JPS59161805A - Driving of transformer cooler - Google Patents

Abstract

PURPOSE:To achieve economical transformer cooling by a method wherein, when a load factor of the transformer is below the preset value, a cooler motor is driven by a speed control inverter and, when the load factor is over the preset value, the cooler motor is driven by the primary source of a source transformer. CONSTITUTION:The voltage of a source 1 is reduced by a source transformer 10 and supplied to a variable speed control inverter 2. Motors 5a, 7a of a cooler 4 are connected and changed to any one of an output side of the inverter 2 and the primary side of the transformer 10 by a power source switching over equipment 11. The judging part 13 of the load factor of a transformer 3, the instituting part 14 of the load factor, the speed directing part 15 and the source change directing part 16 are contained in a driving control equipment 12. The load factor of the transformer 3 is detected by a load factor detector 8 and put into the equipment 12. When the load factor is below the peset value of the setting part 14, the driving control of the motors 5a, 7a are performed by the inverter 2 and, when the load factor is over the preset value, the driving control is performed by the power source 1. With this constitution, energy-saving operation of a cooler is achieved and the driving of a transformer cooler with an inverter of economized capacity is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Techniques of the Invention 5) Field] The present invention relates to a method of operating a forced cooling transformer cooler.

[Technical background of the invention and its problems]

In recent years, for the purpose of energy saving, etc., the speed of the transformer cooling system is controlled by changing the speed of the transformer depending on the load or temperature of the transformer. Since then, methods have been implemented to reduce the power consumption of cooling equipment.
As a stop device, an inverter is generally used to change the power frequency and/or voltage of the cooler motor. This inverter valley-1
Since the ID transformer needs to be sized to accommodate the valley of the cooler motor that is operated when the load factor is 100,
For transformers with large cooler capacities, such as Otani Kashi transformers, the size of the inverter would be too large, which would increase the cost. This force will be explained with reference to FIG.

Fig. 1 shows an example of a conventional variable speed continuous cooling device, where ■ is the 1 source, 2rl is a variable speed control power supply device consisting of a variable frequency inverter or a variable pressure device; 3 is an oil-immersed transformer, 4 is a cooler for the transformer 3, and this cooler 4V includes a fan 5, a fan motor 5a, a radiator 6, a motor 7a for pop/pu 7, etc. Je, Shizukerante, Ruru. Reference numeral 8 denotes an oil temperature detection device for the transformer 3, such as an oil temperature detection device or a mainline thermal protection relay device. Instead of this, it is also possible to provide a load factor detection device such as a Psononog current transformer. 9 is a quick farting device.

The temperature or load factor of the transformer 3 detected by the detection device 8' (C) is input manually to the speed command table 9, and based on this, a command is issued to set the required speed.Speed command device According to the 90 directive, the inverter 3 converts the voltage and frequency from the power supply 1 into the voltage and frequency according to the temperature V or load factor and supplies the entire power.Thereby, the motor for the fan attached to the cooler 4 5a and pump motor 7
A is operated at a variable speed, and the heat radiator from the radiator 6 is controlled. The output from the inverter 3 becomes maximum when the negative rate is ioo %, and this determines the inverter's capacity. For this reason, if the number of coolers is large, such as a transformer, the inverter container will be large.

On the other hand, an example of the annual load factor of a transformer is shown in Figure 2. In this figure, the horizontal axis is the load factor of the transformer, and the vertical axis is the annual operating time and This is expressed as a ratio.There are about 5 hours in a year when the load factor exceeds 60%. By the way, the power required for the cooler is determined by the amount of heat generated by the transformer to be cooled, that is, the generated loss, so here, calculate the generated loss W inside the transformer when the load factor is 65%,
Let's compare it with that at 100% load.

W = Wx, +WN = p2-WLO+WN ・
・-(1) Here, W: Transformer generated loss at load factor p WL: Load loss at load factor p WLo: Load loss at rated load (load factor 100) WN: No-load loss p: Load factor generally ~' The ratio between VL o and ~VN is about 5:1 to IU:1 in the large-scale transformation word, so if it is set to 5:1, WLo = 5 WN...-(2) (2) can be transformed into (2) 1) Substituting into the formula, W=p2・10WN 10WN=(10p2+l)
WN... (3) If the load factor is 65,
Since p20.65, substitute this into equation (3) and get W = 3.1-Wpi --- (41 Also, if the load factor is 100%, p = 1.0, so this can be written as (
3) Substitute into the equation and get W=6. OvVN...-(51 From equations (4) and (5), when comparing the loss generated in the transformer when the load factor is 65chi and when the load factor is 100%, the temperature due to the loss generated in this transformer is The rise needs to be cooled by a cooler.In other words, the relationship between the required cooling capacity C of the cooler and the loss W generated by the transformer is as follows. . Should be 1.0 or more.

By the way, the core/and pump negative (
-'7 F torque Tid, the motor has a square torque characteristic that changes in proportion to the square of the rotational speed N, and the motor's '4
'lil power I) is proportional to the rotational speed N and torque T. That is, as shown in the formula below, the shaft power is proportional to the rotation speed.

tv,, N2 L■N-T 0cN3. ,,, (8J Also, the required power P of the motor is proportional to the shaft power, and the efficiency η'/(inversely proportional. Efficiency changes depending on the rotation speed and is not constant. Therefore, the rotation speed and the safety of the cooler motor 'The cod force relationship is 1 anti-conjecture.

On the other hand, the cooling capacity C of the cooler is approximately proportional to the rotation speed N.

0 ■N...(9) Therefore, +91
, +8) and (7), the required power P is 03
vv3 p c-: -oc-...aω η η .

Considering the above points, the required power P for the cooler is the pressure gJ
Fig. 3 shows an actual measurement example of the relationship between the required power of the transformer, which is significantly more than proportional to the loss of power νV. From Figure 3, the power required for the cooler is approximately 30% when the load factor is 65% compared to when the load is 100%.In other words, as the load factor becomes smaller, the power required for the cooler becomes significantly smaller. Become.

As mentioned above, in the current method of operating a cooler, the capacity of the inverter is determined by the power required for the cooler at 100% load, which is extremely uneconomical when the load factor of the transformer is low. It becomes.

[Purpose of the invention]

The invention has been made in view of the above points, and provides a method of operating a cooler for a transformer similar to that of a g-pile by reducing the excessive auxiliary input of the cooler and reducing the speed control inverter. [Summary of the Invention] In order to achieve the above objects, the present invention provides a method for operating a transformer cooler that detects the load factor of the transformer and controls the operation of the motor of the transformer cooler. How to transform the source pressure? It is connected to the secondary side of the transformer for I star and this transformer for speed control, which controls at least one of voltage or frequency. A switching connection to either the output side of the inverter or the primary side of the transformer is provided with a switching device, and the load factor of the transformer is set at a certain value. In the following, the motor is operated by a speed control inverter, and when the set value is exceeded, the motor is operated by the primary side power source of the power transformer.

[Embodiments of the invention]

Hereinafter, one embodiment of the method of operating a transformer cooler of the present invention will be described with reference to FIG.

10 is a power transformer that reduces the voltage of the power source 1; 11 is a dual-purpose speed control device; for example, a cooler 4 is connected to either the output side of the inverter 2 or the primary side of the power transformer 10;
a power supply switching device capable of connecting and switching the motors 5a and 7a;
12 is an operation control device, and the operation control device 12VC includes a load factor determining section 13 of the transformer 3, a load factor setting section 14, a speed 1.
A command section 15 and a power supply switching command section 16 are internally included.

8 is a load factor detection device. This load factor detection device can also detect the oil temperature or winding temperature, or by detecting electricity such as the actual load current.

Next, the operation of the present invention will be explained f. The load factor of the transformer 3 detected by the 6° load factor detection device 8 is inputted to the operation control device 12. Then, the determining unit 13 determines whether the load factor exceeds the set value of the load factor from the setting unit 14. If the set value is not exceeded, a speed command according to the load factor is given to the inverter 2 from the speed command unit 15, and the driving side # of the motor 5a and motor 7a of the cooler 4 is performed. If the load factor exceeds the set value, the power switching command section 16 issues a command to the power switching device 11 to connect the motors 5a and 7a of the cooler 4 to the primary side of the power transformer 10.

'j, that is, when the load factor exceeds the set value, the speed side X, l by the inverter 2 is not performed. This operating situation is shown in Fig. 5 (this will be explained further). , the vertical axis on the right is the required power of the cooler corresponding to the load factor, i.e., %B and OVc.
shows the value for For example, for the first shift with a negative aj$ setting, the load factor is set to 65%, which is considered to be rarely operated from curve A. The required power for the cooler is approximately 30 cm at the rated time based on curve B and the value on the vertical axis on the right side, and the corresponding Innovata valley j7tP2 can be set to 10
Compared to the case where the inverter capacity P+ corresponding to 0% load can be obtained, the inverter 2 can be made smaller due to the economical operation method with a significant reduction in energy consumption or OJ capacity [F]9. In addition, if the load factor exceeds the set value, the cold 41 unit will be operated 100 times, but the continuous operation time is predicted to be very short as seen from curve A, so the It can be considered that the excessive amount of electricity provided by Imayajisho can be ignored. That is, the cooler is operated as shown by curve C. Regarding the load factor setting value, since the load situation is considered to be different depending on the electric power station, the optimum value should be selected.

When the load factor of the +j'+J series exceeds 65%, the motors 5a and 7a of the fan 5 and pump 7 are connected to the primary side of the power transformer 10 by the power switching device 11. At this time, the transformation ratio of the 'g source transformer 10 is set to 2:1. For example, if the voltage of the power supply 1 is 400 V, and the rated human power voltage of the inverter is 200 V, it will be economical to use the inverter for 200 cm. and 7 must be able to be used at the voltage of power supply 1, so in this case, 4
00V rating. By doing so, the voltage of the inverter 2 is half the voltage of the power source 10, and the container can be reduced in size by about 30% when the transformer 3 is at 100% load.

It should be noted that the power transformer 10 is a ratio winding transformer.
The equivalent answer amount can be made small.

By the way, in the above embodiment, the power supply 1 is 400V.

If the primary power voltage of the inverter 2 is 200V, the output of the inverter 2 will generally be Ov to 200V, so if the set load factor is exceeded, the power transformer 10
With the switching of VC to the primary side, it is necessary to switch from 200 V to 400 V. At this point, since the characteristics of the cooler are not necessarily proportional to the power IE, the output of inverter 2 is 2 tlOV, and the inevitable depreciation is required.
In other words, the cold comb II tli r+ corresponding to the set load factor
Q or fJj −E 6 /]F ＋＋＜=vvs 4o
The case 6'/C where o v is marked 7Jfl is the 1'11 mu IJ characteristic quietness required when the input second finger 3 load and a half is 100 degrees, but not necessarily the q cooling performance. There is a possibility that a large sinus deficiency may occur. The method of stopping this surplus/deficiency f3:VJ will be explained with reference to FIG. 6 VC. Parts that are the same as those in FIG. 4 are indicated by serial numbers. In the 6th evil, ゛e7i L M2'r! j 17 VC towers 17a and 17b are provided,
This tag, aI, is set to the voltage at which the cooling power of the cooler at a load factor of 100% VC is reached.

When the set load factor is exceeded, by connecting the motor power supply of the cooler from the output side of the inverter 2 to this tag 17a of the power transformer 17, it is possible to provide a sufficient cooling capacity without excess or deficiency. can. In addition, in the above embodiment, the comparison between the detected value and the set value as the load factor is described.
this? ! 1.In the case of ``transformation degree or relative softness of tonne pressure'', it is included in the comparison of load factors. In areas where the load factor is lower than the set load factor, where there is a high possibility that the equipment will be operated, speed control is performed using a single noverter according to changes in the load factor, and if the set load factor is exceeded, the power transformer is Since the motor is operated according to the present invention, it is possible to obtain a method of operating a cooler for a transformer that achieves energy-saving operation of the cooler and saves the capacity of the inverter for variable speed operation.

[Brief explanation of the drawings] Fig. 1 is an explanatory diagram showing an example of a conventional variable speed transmission device for a transformer cooler, and Fig. 2 is a curve diagram showing an example of the annual load factor of a transformer. , Fig. 3 is a characteristic diagram showing an actual measurement example of transformer load factor and cooler required power, Fig. 4 is an explanatory diagram showing an example of an uninvented method of operating a transformer cooler, and Fig. 45 is a conventional method. FIG. 6 is an explanatory diagram showing another embodiment of the present invention. 1°・Power supply 2・・Inverter 3・・Oil-immersed transformer 4・・Cooler 5・Guar 15. a..Motor 6..Heat radiation 6 7..Bonga a..Motor 8.Matachi device 9..Speed command device 1o..Electric W transformer 11..Power switching device 12..Driving control device 13 ...judgment section
14... Rectangle setting part 15... Speed command part 16...
Area source switching command unit 17 ...Tapped transformer 17
a, 17b...Tag agent Patent attorney Nori Chika Kei
Yu (1 person) Figure 1 Figure 2 (Throat) (Childhood Ode to Bentai Bean) - Ra Figure 3 Figure 5 (L/,) → Figure 4 Figure 5 Tokuzheng Pei (- /;) −

Claims (1)

[Claims] (1) In a method for operating a transformer cooler that detects the load factor of the transformer and controls the operation of the motor of the transformer cooler, a transformer, and a dual-use inverter connected to the secondary side of the power transformer and adjusting at least one of voltage or frequency;
a power supply switching device that selectively connects the motor of the cooler to either the output side of the inverter or the primary side of the power transformer, and when the load factor of the transformer is below a certain set value, the motor is A method for operating a cooler for a transformer, characterized in that the motor is operated by the primary side source of the power transformer when the set value is exceeded. (2) The ratio of the primary voltage of the power transformer to the secondary voltage is 2.
: 1. A method for operating a transformer cooler according to claim 1, wherein: 1. (A method for operating a transformer cooler according to claim 1, characterized in that 31 is a power transformer r autotransformer. (4) The power transformer is a tapped transformer. , set the tap voltage value to at least a value that can produce electric power at the cooler station 9 at a load factor of 100%, and when the load factor of the transformer is below a certain set value, the motor is operated by the speed control inverter V, and when the set value is exceeded. (5) A method for operating a transformer cooler according to claim 1, in which the motor is connected to the tap of the power transformer when the load factor is changed to the temperature of the transformer. 5. The method of operating a transformer cooler according to claim 1, wherein the detection is performed by detecting at least one of the amounts of electricity.