KR20100011876A - Transforming apparatus for automatically adjusting three-phase power supply voltage - Google Patents

Abstract

A transformation device has three input terminals, three output terminals, a Y-connected three-phase transformer, a group of switches, and a switch switching circuit, and automatically adjusts the voltage of a three-phase power supply. The three input terminals are connected respectively with the three trunk lines of the three-phase power supply, and the three output terminals are connected respectively with load equipment. The Y-connected three-phase transformer has a core, an R-phase winding circuit, an S-phase winding circuit, and a T-phase winding circuit. The R-phase winding circuit has an R-phase main winding, an R-phase first sub-winding, an R-phase first switch, an R-phase second sub-winding, and an R-phase third sub- winding connected in series in this order between an input terminal Rin and a neutral point, and has an output terminal Rout at the other end of the R-phase main winding. An R-phase second switch is connected in parallel to a series circuit composed of the R-phase first sub-winding and the R-phase first switch. An R-phase third switch is connected in parallel to a series circuit composed of the R-phase first sub-winding, the R-phase first switch, and the R-phase second sub-winding. An R-phase fourth switch is connected in parallel to a series circuit composed of the R-phase second sub-winding and the R-phase third sub-winding. The switch switching circuit controls the group of the switches according to the voltage levels of the output terminals to alternatively switch first to fourth modes.

Description

Transformer for automatically adjusting three-phase power voltage {TRANSFORMING APPARATUS FOR AUTOMATICALLY ADJUSTING THREE-PHASE POWER SUPPLY VOLTAGE}

The present invention relates to a transformer device that automatically adjusts the voltage of a three-phase power source introduced into a power consumer position within a target voltage range lower than its rated voltage and supplies the load equipment. Specifically, a Y-connected three-phase transformer is provided. It relates to such a transformer device having a basic configuration.

For example, in hotels, supermarkets, factories, etc., lighting equipment, air conditioning equipment, power devices, and the like consume large amounts of power. Recently, these general power consumers have been strongly aware of the need for energy saving means, and various means have been proposed and realized.

One of the energy saving measures that can be adopted by the general power consumer is disclosed in Japanese Patent No. 2750275 or 3372178, which automatically adjusts the voltage of a commercial power supply to a voltage several percent lower than its rated voltage and supplies the load equipment. Known transformers are known installations in faucet systems that draw commercial power into indoor equipment.

In areas where the stability of power generation and distribution facilities is inferior, the power supply voltage at the power consumer's power receiving point is not stable and often fluctuates in the voltage range slightly above the rated voltage. In this situation, the power supply is automatically adjusted to a voltage that is several percent lower than the rated voltage to the load equipment, thereby greatly reducing the power consumption of the load device, which is particularly effective in terms of energy saving.

[Problem to Solve Invention]

The transformer disclosed in Japanese Patent No. 3372178 described above automatically adjusts the voltage of the three-phase power supply within a target voltage range lower than the rated voltage and supplies it to the load equipment. However, the winding configuration of the transformer used in this transformer is not a Y connection, but a special configuration in which the current and magnetic flux of each phase are combined with the current and magnetic flux of the other phase, so that the winding circuit and It is very difficult to design a magnetic circuit.

Since the above-described conventional transformer device is configured to change its transformer characteristic by switching on / off by combining a plurality of switches connecting different phases, the switch has a voltage across the switch (voltage between different phases). It should be switched on / off at this zero timing. Therefore, the switch control circuit is complicated, and therefore, it is difficult to ensure the stability and reliability of the switching operation timing.

An object of the present invention is to provide a transformer device having a Y-connected three-phase transformer as a basic configuration by automatically adjusting the voltage of a three-phase power supply within a target voltage range lower than the rated voltage and supplying it to the load equipment.

[Means for solving the problem]

The transformer device according to the present invention is characterized by having the following items (1) to (22).

(1) Transformers that automatically adjust the voltage of a three-phase power supply include three input terminals (Rin, Sin, Tin), three output terminals (Rout, Sout, Tout), a Y-connected three-phase transformer, a switch group, and A switch switching circuit.

(2) The three input terminals Rin, Sin, and Tin are connected to three main lines of the three-phase power source, respectively.

(3) The three output terminals Rout, Sout and Tout are connected to a load installation.

(4) The Y-connected three-phase transformer includes a core, an R-phase winding circuit, an S-phase winding circuit, and a T-phase winding circuit.

(5) In the R-phase winding circuit, the R-phase main winding, the R-phase first auxiliary winding, the R-phase first switch, the R-phase second auxiliary winding, and the R-phase third auxiliary winding are the input terminals Rin in this order. ) Is connected in series between the neutral point (O), and the output terminal (Rout) is connected to the other end of the R-phase main winding.

(6) The R phase second switch of the switch group is connected in parallel to the series circuit of the R phase first auxiliary winding and the R phase first switch.

(7) The R phase third switch of the switch group is connected in parallel to the series circuit of the R phase first auxiliary winding, the R phase first switch, and the R phase second auxiliary winding.

(8) The R phase fourth switch of the switch group is connected in parallel to the series circuit of the R phase second auxiliary winding and the R phase third auxiliary winding.

(9) In the S-phase winding circuit, the S-phase main winding, the S-phase first auxiliary winding, the S-phase first switch, the S-phase second auxiliary winding, and the S-phase third auxiliary winding are the input terminals Sin in this order. ) And a neutral point (O) are connected in series, and the output terminal (Sout) is connected to the other end of the S-phase main winding.

(10) The S phase second switch of the switch group is connected in parallel to the series circuit of the S phase first auxiliary winding and the S phase first switch.

(11) The S-phase third switch of the switch group is connected in parallel to the series circuit of the S-phase first auxiliary winding, the S-phase first switch, and the S-phase second auxiliary winding.

(12) The S-phase fourth switch of the switch group is connected in parallel to the series circuit of the S-phase second auxiliary winding and the S-phase third auxiliary winding.

(13) In the T-phase winding circuit, the T-phase main winding, the T-phase first auxiliary winding, the T-phase first switch, the T-phase second auxiliary winding, and the T-phase third auxiliary winding are sequentially connected to the input terminal (Tin). ) Is connected in series between the neutral point O, and the output terminal Tout is connected to the other end of the T-phase main winding.

(14) The T phase second switch of the switch group is connected in parallel to the series circuit of the T phase first auxiliary winding and the T phase first switch.

(15) The T-phase third switch of the switch group is connected in parallel to the series circuit of the T-phase first auxiliary winding, the T-phase first switch, and the T-phase second auxiliary winding.

(16) The T phase fourth switch of the switch group is connected in parallel to the series circuit of the T phase second auxiliary winding and the T phase third auxiliary winding.

(17) The switch switching circuit controls the switches based on the voltage level of the output terminals (Rout, Sout, Tout) or input terminals (Rin, Sin, Tin) to selectively switch among the first to fourth modes. .

(18) In the first mode, the first switch of each phase is turned on, and the second, third, and fourth switches of each phase are turned off.

(19) In the second mode, the second switch of each phase is turned on, and the first, third, and fourth switches of each phase are turned off.

(20) In the third mode, the third switch of each phase is turned on, and the first, second, and fourth switches of each phase are turned off.

(21) In the fourth mode, the fourth switch of each phase is turned on, and the first, second, and third switches of each phase are turned off.

(22) The switch switching circuit causes the switches of each phase to be switched on / off at a timing at which the voltage instantaneous value of each phase becomes zero, thereby switching the mode.

1 is a configuration diagram of a winding of a transformer according to an exemplary embodiment of the present invention.

2 is a block diagram of a core according to an embodiment of the present invention.

3 is a configuration diagram of a switch switching circuit according to an embodiment of the present invention.

4 is a flowchart of a process procedure by the microcomputer 82 in an embodiment of the present invention.

FIG. 5 is a diagram showing an example of the configuration of one switch and its corresponding portion in the switch switching circuit; FIG.

[Description of Drawing Reference]

Rin, Sin, Tin: Input Terminals Rout, Sout, Tout: Output Terminals

10R: R phase main winding 10S: S phase main winding 10T: T phase main winding

11R: R phase first auxiliary winding 11S: S phase first auxiliary winding 11T: T phase first auxiliary winding

12R: R phase secondary auxiliary winding 12S: S phase secondary auxiliary winding 12T: T phase secondary auxiliary winding

13R: R phase third auxiliary winding 13S: S phase third auxiliary winding 13T: T phase third auxiliary winding

21R: R phase first winding 21S: S phase first winding 21T: T phase first winding

22R: R phase second winding 22S: S phase second winding 22T: T phase second winding

23R: Third phase winding of R phase 23S: Third phase winding of S phase 23T: Third phase winding of T phase

24R: R-phase fourth winding 24S: S-phase fourth winding 23T: T-phase fourth winding

5: core

5R: R-phase winding 5S: S-phase winding 5T: T-phase winding

8: switch switching circuit 81: voltage detection circuit

82: microcomputer 83: drive circuit

51, 52: thyristor 53: gate signal generation circuit

54, 55: voltage detection circuit

=== Summary of Transformers ===

1 shows the winding configuration of the transformer device according to the invention, and FIG. 3 shows the configuration of the switch switching circuit 8. First, a general outline of this transformer is described.

The transformer includes three input terminals (Rin, Sin, Tin) connected to three main lines of a three-phase power supply, and three output terminals (Rout, Sout, Tout) connected to a load installation. It includes. The transformer device includes a first mode that lowers the output voltage by about 2% below the input voltage, a second mode that lowers the output voltage about 4% below the input voltage, a third mode lowers the output voltage about 6% below the input voltage, and The output voltage is selectively switched among the fourth modes to make the output voltage substantially equal to the input voltage.

The transformer device includes, as a basic configuration, a Y-connected three-phase transformer composed of an R-phase winding circuit, an S-phase winding circuit, and a T-phase winding circuit having the same configuration as shown in FIG.

=== R phase winding circuit ===

In the R phase winding circuit, the R phase main winding 10R, the R phase first auxiliary winding 11R, the R phase first switch 21R, the R phase second auxiliary winding 12R, and the R phase third auxiliary winding (13R) is connected in series between the input terminal (Rin) and the neutral point (O) in this order. The output terminal Rout is connected to the other end of the R-phase main winding 10R.

The R-phase second switch 22R is connected in parallel to the series circuit of the R-phase first auxiliary winding 11R and the R-phase first switch 21R.

The R phase third switch 23R is connected in parallel to the series circuit of the R phase first auxiliary winding 11R, the R phase first switch 21R and the R phase second auxiliary winding 12R.

The R phase fourth switch 24R is connected in parallel to the series circuit of the R phase second auxiliary winding 12R and the R phase third auxiliary winding 13R.

=== S phase winding circuit ===

In the S-phase winding circuit, the S-phase main winding 10S, the S-phase first auxiliary winding 11S, the S-phase first switch 21S, the S-phase second auxiliary winding 12S, and the S-phase third auxiliary winding 13S is connected in series between the input terminal Sin and the neutral point O in this order. The output terminal Sout is connected to the other end of the S-phase main winding 10S.

The S-phase second switch 22S is connected in parallel to the series circuit of the S-phase first auxiliary winding 11S and the S-phase first switch 21S.

The S-phase third switch 23S is connected in parallel to the series circuit of the S-phase first auxiliary winding 11S, the S-phase first switch 21S and the S-phase second auxiliary winding 12S.

The S-phase fourth switch 24S is connected in parallel to the series circuit of the S-phase second auxiliary winding 12S and the S-phase third auxiliary winding 13S.

=== T phase winding circuit ===

In the T-phase winding circuit, the T-phase main winding 10T, the T-phase first auxiliary winding 11T, the T-phase first switch 21T, the T-phase second auxiliary winding 12T, and the T-phase third auxiliary winding 13T is connected in series between the input terminal Tin and the neutral point O in this order. The output terminal Tout is connected to the other end of the T-phase main winding 10T.

The T-phase second switch 22T is connected in parallel to the series circuit of the T-phase first auxiliary winding 11T and the T-phase first switch 21T.

The T-phase third switch 23T is connected in parallel to the series circuit of the T-phase first auxiliary winding 11T, the T-phase first switch 21T and the T-phase second auxiliary winding 12T.

The T-phase fourth switch 24T is connected in parallel to the series circuit of the T-phase second auxiliary winding 12T and the T-phase third auxiliary winding 13T.

=== Example of Core 5 ===

Fig. 2 shows an example of the form of the core 5 of the Y-connected three-phase transformer. The windings 10R, 11R, 12R, 13R of the R-phase winding circuit are wound around the R-phase winding 5R of the core 5. The windings 10S, 11S, 12S, 13S of the S-phase winding circuit are wound around the S-phase winding 5S of the core 5. The windings 10T, 11T, 12T, 13T of the T-phase winding circuit are wound around the T-phase winding 5T of the core 5.

=== Summary of the switch switching circuit 8 ===

3 shows an example of the configuration of the switch switching circuit 8. The switch switching circuit 8 monitors the voltage levels of the output terminals Rout, Sout, and Tout to selectively switch among the first to fourth modes so that the output voltage is within a predetermined target voltage range. It is configured to control the group.

In the first mode, the first switches 21R, 21S, 21T of each phase are turned on, and the other switches (second, third, and fourth switches of each phase) are turned off. In the first mode, the output voltage is about 2% lower than the input voltage.

In the second mode, the second switches 22R, 22S, 22T of each phase are turned on, and the other switches (first, third, and fourth switches of each phase) are turned off. In the second mode, the output voltage is about 4% lower than the input voltage.

In the third mode, the third switches 23R, 23S, 23T of each phase are turned on, and the other switches (first, second, and fourth switches of each phase) are turned off. In the third mode, the output voltage is about 6% lower than the input voltage.

In the fourth mode, the fourth switches 24R, 24S, 24T of each phase are turned on, and the other switches (first, second, third switches of each phase) are turned off. In the fourth mode, the output voltage is substantially equal to the input voltage.

=== Details of the switch switching circuit 8 ===

As shown in FIG. 3, the switch switching circuit 8 includes a voltage detection circuit 81, a microcomputer 82, and a drive circuit 83. The voltage detection circuit 81 detects the voltage level of the output terminals Rout, Sout, and Tout and inputs a detection signal to the microcomputer 82. The microcomputer 82 performs the process shown in the flowchart of FIG. 4 based on the detection signal from the voltage detection circuit 81 and inputs a control signal to the driving circuit 83 to selectively select among the first to fourth modes. Let the switch In accordance with the control signal from the microcomputer 82, the drive circuit 83 includes the first to fourth switches 21R to 24R in R, the first to fourth switches 21S to 24S in S, and the first on T. The 1st to 4th switches 21T to 24T are turned on and off.

An example of the process procedure of the microcomputer 82 will be described with reference to the flowchart of FIG. 4. The microcomputer 82 compares the detection signal from the voltage detection circuit 81 with a predetermined target voltage range and monitors whether the output voltage is higher or lower than the target voltage range (steps 410 and 420).

If the output voltage is above the target voltage range, the process proceeds to the step-down routine after step 411. In the step-down routine, the transformer switches to the first mode (-2% mode) if it is currently the fourth mode (0% mode) and the second mode (-4% mode) if it is currently the first mode (-2% mode). If the current mode is the second mode (-4% mode), it is switched to the third mode (-6% mode).

If the output voltage is below the target voltage range, the process proceeds to a boost routine after step 421. In the boost routine, the transformer switches to the second mode (-4% mode) if it is currently in the third mode (-6% mode) and the first mode (-2% if it is currently in the second mode (-4% mode). Mode), and if the current mode (-2% mode), the fourth mode (0% mode).

=== Specific example of drive circuit 83 and switch ===

As described above, twelve switches are included in the circuit of the Y-connected three-phase transformer shown in FIG. 1, and these switches are individually switched on and off by the driving circuit 83 shown in FIG. 3. The twelve switches and their respective circuits in the drive circuit 83 are identical in configuration to each other.

FIG. 5 shows an example of the configuration of one of twelve switches and one corresponding circuit in the drive circuit 83. The switch is composed of two thyristors 51 and 52 connected in opposite directions to each other. The driving circuit 83 includes a gate signal generation circuit 53 and two voltage detection circuits 54 and 55. The gate signal generation circuit 53 outputs the gate signal G1 to turn on the thyristor 51, and outputs the gate signal G2 to turn on the thyristor 52.

The voltage detection circuit 54 detects the gate-cathode voltage of the thyristor 51, and the output signal A of the voltage detection circuit becomes the current when the gate-cathode voltage becomes zero (the current passing through the thyristor 51 becomes Becomes zero, and if the gate-cathode voltage is not zero when the current passes through the thyristor 51, its output signal A is " 0 ".

Similarly, the voltage detection circuit 55 detects the gate-cathode voltage of the thyristor 52, and the output signal B of the voltage detection circuit passes when the gate-cathode voltage becomes zero (which passes through the thyristor 52). When the current goes to zero, " 1 ", and if the gate-cathode voltage is not zero when the current passes through the thyristor 52, the output signal B is " 0 ".

The microcomputer 82 of FIG. 3 provides a control signal for instructing the turn-off of the thyristors 51 and 52 (one of the switches) to the driving circuit 83 (including the gate signal generating circuit 53) of FIG. In this case, the gate signal generation circuit 53 supplies the thyristors 51 and 52 to the output signals A and B of the voltage detection circuits 54 and 55 through " 1 " Turn off. In addition, instead of the turned off thyristors 51 and 52 (one switch), another switch is turned on (of two thyristors connected in parallel in opposite directions) to be turned on.

Thus, the switch switching circuit 8 of FIG. 3 is configured to switch the modes on and off by switching the switches on and off at the timing when the voltage instantaneous value of each phase becomes zero. In this embodiment, each switch is composed of thyristors connected in parallel in opposite directions to each other, and the switch switching circuit 8 includes a voltage detector for detecting the gate-cathode voltage of each thyristor, and turns off one thyristors. And turn on another thyristor at a timing at which it is detected that its gate-cathode voltage has just gone to zero through the thyristor's voltage detector being turned off.

Claims (2)

In a transformer for automatically adjusting the voltage of a three-phase power supply, Three input terminals (Rin, Sin, Tin), Three output terminals (Rout, Sout, Tout), With Y connection three phase transformer, With switch groups, Switch switching circuit Including; The three input terminals (Rin, Sin, Tin) are each connected to three main lines of the three-phase power source, The three output terminals (Rout, Sout, Tout) are connected to a load installation, The Y-connected three-phase transformer includes a core, an R phase winding circuit, an S phase winding circuit, and a T phase winding circuit. In the R-phase winding circuit, the R-phase main winding, the R-phase first auxiliary winding, the R-phase first switch, the R-phase second auxiliary winding, and the R-phase third auxiliary winding in this order are the input terminal Rin and a neutral point. (O) is connected in series, the output terminal (Rout) is connected to the other end of the R-phase main winding, The R phase second switch of the switch group is connected in parallel to the series circuit of the R phase first auxiliary winding and the R phase first switch, The R phase third switch of the switch group is connected in parallel to the series circuit of the R phase first auxiliary winding, the R phase first switch, and the R phase second auxiliary winding, An R-phase fourth switch of the switch group is connected in parallel to a series circuit of the R-phase second auxiliary winding and the R-phase third auxiliary winding; In the S-phase winding circuit, the S-phase main winding, the S-phase first auxiliary winding, the S-phase first switch, the S-phase second auxiliary winding, and the S-phase third auxiliary winding in this order are the input terminal Sin and a neutral point. (O) is connected in series, the output terminal (Sout) is connected to the other end of the S-phase main winding, The S phase second switch of the switch group is connected in parallel to the series circuit of the S phase first auxiliary winding and the S phase first switch, The S phase third switch of the switch group is connected in parallel to the series circuit of the S phase first auxiliary winding, the S phase first switch, and the S phase second auxiliary winding, The S-phase fourth switch of the switch group is connected in parallel to the series circuit of the S-phase second auxiliary winding and the S-phase third auxiliary winding, In the T-phase winding circuit, the T-phase main winding, the T-phase first auxiliary winding, the T-phase first switch, the T-phase second auxiliary winding, and the T-phase third auxiliary winding in this order are the input terminal Tin and the neutral point. (O) is connected in series, the output terminal (Tout) is connected to the other end of the T-phase main winding, The T-phase second switch of the switch group is connected in parallel to the series circuit of the T-phase first auxiliary winding and the T-phase first switch, A third phase T switch of the switch group is connected in parallel to a series circuit of the first phase T auxiliary winding, the first phase T switch, and the second phase T auxiliary winding; The T-phase fourth switch of the switch group is connected in parallel to the series circuit of the T-phase second auxiliary winding and the T-phase third auxiliary winding, The switch switching circuit controls the switches based on the voltage level of the output terminals (Rout, Sout, Tout) or input terminals (Rin, Sin, Tin) to selectively switch among the first to fourth modes, In the first mode, the first switch of each phase is turned on, and the second, third, and fourth switches of each phase are turned off,  In the second mode, the second switch of each phase is turned on, and the first, third, and fourth switches of each phase are turned off, In the third mode, the third switch of each phase is turned on, and the first, second, and fourth switches of each phase are turned off, In the fourth mode, the fourth switch of each phase is turned on, and the first, second, and third switches of each phase are turned off, Wherein the switch switching circuit switches the switches of each phase on / off at a timing at which the voltage instantaneous value of each phase becomes zero so as to switch modes. 2. The apparatus of claim 1, wherein each of the switches comprises thyristors connected in parallel in opposite directions to each other, the switch switching circuit including a voltage detector to detect a gate-cathode voltage of each of the thyristors, Turning off one thyristo, and turning on another thyristor in response to a timing at which it is detected that its gate-cathode voltage has just gone through the voltage detector of the thyristor being turned off.

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