device; and the release motor Connect to the PLC control device of the transformer through the leakage current normally open switch to obtain its working instructions;

The release device includes a rotating support arm and a plug-in support rod. One end of the rotating support arm is connected to the fixed bracket through a rotating shaft to rotate, and the grounding guide rod is lapped above the plug-in support rod. At the same time, the motor is released to connect the plug-in support rod to pull. And the release motor is connected to the fixed bracket through the sliding bracket to slide and plug in.

Further, the grounding guide rod is made of a flipped connecting rod and a flexible connecting rope, which is a two-stage structure as a whole. The flipped connecting rod is used to be rotatably connected to the fixed bracket, and the flexible connecting rope at the other end is the grounding end. The flexible connecting rope A long strip member made of one or more of steel cables, steel plates, and square steel.

Further, the end of the flexible connecting rope is also connected to a metal grounding ball, and the diameter of the metal grounding ball is at least five times that of the flexible connecting rope.

Further, the leakage current acquisition circuit includes an inductance sensor and a current sensor; the leakage current acquisition device includes at least three conductive members uniformly arranged around the outer casing of the transformer, and each conductive member is respectively connected to the inductance sensor and the current sensor of the leakage current acquisition circuit .

Further, the leakage current acquisition circuit is also connected to the power supply of the transformer through the overcurrent protector. When the leakage current guided by the automatic grounding conductive device exceeds a second and still cannot reach the safe current, the transformer PLC control device activates the overcurrent protector. Turn off the transformer.

Further, a sound alarm device and a flash alarm device are also connected to the leakage current acquisition circuit.

Compared with the prior art, the beneficial effect of the present invention is: a transformer leakage current automatic grounding conductive device of the present invention cooperates with the real-time grounding conduction transformer leakage protection system, on the one hand, it realizes the real-time conduction grounding of the leakage current On the other hand, a protection circuit for leakage current leakage is set up, that is, the automatic grounding conductive device is connected to the leakage current acquisition circuit of the transformer and the PLC control device through the leakage current normally open switch to obtain the current diversion status signal, and at the same time, the leakage current Connect the power supply of the transformer through the overcurrent protector. When the leakage current diverted by the automatic grounding conductive device exceeds 1 second and still cannot reach the safe current, the transformer PLC control device activates the overcurrent protector to close the transformer to achieve deep protection of the transformer. Provides a safe protection system for transformer leakage. The grounding conductive device of the invention is safe and reliable, and the implementation is cost-effective locally, and has better beneficial effects.

Description of drawings

Fig. 1 is a structural diagram of a transformer leakage current automatic grounding conductive device;

Figure 2 is a schematic circuit diagram of a transformer leakage protection system for real-time grounding conduction.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments, which are only used to explain the present invention and do not limit the protection scope of the present invention.

As shown in Figure 1, a transformer leakage current automatic grounding conductive device is connected to a transformer with a PLC control device 1 and a leakage current acquisition circuit 2 for use, wherein the PLC control device 1 is connected to the leakage current acquisition circuit 2, and the leakage current acquisition circuit 2 Connect the leakage current collection device 9, including a fixed bracket 31 and a grounding guide rod 32, the fixing bracket 31 is fastened at the bottom of the transformer casing, and the grounding guide rod 32 is rotatably grounded through the release motor 33 and the release device 34 Connected on the fixed support; and the release motor 33 is connected to the PLC control device of the transformer through the leakage current normally open switch 4 to obtain its work instruction; One end is connected to the fixed bracket 31 to rotate through the rotating shaft, the grounding guide rod 32 is overlapped on the top of the plug-in support rod 342, and the release motor 33 is connected to the plug-in support rod 342 to pull, and the release motor 33 is connected to the fixed bracket 35 through the sliding bracket. Sliding plug on the bracket 31.

In the above-mentioned embodiment, the grounding guide rod 32 is a two-stage structure made of an overturned connecting rod 321 and a flexible connecting rope 322. The overturned connecting rod 321 is used to be rotatably connected to the fixed bracket, and the other end of the flexible connecting rope 322 is a ground terminal, and the flexible connecting rope 322 is a long strip member made of one or more of steel cables, steel plates, and square steel.

In the above embodiment, the end of the flexible connecting rope 322 is also connected to the metal grounding ball 323, and the diameter of the metal grounding ball 323 is at least five times that of the flexible connecting rope.

In the above embodiment, the leakage current acquisition circuit 2 of the leakage protection system includes an inductance sensor and a current sensor; the leakage current acquisition device 9 includes at least three conductive members uniformly arranged around the outer shell of the transformer, and each conductive member is respectively connected to the leakage current. An inductance sensor and a current sensor of the current acquisition circuit 2.

In the above embodiment, the leakage current acquisition circuit 2 is also connected to the power supply 6 of the transformer through the overcurrent protector 5. When the leakage current of the automatic grounding conductive device 3 diversion exceeds one second and still cannot reach the safe current, the transformer PLC The control device activates the overcurrent protector to shut down the transformer.

In the above embodiment, the leakage current acquisition circuit 2 is also connected with the sound alarm device 7 and the flash alarm device 8 .

As shown in Figure 2, the transformer leakage protection system for real-time grounding conduction used in conjunction with the above-mentioned transformer leakage current automatic grounding conductive device includes a leakage current acquisition circuit 2 and a leakage current acquisition device 9 connected to the transformer PLC control device 1, And the automatic grounding conductive device 3 connected on the transformer shell, the automatic grounding conductive device 3 is connected to the leakage current acquisition circuit 2 of the transformer and the PLC control device 1 through the leakage current normally open switch 4 to obtain the diversion state signal; the leakage current acquisition circuit 2. It includes an inductance sensor and a current sensor; the leakage current acquisition device 9 includes at least three conductive members uniformly arranged around the outer shell of the transformer, and each conductive member is connected to the inductance sensor and the current sensor of the leakage current acquisition circuit 2 respectively. The leakage protection system, on the one hand, realizes real-time leakage current conduction grounding, and on the other hand, it sets up a protection circuit for leakage current leakage, that is, the automatic grounding conductive device is connected to the leakage current collection of the transformer through the leakage current normally open switch. The current diversion status signal is obtained from the circuit and the PLC control device, and the leakage current is connected to the power supply of the transformer through the overcurrent protector. When the leakage current of the automatic grounding conductive device cannot reach the safe current for more than one second, The transformer PLC control device activates the overcurrent protector to shut down the transformer to achieve deep protection of the transformer and provide a safe protection system for the leakage of the transformer. The leakage protection system of the invention is safe and reliable, has low cost of implementation and has good beneficial effects.

In the above embodiment, the leakage current acquisition circuit 2 is also connected to the power supply 6 of the transformer through the overcurrent protector 5. When the leakage current of the automatic grounding conductive device 3 diversion exceeds 1 second and still cannot reach the safe current, the transformer PLC The control device activates the overcurrent protector to shut down the transformer. A sound alarm device 7 and a flash alarm device 8 are also connected to the leakage current acquisition circuit 2 .

The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. Those skilled in the art can easily comprehend the spirit of the present invention based on the above-mentioned embodiments, and make different extensions and changes. But as long as it does not deviate from the spirit of the present invention, it is within the protection scope of the present invention.

Claims (6)

1. a kind of transformer leakage stream automatic earthing electric installation, it is characterised in that: be connected to PLC control device (1) and It is used on the transformer of leakage current Acquisition Circuit (2), wherein PLC control device (1) connection leakage current Acquisition Circuit (2), electric leakage Acquisition Circuit (2) connection leakage current acquisition device (9), including a fixed bracket (31) and a ground connection guide rod (32) are flowed, Gu Fixed rack (31) is fastened on the bottom position of transformer shell, and is grounded guide rod (32) and passes through release motor (33) and release dress Set being connected on fixed bracket (31) of (34) rotatable ground connection；And release motor (33) passes through leakage current normal open switch (4) It is connected on the PLC control device of transformer and obtains its work order；

Release device (34), including rotating arm (341) and plug support rod (342), rotating arm (341) one end passes through rotation Axis connection rotates on fixed bracket (31), and ground connection guide rod (32) is overlapped on above plug support rod (342), while discharging motor (33) connection plug support rod (342) pull, and discharge motor (33) and be connected to fixed bracket by sliding support (35) (31) plug is slided on.

2. a kind of transformer leakage stream automatic earthing electric installation according to claim 1, it is characterised in that: ground connection guide rod (32) the generally two-part structure made of overturning connecting rod (321) and flexible connection rope (322), overturning connecting rod (321) It is used for rotatably coupling on fixed bracket (31), other end flexible connection rope (322) is ground terminal, flexible connection rope (322) one of cable wire, steel plate, square steel or it is several made of elongated member.

3. a kind of transformer leakage stream automatic earthing electric installation according to claim 2, it is characterised in that: flexible connection The end of rope (322) is also connected with metallic ground ball (323), and the diameter of metallic ground ball (323) is at least the five of flexible connection rope Times.

4. a kind of transformer leakage stream automatic earthing electric installation according to claim 1, it is characterised in that: leakage current Acquisition Circuit (2) includes inductance sensor and current sensor；Leakage current acquisition device (9) includes the ambient envelope along transformer At least three conductive members being evenly arranged, the inductance that each conductive member is separately connected leakage current Acquisition Circuit (2) pass Sensor and current sensor.

5. a kind of transformer leakage stream automatic earthing electric installation according to claim 1, it is characterised in that: leakage current is adopted Collector (2) also connects the power supply (6) of transformer by overcurrent protective device (5), when automatic earthing electric installation (3) is led The leakage current of stream up to the time be more than transformer PLC control device starting over current protection when still cannot reach safe current within one second It protects device and closes transformer.

6. a kind of transformer leakage stream automatic earthing electric installation, feature according to claim 4 or 5 any one exist In: audible alarm unit (7) and flashing alarm device (8) are also connected in leakage current Acquisition Circuit (2).