JPH0346964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Transformers generate noise due to the magnetostrictive phenomenon of the iron core and can therefore be a source of noise pollution. Conventionally, in order to prevent this, it has been widely practiced to provide a soundproof wall to the transformer or provide a soundproof wall around the transformer. However, either method has disadvantages such as significantly increasing the size, weight, and price of the transformer, and requiring a large space for installing the transformer. Furthermore, when applying these measures to an existing transformer, there were problems such as a large amount of cost and a long period when the transformer was out of service.

This invention was made in order to solve the drawbacks and problems of the above-mentioned conventional ones.A main transformer and an auxiliary transformer are installed side by side, so that only the main transformer is operated at all times, and the auxiliary transformer is operated during noise control. By connecting the transformer in series with the main transformer, the purpose is to lower the magnetic flux density of the main transformer core and reduce noise.

In general, noise regulations vary depending on the time of day, and the regulation value usually differs by about 10 phona between daytime and nighttime. On the other hand, the load factor of transformers is very low at night, and substation transformers have a load factor of 20
%~30% is normal. This invention focuses on these two facts. In other words, an auxiliary transformer is installed separately from a main transformer with a normal structure, and during times when noise regulations are high, such as during the day, only the main transformer is used and operated as a normal transformer. During times when noise regulation values are low, such as at night, an auxiliary transformer is connected in series with the main transformer to lower the magnetic flux density in the main transformer's core, thereby reducing noise. In such usage conditions, the load on the transformer is low as described above, so the current capacity of the auxiliary transformer may be small, and the cost for providing the auxiliary transformer is small. In addition, even if the main transformer is already installed, noise reduction work (auxiliary transformer installation work) can be performed separately from the main transformer, so the main transformer outage period for noise reduction is the shortest. nothing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A transformer device according to an embodiment of the present invention will be described below with reference to the drawings. In the figure, 1 is a main transformer, 1a and 1b are the primary and secondary windings of this main transformer 1, and 2 is an auxiliary transformer installed in parallel with the main transformer 1, with a primary winding 2a and a secondary winding. The secondary winding 2b is connected in series with those 1a and 1b of the main transformer 1, respectively. 3 and 4 are each winding 2 of the auxiliary transformer 2
5 is a voltage stabilizing winding connected in parallel to the secondary winding 1b of the main transformer 1 via a third switch 6. This is provided to stabilize the voltage sharing between the main transformer 1 and the auxiliary transformer 2.

Next, the operation of the transformer device in one embodiment of the present invention configured as described above will be explained.

First, the main transformer 1 is normally used in the same state as a normal transformer by operating the first and second switches 3 and 4 to close and the third switch 6 to open. Next, during times when noise is restricted, such as at night, the first and second switches 3 and 4 are opened, and the third
The switches 6 are respectively closed to induce voltage in the auxiliary transformer 2 and the voltage stabilizing winding 5, thereby reducing the magnetic flux density of the main transformer 1 and
and stabilize the voltage sharing of the auxiliary transformer 2. In this way, the auxiliary transformer 2 and the switches 3, 4,
The effect of achieving a large noise reduction can be obtained at a small cost of providing Class 6. In addition, as a secondary effect, during low-noise operation, the core loss of the main transformer 1 is also greatly reduced, so although the loss of the auxiliary transformer 2 increases, the overall loss may also decrease depending on the size of the load. This also improves the economy of operation.

Furthermore, considering the data showing the relationship between noise, 10
To reduce the phone noise, the magnetic flux density needs to be reduced by about 20%. Therefore, the shared voltage of the auxiliary transformer 2 should be about 25% (1/1+0.25=0.8) of the main transformer. If the current capacity of the auxiliary transformer 2 is set to 30% of that of the main transformer, the auxiliary transformer 2 will only require a small amount of 0.25×0.3=0.075, or 7.5%, of the main transformer 1.

As described above, according to the present invention, the main transformer and the auxiliary transformer are installed in parallel, and only the main transformer is operated at normal times, and the auxiliary transformer is connected in series with the main transformer during noise control, and the voltage is stabilized. By stabilizing the shared voltage between the main transformer and the auxiliary transformer using the windings, it is possible to provide a transformer device having an excellent noise prevention effect.

[Brief explanation of drawings]

The figure is a wiring diagram showing the configuration of a transformer device in an embodiment of the present invention. In the figure, 1 is the main transformer, 2 is the auxiliary transformer,
3 and 4 are first and second switches.

Claims (1)

[Claims] 1 A main transformer, and an auxiliary transformer whose primary and secondary windings are connected in series to the primary and secondary windings of the main transformer, respectively, and connected in parallel to the primary and secondary windings of the auxiliary transformer, respectively. a voltage stabilizing winding provided in the auxiliary transformer and having both ends connected in parallel to the secondary winding of the main transformer via a third switch; A transformer device characterized by comprising: