JPS61177123A - Feeder circuit for refrigerating container - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a power supply for refrigerated containers in which, for example, a plurality of refrigerated containers are connected and each refrigerated container is supplied with electric power to two types of different voltage receptacles provided in each refrigerated container. The present invention relates to circuits, and particularly to circuits that are simplified and improved in efficiency.

[Prior art] In general, refrigerated containers operate at different voltages (hereinafter 440V).
It can be used with receptacles of two types (explained as two types, 1 and 220), and two types of voltages should not be used at the same time in the same refrigerated container). When operating multiple such refrigerated containers at the same time, each container has 4
A power supply circuit capable of supplying power of 40V and 220V is used. FIG. 3 shows an example of a conventional power supply circuit for refrigerated containers.

First, 11 in the figure is the main switchboard, and this main switchboard 11 has AC440V, 60H2 applied to the 3-phase main bus 12.
The voltage is supplied via the air circuit breaker 13, and its output is applied to the primary side of the first isolation transformer 14. This first three-phase isolation transformer 14 is for 60 Hz with a primary side of 440V and a secondary side of 440V, and its secondary side output is applied to the three-phase bus 16 of the auxiliary power supply board 15. This auxiliary power supply panel 15 is capable of supplying 440V, 60Hz voltage to multiple paths from the three-phase bus 16h1 through the circuit breaker group 17, and one output is supplied to the 440V system box 18.
21 in parallel, and is applied to the primary side of the second three-phase isolation transformer 22. This second three-phase isolation transformer 22 has 6 parts on the primary side 440■ and the secondary side 220■
0H2, and its secondary output is applied to the three-phase bus 24 of the 220V distribution box 23. This distribution box 23 is 3
220V, 60V from the phase bus 24 through the circuit breaker group 25
A voltage of Hz can be divided into three systems, and each output is applied to 22OV system boxes 26 to 28, respectively, and further applied to box 29 via box 28. In addition, the boxes 18, 19 and 26, 27 have four refrigerated container receptacles with circuit breakers, 20° 28
has two refrigerated container receptacles with circuit breakers, 21,
29 incorporates one refrigerated container receptacle with a circuit breaker.

In other words, this power supply circuit is connected to each refrigerated container (not shown).
It is possible to supply both 220V and 440V power to the same refrigerated container.
Since each receptacle of V is not used at the same time, the number of refrigerated containers that can be connected to a total of 22 receptacles built into each box 18-21, 22-29 is 11 (
half of the 22 receptacles). Therefore, the above power supply circuit has 220V and 44V for 11 refrigerated containers.
One 0V receptor is provided for each. [Problems to be Solved by the Invention] By the way, in the conventional power supply circuit for refrigerated containers as described above, the first three-phase isolation transformer 14 is designed to meet the power demand of all refrigerated containers that can be loaded. Because it is selected, it has a very large capacity @
(In the above example, 1080KVA x 2 units for 50 40 foot Xi refrigerated containers) must be used. On the other hand, since the second three-phase isolation transformer 22 is generally provided for every 9 to 15 refrigerated containers, it is necessary to connect and use a large number of small capacity transformers (in the above example, 1 for 40 feet x 10 to 11 units
14 units (50KVA x 1 unit). That is, the first three-phase isolation transformer 14 is used as a 440V system, and the second three-phase isolation transformer 22 is used as a 22OV system, but in this case, the first and second three-phase isolation transformers 14 .22 both have delta connections on the primary and secondary sides. Therefore, in the conventional power supply circuit, if the impedance of each phase on the secondary side of the first isolation transformer 14 and the secondary side of the second isolation transformer 22 do not match, the first and second insulation Transformer 14.22
Since circulating current flows through the 3-phase bus 16 and the circuit breaker group 11 between 440 V and 2
It is necessary to provide an isolation transformer for each of the two 20V systems.

This invention was made to improve the above-mentioned problems, and by using an isolation transformer for multiple systems, it is possible to create a highly efficient refrigerated container with a simple circuit configuration without the risk of heat generation. The purpose is to provide a power supply circuit.

[Means for solving the problem] That is, the power supply circuit for a refrigerated container according to the present invention has the following features:
A plurality of refrigerated containers that can be driven by a first or second three-phase voltage are connected, and power is supplied by transforming the power supply voltage to each refrigerated container receptacle of the first three-phase voltage system and the second three-phase voltage system. in which the primary sides of three single-phase transformers are connected in delta and the secondary sides are connected in star, and a power supply voltage equal to the first three-phase voltage is inputted to the first and second three-phase transformers.
The invention is characterized in that power is supplied to each of the refrigerated container receptacles of the first three-phase voltage system and the second three-phase voltage system using isolation transformers that output three-phase voltages respectively. .

[Function] In other words, the refrigerated container power supply circuit configured as described above can feed different voltages to each receptacle of the refrigerated container using one isolation transformer, so there is no fear of oscillation and the circuit configuration is simple. In addition, efficiency is improved because there is no need to use a large-capacity isolation transformer as in the conventional method.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. However, in FIG. 1, the same parts as in FIG. 3 are denoted by the same reference numerals, and only the different parts will be described here.

FIG. 1 shows the configuration, and the output of the main power supply board 11 is directly applied to the three-phase bus 16 of the auxiliary power supply board 15.

In addition, one three-phase output of the auxiliary switchboard 15 is connected to U, V,
W) is applied through a three-phase power supply line 30 to a three-phase isolation transformer 31 for dual power supply having a dual rated output.

As shown in FIG. 2(a), this double power supply insulating transformer 31 has first to third input terminals UW and first to sixth output terminals u1 to wl.

u2 to W2, and has first and second input terminals (J
, V to the primary winding A1 of the first single-phase transformer A,
The second and third input terminals v, W are connected to the primary winding B1 of the second single-phase transformer B, and the third and first input terminals W,
Connect U to the primary winding C1 of the second single-phase transformer C, connect one end of each of the secondary windings A2 to C2 of each single-phase transformer A-C in common, and output the other end, respectively. It is connected to terminals u1 to W1, and the intermediate taps are connected to output terminals u2 to W2, respectively. In other words, the first to third single-phase transformers A to C
Each primary side is connected in a delta connection, and each secondary side is connected in a star connection, and the input terminals Ll-W are connected to each phase U to W of the three-phase power supply line 31, and the output terminals u1 to W1 are connected to each other.
is connected to each box 18 of the 440V system through the 3-phase feeder line 32.
~21, and the output terminals u2~W2 are connected to the three-phase feeder line 3.
3 to the three-phase bus 24 of the 220V power divider 23. The turns ratio of the first to third single-phase transformers A-C is 1:1 at both ends of the secondary windings A2-C2, and 2:1 at the intermediate tap position.

Here, the operation of the three-phase isolation transformer 31 for dual power feeding will be explained with reference to FIG. 2(b).

Fig. 2(b) shows the first single-phase transformer A taken out, and an AC power supply E is connected between the input terminal U and When applied, the voltage E1 appearing at the output terminal u-v2111 is AC220V, 60H2 because the winding ratio is 2:1,
The voltage E2 appearing between the output terminals u and vI has a turns ratio of 1:1.
Therefore, AC440V, 601h (-EO). The same applies to the second and third single-phase transformers B and C, so that the output terminals u1 to w1 of the three-phase insulating transformer 31 for double power supply are equivalent to the output of the auxiliary switchboard 15. (7) A three-phase voltage of 440 VAC and 60 Hz appears, and a three-phase voltage of 220 VAC and 60 Hz, which is half of the output of the auxiliary arrangement fl115, appears at the output terminals u2 to w2.

That is, in the refrigerated container power supply circuit, the insulation transformer 31 having the dual rated output is used to
It also has the functions of the second isolation transformer 14.22. For this reason, the transformer 31 is connected to each box 18 to 21.26.
It is set to have power supply capacity capable of supplying power to 11 refrigerated containers connected to 22 receptacles of ~29. And each box 18-2 of 440V system
9 is supplied with power in parallel from the isolation transformer 31 through the three-phase power supply line 32, and the output of the isolation transformer 31 is applied to the boxes 26 to 29 of the 22OV system through the three-phase power supply line 33 to the power divider 24 at one end. After that, power is supplied in series by this power divider 24 (however, 28 and 29 are connected in parallel). Such a connection is determined depending on the power supply capacity so that the overall cost is the lowest.

Now, if we consider the capacity of the single-phase transformer A shown in Fig. 2(b), the equivalent capacity KV,l on the secondary side is KVA1 KVA2 + KVA2 /2 (A) (However, KVA2 is the electric power [KVAko] determined by the maximum input required by the refrigerated container, and the equivalent capacity KVA3 of two windings is KVA3- (
KVA2 +KVA1 )/2...(b). That is, the primary side 440 with delta and star connections.
V, secondary (150KVA at 1440V.

220Vt'150KVA, RL large 150KVA
(440V, 220■ mixed use), if it is possible to use up to 2
The equivalent capacity on the next side is 50+25-75KVA because Vl-v2 is 220V and 25KVA.

Therefore, the equivalent capacity of the two windings is (50+75>/2-62.5KVA,!).This is also true for the other single-phase transformers 8.0.

Therefore, the three-phase isolation transformer 31 is replaced by the single-phase transformer A-
Since the primary side of C is delta connected and the secondary side is star connected to form 3 phases, its rated output is 440V and 2
20 ■, respectively 150KVA, and the overall rating is 62.5KVAx3-187.5KVA.

Next, let's consider the capacity of the entire power supply circuit.

In the conventional power supply circuit shown in Fig. 3, as mentioned above,
The first isolation transformer 14 is one 1080KVAX unit - (44
0V/440V) r, the second isolation transformer 22 is 15
If it is 0KVA x 14 units (440V/220V), the total will be 4260KVA, but since the power supply circuit according to this invention shown in Fig. 1 will only require 187.5KVA x 14 units (440V/440V/220V), the total will be 2625KVA. becomes. Comparing the costs, a normal transformer with a capacity of 1080KVA17) costs 2.7 million yen, and a transformer with a capacity of 15
If a 0KVA transformer can be manufactured for 448,000 yen and a 187.5KVA transformer shown in Figure 2 (a) can be manufactured for 550,000 yen, the conventional power supply circuit will cost 270x2+44
．． 8x14 = 11,672,000 yen, whereas the power supply circuit according to the present invention costs 55.0x14 = 7,700,000 yen, making the difference 3,972,000 yen cheaper.

Therefore, the refrigerated container power supply circuit configured as described above can feed different voltages to each receptacle of the refrigerated container using one isolation transformer, so there is no fear of oscillation and the circuit configuration is simple. Furthermore, efficiency is improved because there is no need to use a large-capacity isolation transformer as in the conventional method.

Incidentally, when the 22OV system refrigerated container is 40 feet long, the insulating transformer 31 of the above embodiment is divided into a set of 4 at most, and a set of 20
If the 440V system is 40 feet, connect up to 8 units as a set to the circuit breaker 25 of the distribution device 23, and if the 440V system is 40 feet, then up to 15 units, and if the 440V system is 20 feet, connect up to 30 units.
A set of units can be connected to the secondary side of the isolation transformer 31. Further, the present invention is not limited to the above-mentioned embodiments, and can be implemented in the same manner even in cases where the rated outputs are of the other two types.

[Effect of the invention] As detailed above, according to the present invention, the first or second
A plurality of refrigerated containers that can be driven with a three-phase voltage of The primary sides of each of the three phase transformers are connected in delta, and the secondary sides are connected in star, and a power supply voltage equal to the first three-phase voltage is input to obtain the first and second three-phase voltages. By supplying power to each refrigerated container receptacle of the first three-phase voltage system and the second three-phase voltage system using isolation transformers that output respectively, it is possible to use isolation transformers for multiple systems. Since it is used for both purposes, it is possible to provide a power supply circuit for a refrigerated container that is free from heat generation, has a simple circuit configuration, and is highly efficient.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram showing one embodiment of a power supply circuit for a refrigerated container according to the present invention, and FIG. 2(a). (b) is a circuit diagram for explaining the configuration and operation of the three-phase isolation transformer for dual power supply used in the same embodiment, and FIG. 3 is a circuit diagram showing the configuration of a conventional power supply circuit for refrigerated containers. be. 11... Main switchboard, 12... 3-phase main bus, 13...
- Air circuit breaker, 14... first isolation transformer 15...
Auxiliary power supply board, 16... 3-phase bus, 17... Breaker group, 18-21... 440V system box 18-21.2
2... Second 3-phase isolation transformer, 23... 220 ■ Distribution box, 24... 3-phase bus bar, 25... Breaker group, 26
~29...220V box, 30.32.33.
...3-phase power supply line, 31... is a 3-phase isolation transformer for double power feeding.

Claims (1)

[Claims] A plurality of refrigerated containers that can be driven by a first or second three-phase voltage are connected, and power is supplied by transforming the power supply voltage to each refrigerated container receptacle of the first three-phase voltage system and the second three-phase voltage system. In a power supply circuit for a refrigerated container, the primary sides of three single-phase transformers are connected in delta, and the secondary sides are connected in star, and a power supply voltage equal to the first three-phase voltage is input to Power is supplied to each refrigerated container receptable of the first three-phase voltage system and the second three-phase voltage system using isolation transformers that output the first and second three-phase voltages, respectively. Power supply circuit for refrigerated containers.