JPS6150314A - Controlling method for cooling of transformer - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a cooling device by a method wherein the smallest number of cooling devices of a transformer suited for the temperature condition of the transformer are operated. CONSTITUTION:A temperature controlling device 23 compares the preset reference temperature value of a transformer oil 6 with an actual temperature signal 16, and it outputs a signal 17 indicating the number of oil-feeding pumps to a oil-feeding pump controlling device 24 when the difference of the above-mentioned comparison exceeds the tolerance limits. When the actual temperature signal 16 is higher than the reference temperature value, the signal of the number of oil-feeding pump 8 is increased, and the number of oil-feeding pump 8 is decreased when the actual temperature signal 16 is lower than the reference temperature value. An oil-feeding pump controlling device 24 determines the number of oil-feeding pump 8 in operation in accordance with the oil- feeding pump number signal 17, the device 24 selects the oil-feeding pump 8 to be operated or those to be stopped in accordance with the operation pattern determined in advance by the preceding machine, the following machine and the like, and the device 24 controls the number of the oil-feeding pump 8. As a result, the circulating quantity of the transformer oil 6 passing through an oil-feeding pipe 7 is controlled by stage and, at the same time, the temperature of the transformer oil 6 is also controlled by stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transformer cooling control method that adjusts the amount of cooling according to temperature changes.

[Technical background of the invention and its problems 1 In recent years, with the increase in the number of transformers, multiple windings are often used to take advantage of the advantages of reducing installation space and simplifying maintenance and inspection. The capacity of cooling equipment is also increasing.

Since many types of loads are connected to a multi-winding transformer, a cooling device that can follow diversifying load change patterns is required.

Conventionally, the cooling capacity of a transformer's cooling system is adjusted by detecting the load connected to the transformer, regardless of the transformer's temperature, by detecting the opening/closing state of the circuit breaker or actual load detection, and starting the corresponding number of cooling devices. , a stopping method is used.

In this method, since the relationship between the transformer temperature and the load is not close, it often leads to increased power consumption of the cooling device due to excessive cooling and deterioration of the transformer due to temperature changes.

An example of a conventional method for controlling cooling of a transformer is shown in FIG.

In Figure 2, 1 is a transformer with 3 windings on the load side, 2
．． 3.4 is the load side that connects different loads.15
disconnector, 5 is a power supply side breaker, 6 is transformer oil, 7 is an oil pipe, 8 is an oil supply pump, 9 is an oil cooler, 10 is a cooling water supply pipe, 11 is a cooling control device, 12 is a power supply side breaker 13 is a load-side breaker signal, and 14 is an oil pump start/stop signal.

In Fig. 2, when only the power supply side breaker 5 is closed, a no-load loss occurs in the transformer 1, the temperature of the transformer increases, and at the same time, the temperature of the transformer oil 6, which is the cooling medium, also increases. .

Therefore, the closing operation of the power supply side breaker 5 is inputted to the cooling control device 11 as the power supply side breaker signal 12, and a start/stop signal 14 is sent to a predetermined number of oil feed pumps 8 to select the oil feed pump 8. Activate it.

In this case, the water supply pipe 1 is
0 is passing the cooling water of all the oil coolers 9, and therefore more cooling water than the required amount is being passed.

In addition, the cooling capacity of each oil pump 8 is often selected to be the same capacity in preparation for switching between the regular machine and the standby machine, but in this case, the number of oil pumps 8 is determined based on the total load cooling capacity of the transformer. If the number of oil feed pumps 8 is decreased, the capacity of each oil feed pump 8 will increase and there is a risk that the temperature difference of the transformer will increase due to the inability to follow small load changes.On the other hand, if the number of oil feed pumps 8 is increased, the cooling capacity will increase. Adjustment is possible to some extent, but each oil pump 8
The disadvantage is that the selection control becomes complicated.

Next, in addition to the power supply side breaker 5, the negative side breaker 2.3.
4 is closed, a load loss occurs in the transformer 1 in addition to a no-load loss, and the concentration of the transformer oil 6 increases.

In this case, the closing operation of the load-side circuit breaker 2.3.4 is set as the load-side circuit breaker signal 13, and the cooling section control device! 11, and in the cooling control device 11, each load-side circuit breaker 2.
3. An oil pump start/stop signal $14 is sent to the number of oil pumps 8 predetermined by the maximum load passenger in step 4, and the oil pumps 8 are selectively activated.

In this case, since cooling is performed by a fixed oil pump 8 regardless of changes in the connected load, the cooling effect cannot follow the load loss of the transformer, resulting in excessive cooling, which only affects the transformer due to temperature differences. Therefore, more power than necessary is consumed by operating the oil pump and passing cooling water to the oil cooler.

For this reason, a method is also used in which the power of each of the load-side windings of the transformer is detected and inputted to the cooling control device f11, and the oil pump is started and stopped according to the load state.
In this case, since the cooling control is performed by predicting the temperature rise due to the load, control with safety in mind is required, and the above problem cannot be satisfactorily solved.

[Object of the invention] The present invention detects the temperature of a transformer, controls the amount of cooling according to the detected temperature, thereby reducing the power consumption of the cooling device and preventing deterioration of the transformer. The purpose of the present invention is to provide a rational cooling control method for a transformer that can simplify cooling control by eliminating signal communication with external devices such as circuit breakers and power detectors connected to the transformer.

[Summary of the Invention] The present invention is a transformer cooling control method that circulates and cools transformer oil via a plurality of oil coolers, in which the oil temperature of the transformer is detected and the temperature difference between the oil temperature and a set temperature is detected. When the temperature exceeds the predetermined temperature range, the oil coolers are operated or stopped one by one one by one, and when the temperature difference between the oil temperature and the set temperature is within the predetermined temperature range, the operation is stopped according to the temperature difference. The amount of cooling water in the oil cooler is increased or decreased, thereby simplifying the cooling system, reducing temperature changes in the transformer, and reducing power consumption of the cooling device.

[Embodiment of the Invention] An embodiment of the present invention is shown in FIG. 1. In FIG. 1, 15 is a cooling water control device, 16 is an actual temperature signal, 17 is an oil pump number signal, and 18 is an oil pump. Operation stop signal, 19 is a cooling water adjustment signal, 20 is a cooling water supply valve opening signal, 21 is a cooling water supply valve that adjusts the amount of cooling water, 2
2 is a temperature detector, 23 is a temperature control device, 24 is an oil feed pump control device, and the others are the same as in the conventional FIG. 2.

When the power-side circuit breaker 5 closes, the transformer 1 is closed even when the transformer 1 is in a no-load condition, and even when any of the load circuit breakers 2.3.4 is closed and the transformer 1 is in a loaded condition. The temperature of the transformer 1 changes due to the no-load loss and the load loss, and at the same time, the temperature of the transformer oil 6, which is the cooling medium of the transformer 1, also changes.

The temperature of the transformer oil 6 changes according to changes in the load connected to the load-side circuit breaker 2.3.4,
The actual temperature signal 16 is detected by the temperature control WJ@
1123.

The temperature control device 23 compares the preset reference temperature value of the transformer oil 6 with this actual temperature signal $16, and if the difference exceeds the set tolerance range, the oil feed pump number signal 17 is controlled to control the oil feed pumps. If the actual temperature signal 16 rises above the reference temperature value, the number signal of the oil feed pumps 8 is increased, and if the actual temperature signal 16 falls below the reference temperature value, the number of oil feed pumps 8 is increased. Reduce or increase the signal.

The oil pump control device 24 determines the number of oil pumps 8 to be operated according to the oil pump number signal 17, and determines the number of oil pumps 8 to be operated or stopped according to a predetermined operation pattern between the preceding machine and the following machine. 8 is selected to control the number of operating oil pumps 8.

As a result, the amount of transformer oil 6 circulated through the oil pipe 7 is controlled in stages, and the temperature of the transformer oil 6 is also controlled in stages.

Furthermore, in response to a temperature change in the transformer oil 6 within the range of cooling amount per oil pump 8, a cooling water adjustment signal 19 is sent from the temperature control device 23 to the cooling water control 2IllA position 15. The cooling water vJIIl device 115 sends a cooling water supply valve opening degree signal 20 to the cooling water supply valve 21 of the oil cooler 9 connected to the oil feed pump 8 that is in operation, and adjusts the opening degree thereof.

As a result, the cooling water supply pipe 1 that supplies the oil cooler 9
The temperature of the transformer oil 6 is finely adjusted by adjusting the amount of cooling water from 0 and changing the cooling capacity of the oil cooler 9.

A temperature control system is installed to prevent sudden temperature rises in the transformer oil 6 due to sudden changes in the load on the transformer 1! At f23, the temperature change rate, which is the temperature change range for a constant FR, is monitored, and if the temperature change rate exceeds the predetermined temperature change rate, the oil feed pump 8 is operated by increasing the oil feed pump number signal 11 in advance. The number of transformers is increased and the amount of cooling is increased before the transformer 1 reaches abnormal temperature.

By repeating these controls, the transformer oil 6
The temperature of the transformer 1 is maintained within a constant temperature range defined by the temperature control device 23, and the temperature of the transformer 1 is also maintained within a constant range.

The above embodiments are for oil circulation cooling type transformers, but the present invention can be achieved by adjusting the amount of cooling water in the case of the water circulation cooling type and by controlling the number of operating fans in the case of the fan air cooling type. Applicable.

Further, the present invention is applicable not only to a multi-winding transformer but also to a group of transformers when all the transformers share the same cooling device.

[Effects of the Invention] As explained above, according to the present invention, the transformer cooling device is operated with the minimum number of units depending on the temperature state of the transformer, which not only reduces the power consumption of the cooling device. , keeping the temperature of the transformer constant to prevent deterioration of the transformer,
Furthermore, it is possible to realize a rational transformer cooling control method that separates the transformer cooling control from equipment conditions other than the transformer, and allows the cooling system to be made into a cylinder.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a system diagram showing an example of a conventional transformer cooling control method. 1...Transformer 2.3.4...Load side breaker 5...Power side breaker 6...Transformer oil, 7...Oil pipe 8...Oil pump, 9. ... Oil cooler 15 ... Cooling water control device 21 ... Cooling water supply valve 22 ... Temperature detector 23 ... Temperature control device 24 ... Oil pump tillIIl device (7317)
Agent Patent attorney Noriyuki Chika (one idiot) Figure 1 β Figure 2

Claims (1)

[Claims] In a transformer cooling control method that circulates and cools transformer oil via multiple oil coolers, the oil temperature of the transformer is detected,
When the temperature difference between the oil temperature and the set temperature exceeds the predetermined temperature range, the oil coolers are operated or stopped one by one, and when the temperature difference between the oil temperature and the set temperature is within the above predetermined temperature range. A method for controlling cooling of a transformer, characterized in that the amount of cooling water in an operating oil cooler is increased or decreased in accordance with the temperature difference.