CN205507574U - Transformer automatically cooling system - Google Patents

Abstract

The utility model proposes a transformer automatic cooling system, which includes a main circuit, a control circuit, an emergency backup circuit and a temperature measuring device; The cooler is connected; in the control circuit, the automatic switch module and the coil of the contactor are connected in series and then connected to both ends of the power supply; in the emergency backup circuit, the working power supply passes through the second fuse and the backup switch in sequence, and then is connected to the backup cooler ;The automatic switch module includes a stop switch, a start switch, and the second normally open node of the contactor, and the stop switch and the auxiliary contact of the contactor are connected in series; the temperature measuring device is used to measure the oil temperature of the transformer, and output the measurement result to the stop Control terminal for switch and start switch. The utility model can control the automatic start and stop of the cooler in real time, reduce the power consumption of the station, and at the same time avoid the tripping and outage accident of the transformer when the cooler circuit fails.

Description

A Transformer Automatic Cooling System

technical field

The utility model relates to the field of transformers, in particular to an automatic cooling system for transformers.

Background technique

Because the transformer will generate a lot of heat during use, it needs to be equipped with a cooling device. The existing 35kv transformer is mostly cooled by oil-immersed self-cooling method, but for the state of continuous high temperature and high load in summer heat, this cooling method is often It is difficult to meet the cooling needs of the transformer. Therefore, at present, most 35kV substations are equipped with external fans to assist the transformer in cooling, and the cooling effect is remarkable.

As shown in Figure 1, it is the traditional cooling system wiring method in the prior art. The three-phase alternating current flows out through the A, B, and C terminals, and supplies power to the cooler after passing through the fuse FU1 and the switch K. Among them, FU1 controls the circuit. Overcurrent fusing, switch K controls the start and stop of the external fan. It can be seen from Figure 1 that the traditional cooling system circuit connection method can only be started and stopped manually, which leads to two defects: (1) when the temperature When the cooling device is reduced to no need for auxiliary cooling, the cooling device cannot automatically shut down, resulting in excessive power consumption in the substation; (2) When the cooling device fails, if the maintenance personnel fail to find the problem in time, they will rush to the scene to deal with it within the specified time , will cause the transformer oil temperature to rise, and even cause the transformer to trip and stop, reducing the operational reliability of the power system.

Utility model content

The utility model overcomes the deficiencies in the prior art, and provides an automatic cooling system for a transformer that can control the automatic start and stop of the transformer cooling device.

In order to solve the above technical problems, the technical solution adopted by the utility model is: an automatic cooling system for transformers, which is characterized in that it includes a main circuit, a control circuit, an emergency backup circuit and a temperature measuring device. After the first fuse, the first normally open node of the contactor is connected to the cooler; in the control circuit, the automatic switch module and the coil of the contactor are connected in series and then connected to both ends of the power supply; the emergency backup circuit Among them, the working power supply is connected to the standby cooler after passing through the second fuse and the standby switch in turn; the automatic switch module includes a stop switch, a start switch, and the second normally open node of the contactor, and the stop switch and the The auxiliary contact of the contactor is connected in series; the temperature measuring device is used to measure the oil temperature of the transformer, and the measurement result is output to the control terminal of the stop switch and the start switch; the stop switch and the start switch It is a normally open switch controlled by temperature, and the control terminals of the stop switch and the start switch are connected with the temperature measuring device.

In the automatic switch module, the start switch is connected in parallel to both ends of the auxiliary contact of the contactor KM1.

In the automatic switch module, the start switch is connected in parallel to both ends of the circuit formed by the stop switch and the auxiliary contact of the contactor in series.

In the above-mentioned automatic cooling system for transformers, when the oil temperature of the transformer rises above n, the stop switch is closed; when the oil temperature of the transformer rises above m, the start switch is closed, and n is The temperature return value of the transformer, the m is the temperature setting value of the transformer, and the temperature setting value m is greater than the temperature return value n.

In the aforementioned automatic cooling system for transformers, when the oil temperature of the transformer is higher than the maximum set temperature H of the system, the backup switch is automatically closed and remains closed until manually restored.

The automatic cooling system for a transformer further includes an emergency control circuit, in which, after the backup control switch is connected in parallel with the second normally open node of the second contactor, it is connected in series with the coil of the second contactor Both ends of the power supply; the backup switch is the first normally open node of the second contactor, the backup control switch is a normally open switch with a set closing temperature of H, the control terminal of the backup control switch is connected to the temperature measurement The device is connected.

The above-mentioned automatic cooling system for a transformer also includes a thermal relay FR, the heating element of the thermal relay FR is connected in series in the main circuit, and the normally closed contact of the thermal relay FR is connected in series in the main circuit of the control circuit. in the circuit.

Compared with the prior art, the utility model has the following beneficial effects: (1) The cooler can be automatically started and stopped in real time according to the temperature of the transformer, and the automatic cooling function of the transformer can be realized without manual operation, and the start and stop function of the cooler can be fully automated; and , when the auxiliary cooling is not needed, the cooler can be shut down in time to reduce the power consumption of the station; (2) When the cooler circuit fails, the spare cooler can be automatically started, so that the transformer oil temperature will not continue to rise, avoiding The possibility of transformer tripping and outage, or high temperature damage improves the reliability of power system operation.

Description of drawings

Fig. 1 is the wiring method of cooler in the prior art;

Fig. 2 is the first embodiment of a transformer automatic cooling system of the present invention;

Fig. 3 is a second embodiment of a transformer automatic cooling system of the present invention.

detailed description

In order to better understand the substantive content of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 2, the first embodiment of the present utility model is: a transformer automatic cooling system, including a main circuit, a control circuit, an emergency backup circuit and a temperature measuring device (not shown in the figure). In the main circuit, the three-phase alternating current flowing out of the terminal ABC of the three-phase AC working power supply passes through the first fuse FU1 in turn, and the first normally open node of the contactor KM1 is connected to the cooler M1 after that; in the control circuit, the terminal A in turn After the fuse FU2, the stop switch K1, the auxiliary contact of the contactor KM1 and the coil QM of the contactor KM1 are connected to the terminal B, the start switch K2 is connected in parallel to the stop switch K1 and the auxiliary contact of the contactor KM1 is formed in series. Both sides of the circuit; in the emergency backup circuit, the working power is connected to the backup cooler M2 after passing through the second fuse FU2 and the backup switch K in turn.

Wherein, the temperature measuring device is installed on the transformer, and its signal output terminal is connected with the control terminal of the stop switch K1 and the start switch K2, and is used to measure the oil temperature of the transformer, and output the measurement result to the stop switch and the start switch the control terminal. The stop switch K1 and the start switch K2 are normally open switches for temperature control, and their control terminals are connected to the signal output terminals of the temperature measuring device. When the temperature signal received by the control terminals of the stop switch K1 and the start switch K2 is higher than its own setting When the temperature is turned off, the corresponding switch will be closed under the control of its own control terminal, otherwise, it will always be in the open state. Wherein, the closing temperature of the stop switch K1 is set as the temperature return value n of the transformer, and the closing temperature of the starting switch K2 is set as the temperature setting value m of the transformer. Among them, the meaning of the temperature setting value m is: when the temperature of the transformer rises greater than m, the cooler should start to work to assist in cooling the transformer, so as to prevent the temperature of the transformer from being too high, and the meaning of the temperature return value n is: when the auxiliary cooling of the cooler When cooling reduces the temperature of the transformer to less than n, the cooler should stop working, and the system can stop auxiliary cooling to save energy. It can be known that m>n.

In addition, the signal output terminal of the temperature measuring device is also connected to the control terminal of the standby switch K. When the transformer oil temperature measured by the temperature measuring device rises to the fault temperature H, the control terminal of the standby switch K controls the standby switch K to close. When the transformer oil temperature rises to the temperature setting value m and does not drop, but continues to rise to H, it indicates that the main circuit or control circuit of the transformer automatic cooling system in this embodiment fails. At this time, the control terminal of the standby switch K Start, make the standby switch K close, then the standby cooler M2 starts, so that the transformer oil temperature will not continue to rise, avoiding the possibility of transformer tripping, shutdown, or high temperature damage, and improving the operational reliability of the power system.

Wherein, the model of the contactor KM1 may be CJ16B-63.

In addition, the transformer automatic cooling system of this embodiment further includes a thermal relay FR, which is arranged between the main contact of the contactor KM1 and the cooler in the main circuit, and is used for overheating protection of the main circuit.

The working process of the transformer automatic cooling system of the present embodiment is as follows:

(1) The transformer starts to work, the temperature is low, the stop switch K1 and the start switch K2 are both off, and the cooler does not work;

(2) As the working time becomes longer, the temperature of the transformer gradually rises to be greater than the temperature return value n, the control terminal associated with the transformer temperature controller closes the stop switch K1, and keeps the start switch K2 off;

(3) The temperature of the transformer continues to rise. When the temperature reaches the set value m, the start switch K2 is closed. At this time, the coil QM1 of the relay KM1 is charged, and its main contact and auxiliary contact are both closed. The control circuit forms a self-locking, the main The circuit is connected, the cooler starts, and the auxiliary cooling starts;

(4) The temperature of the transformer begins to drop. When the temperature drops between m and n, the start switch K2 is turned off, but because the relay KM is in a self-locking state, the cooler will not stop cooling;

(5) When the temperature continues to drop below n, the stop switch K1 is disconnected, the coil QM of the relay KM1 loses power, the main circuit is disconnected, and the cooler stops cooling;

(6) After the cooler stops cooling, the temperature of the transformer continues to rise, and the next round of automatic cooling will start.

If the cooler M1 fails, or the circuit where the cooler fails to operate, the transformer oil temperature will continue to rise. When the transformer oil temperature rises to the fault temperature H set by the system, the standby switch K will be activated by the control terminal. Closed and held closed, the backup cooler activates, cooling the transformer until manually restored by maintenance personnel.

As shown in Figure 3, it is the second embodiment of the utility model, namely: a transformer automatic cooling system, including a main circuit, a control circuit, an emergency backup circuit, an emergency control circuit and a temperature measuring device (not shown in the figure) . In the main circuit, the three-phase alternating current flowing out from terminals A, B, and C of the three-phase alternating current working power supply passes through the first fuse FU1 in turn, and the first normally open node of the contactor KM1 is then connected to the cooler M1; in the control circuit, The terminal A passes through the stop switch K1, the auxiliary contact of the contactor KM1, the coil QM of the contactor KM1, and then connects to the terminal B, and the start switch K2 is connected in parallel to both sides of the auxiliary contact of the contactor KM1; the emergency backup circuit In the circuit, the working power supply passes through the fuse FU2 in turn, and then the first normally open node of the second contactor KM2 is connected to the standby cooler M2; in the emergency control circuit, after the second normally open node of the second contactor KM2 is connected in parallel with the switch K3 After being connected in series with the coil QM2 of the second contactor KM2, one end is connected to terminal A, and the other end is connected to terminal B.

Wherein, the temperature measuring device is installed on the transformer, and its signal output terminal is connected with the control terminals of the stop switch K1, the start switch K2, and the backup control switch K3 for measuring the oil temperature of the transformer, and outputting the measurement result to the stop switch and the control terminal of the start switch. The stop switch K1 and the start switch K2, and the standby control switch K3 are normally open switches for temperature control, and their control terminals are connected to the signal output terminals of the temperature measuring device. When the control terminals of the stop switch K1 and start switch K2 receive a high temperature signal When the closed temperature is set by itself, the corresponding switch will be closed under the control of its own control terminal; otherwise, it will always be in the open state. Among them, the closing temperature of the stop switch K1 is set as the temperature return value n of the transformer, the closing temperature of the starting switch K2 is set as the temperature setting value m of the transformer, and the closing temperature of the standby control switch K3 is set as the fault temperature H of the transformer , among them, H>m>n, technicians can determine the values of m, n and H according to the field working environment and working parameters of the transformer.

The normal work flow of this embodiment is the same as that of the first embodiment, and the difference from the first embodiment is the fault work flow: if the cooler M1 breaks down, or the circuit breaks down so that the cooler cannot operate, the transformer oil temperature will continue When the transformer oil temperature rises to the fault temperature H set by the system, the backup control switch K3 is closed, and the coil of the second contactor KM2 is energized, then the first normally open node and the second normally open node of the second contactor KM2 When the node is closed, the backup cooler M2 starts to cool the transformer, and the oil temperature of the transformer drops. Although the backup control switch K3 is disconnected, the second contactor is in a self-locking state, and the backup cooler M2 will keep cooling the transformer. The possibility of transformer tripping and outage due to rising oil temperature, or high temperature damage, improves the operational reliability of the power system. The standby cooler can be manually stopped by maintenance personnel after repairing the main circuit.

In addition, a transformer automatic cooling system of this embodiment also includes a thermal relay FR, whose model can be TGR36-45, the heating element of the thermal relay is connected in series between the contactor KM and the cooler in the main circuit, and the normally closed contacts are connected in series In the main circuit of the control circuit, it is used to protect the cooler from overheating.

In addition, the transformer automatic cooling system of this embodiment also includes an air switch K, the model of which can be DZ47-63, and the air switch is connected in series in the circuit before the three-phase alternating current enters the main circuit, and is used to overhaul the automatic start-stop circuit. flow, overload protection.

Therefore, a transformer automatic cooling system of the present invention, by being associated with the transformer oil temperature, can realize the automatic start and stop of the cooler in real time according to the transformer temperature, realize the automatic cooling function of the transformer, and realize the complete start and stop function of the cooler without manual operation. Automatic; and, when the auxiliary cooling is not needed, the cooler can be shut down in time to reduce the power consumption of the station; at the same time, when the cooler circuit fails, the backup cooler can be automatically started, so that the transformer oil temperature will not continue to rise , to avoid the possibility of transformer tripping and outage, or high temperature damage, and improve the operational reliability of the power system.

The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings, but the present utility model is not limited to the above-mentioned embodiments. Make various changes below.

Claims (7)

1. a transformator automatic cooling system, it is characterised in that include main circuit, control circuit, emergency power circuit and temperature measuring equipment, in described main circuit, working power is connected with cooler successively after the first fuse, the first normally opened node of catalyst；

In described control circuit, the coils connected in series connection of automatic switch module and described catalyst is followed by both ends of power；

In described emergency power circuit, working power is connected with standby cooler successively after the second fuse, backup circuit breaker；

Described automatic switch module includes the second normally opened node of shutdown switch, activate switch and described catalyst, the auxiliary contact series connection of described shutdown switch and described catalyst；

Described temperature measuring equipment is for the oil temperature of measuring transformer, and measurement result exports the control end of described shutdown switch and described activate switch；Described shutdown switch and described activate switch are temperature controlled normal open switch, and described shutdown switch is connected with described temperature measuring equipment with the control end of described activate switch.

A kind of transformator automatic cooling system the most according to claim 1, it is characterised in that in described automatic switch module, described activate switch is connected in parallel on the auxiliary contact two ends of described catalyst KM1.

A kind of transformator automatic cooling system the most according to claim 1, it is characterised in that in described automatic switch module, described activate switch is connected in parallel on the circuit two ends that the auxiliary contact series connection of described shutdown switch and described catalyst is formed.

A kind of transformator automatic cooling system the most according to claim 1, it is characterized in that, when the oil temperature of transformator is increased to more than n, described shutdown switch closes, when the oil temperature of transformator is increased to more than m, described activate switch closes, and described n is the temperature return value of transformator, described m is the desired temperature of transformator, and described desired temperature m is more than temperature return value n.

A kind of transformator automatic cooling system the most according to claim 1, it is characterised in that when the oil temperature of transformator is more than system highest setting temperature H, described backup circuit breaker automatically closes and is kept closed until manually recovering.

A kind of transformator automatic cooling system the most according to claim 5, it is characterized in that, also include emergency control circuit, in described emergency control circuit, after standby the second normally opened node parallel connection controlling switch and the second catalyst, it is connected to both ends of power with the coils connected in series of the second catalyst；Described backup circuit breaker is the first normally opened node of the second catalyst, and the described standby switch that controls is for setting the closed temperature normal open switch as H, and the described standby control end controlling switch is connected with described temperature measuring equipment.

A kind of transformator automatic cooling system the most according to claim 1, it is characterized in that, also including that thermorelay FR, the heater element of described thermorelay FR are connected in described main circuit, the normally closed interlock of described thermorelay FR is connected in the main circuit of described control circuit.