MD1786Z - Transformer device for asymmetrical load connection to a three-phase power supply - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used for connecting groups of household consumers of electric power to a symmetrical three-phase power supply.The transformer device for asymmetrical load connection to a three-phase power supply comprises a transformer with primary (4, 5, 6) and secondary (7, 8, 9) windings, placed in pairs on the rods (1, 2, 3) of the transformer core, according to phases A, B, C, and nine identical control winding blocks (10, 11, 12, 13, 14, 15, 16, 17, 18), placed in threes on each rod (1, 2, 3) of the transformer core. The secondary winding (7) of phase A and the control winding blocks (10), (14), (17) are connected in series, at the same time this circuit is the output of phase A, the secondary winding (8) of phase B and the control winding blocks (13), (11), (18) are connected in series, at the same time this circuit is the output of phase B, and the secondary winding (9) of phase C and the control winding blocks (16), (15), (12) are connected in series, at the same time this circuit is the output of phase C. Each control winding block (10, 11, 12, 13, 14, 15, 16, 17, 18) contains three winding sections with a turn ratio of 1:3:9, and eighteen identical electronic keys, at the same time to the control inputs of each key via a corresponding switch is connected a control unit.

Description

The invention relates to the field of electrical engineering and can be used to connect groups of household electricity consumers to a symmetrical three-phase power supply.

For example, a city is supplied with electricity from a power plant through a high-voltage power line. After the necessary voltage reduction, the power lines go from the city to the villages surrounding this city. The villages develop and the electricity consumption in them changes, i.e., over time the load becomes asymmetric (unbalanced) and must be coordinated with a symmetrical three-phase power supply.

A two-transformer device for phase shift adjustment is known, which contains two transformers with windings, including adjustment windings [1].

The disadvantage of this device is its complexity and, as a consequence, its low reliability. This disadvantage is due to the fact that the device contains two transformers.

A transformer device for phase shift adjustment is also known, which comprises a transformer with primary and secondary windings, including adjustment windings - one in each phase [2].

The disadvantage of this device is the limited possibilities of adjusting the phase shift. This disadvantage is due to the fact that the device contains a single regulating winding in each phase, which does not allow obtaining the necessary variety of voltages and phase shifts.

The problem that the invention solves consists in creating a device that allows the expansion of the regulation capacity before connecting the asymmetrical load to the symmetrical three-phase power supply.

The transformer device for connecting an asymmetrical load to a three-phase power supply, according to the invention, eliminates the above-mentioned disadvantages by containing a transformer with primary and secondary windings, located in pairs on the rods of the transformer core, corresponding to phases A, B, C, as well as nine identical blocks of regulating windings, at the same time the windings of the first, second and third blocks of regulating windings are located on the rod of phase A of the transformer core, the windings of the fourth, fifth and sixth blocks of regulating windings - on the rod of phase B of the transformer core and the windings of the seventh, eighth and ninth blocks of regulating windings - on the rod of phase C of the transformer core. The secondary winding of phase A, as well as the first, fifth and eighth blocks of regulating windings are connected in series, this circuit representing the output of phase A; the secondary winding of phase B, as well as the fourth, second and ninth blocks of regulating windings are connected in series, this circuit representing the output of phase B; the secondary winding of phase C, as well as the seventh, sixth and third blocks of regulating windings are connected in series, this circuit representing the output of phase C; at the same time, the outputs of these phases are intended for connection to the consumer. Each block of control windings contains three winding sections: the first, the second and the third with the ratio of the number of turns 1:3:9, as well as eighteen identical electronic keys, to the control inputs of each key being connected through a corresponding switch one control block. The beginning of the first winding section is connected through the first key to the first output of the block of control windings, and the end of the third winding section is connected through the sixteenth key to the second output of the block of control windings; the beginning of the first winding section through the fourth key and its end through the fifth key are connected to the end of the third winding section; the beginning of the second winding section through the sixth key and its end through the seventh key are connected to the end of the third winding section; the beginning of the third winding section through the eighth key is connected to the end of the second winding section and through the ninth key - to the beginning of the second winding section; the beginning of the third winding section through the tenth key is connected to the end of the first winding section, and through the eleventh key - to the beginning of the first winding section; the end of the second winding section through the twelfth key is connected to the end of the first winding section and through the thirteenth key is connected to its beginning; the beginning of the second winding section through the fourteenth key is connected to the end of the first winding section, and through the fifteenth key is connected to its beginning; the end of the first winding section through the second key and the end of the second winding section through the third key are connected to the first output of the regulating winding block, and the beginning of the second winding section through the seventeenth key and the beginning of the third winding section through the eighteenth key are connected to the second output of the regulating winding block.

The advantages of the invention consist in the fact that this assembly of elements provides an extension of the regulation capabilities, since the regulation can be carried out separately for each phase, both by amplitude (the first, fourth and seventh blocks of regulation windings), as well as by phase (a combination of the voltages of two blocks of regulation windings with the voltage vectors located at angles of 120° and 240° relative to the voltage vector of the phase regulated by these blocks, since their windings are located on the rods of other phases of the transformer core), thereby achieving the possibility of adjustment to an asymmetric load to ensure connection to a three-phase symmetrical energy source, i.e. the problem of the invention is solved.

The invention is explained by the drawings in Fig. 1 and 2, which represent:

- Fig. 1, diagram of the claimed device showing the location of the primary and secondary windings and the regulating winding blocks on the transformer core rods;

- Fig. 2, block diagram of the regulating windings of the claimed device.

List of reference signs in Fig. 1:

1 - phase A rod of the transformer core; 2 - phase B rod of the transformer core; 3 - phase C rod of the transformer core; 4 - primary winding of phase A; 5 - primary winding of phase В; 6 - primary winding of phase С; 7 - secondary winding of phase А; 8 - secondary winding of phase В; 9 - secondary winding of phase С; 10 - first block of regulating windings; 11 - second block of regulating windings; 12 - third block of regulating windings; 13 - fourth block of regulating windings; 14 - fifth block of regulating windings; 15 - sixth block of regulating windings; 16 - seventh block of regulating windings; 17 - the eighth block of regulating windings; 18 - the ninth block of regulating windings. The input pairs of the claimed device are marked with the letters: A1 (phase A); B1 (phase B); C1 (phase C). The outputs of the claimed device are marked with the letters: A2 and A2 (phase A); B2 and B2 (phase B); C2 and C2 (phase C).

List of reference signs in Fig. 2:

19 - a part of the transformer core rod of the phase, on which the winding sections of the regulating winding block are located; 20 - the first section of the regulating winding, 21 - the second section of the regulating winding; 22 - the third section of the regulating winding; 23 - the first electronic key; 24 - the second electronic key; 25 - the third electronic key; 26 - the fourth electronic key; 27 - the fifth electronic key; 28 - the sixth electronic key; 29 - the seventh electronic key; 30 - the eighth electronic key; 31 - the ninth electronic key; 32 - the tenth electronic key; 33 - the eleventh electronic key; 34 - the twelfth electronic key; 35 - the thirteenth electronic key; 36 - the fourteenth electronic key; 37 - the fifteenth electronic key; 38 - the sixteenth electronic key; 39 - the seventeenth electronic key; 40 - the eighteenth electronic key; 41 - the first switch; 42 - the second switch; 43 - the third switch; 44 - the fourth switch; 45 - the fifth switch; 46 - the sixth switch; 47 - the seventh switch; 48 - the eighth switch; 49 - the ninth switch; 50 - the tenth switch; 51 - the eleventh switch; 52 - the twelfth switch; 53 - the thirteenth switch; 54 - the fourteenth switch; 55 - the fifteenth switch; 56 - the sixteenth switch; 57 - the seventeenth switch; 58 - the eighteenth switch; 59 - the first control block; 60 - the second control block; 61 - the third control block; 62 - the fourth control block; 63 - the fifth control block; 64 - the sixth control block; 65 - the seventh control block; 66 - the eighth control block; 67 - the ninth control block; 68 - the tenth control block; 69 - eleventh control block; 70 - twelfth control block; 71 - thirteenth control block; 72 - fourteenth control block; 73 - fifteenth control block; 74 - sixteenth control block; 75 - seventeenth control block; 76 - eighteenth control block; 77 - electrical harness.

Bus D - the first and second outputs of the control winding block.

The device shown in Fig. 1 consists of the following nodes and links:

On the rod 1 of phase A of the transformer core are located: the primary winding 4 of phase A, the secondary winding 7 of phase A, as well as the windings of the first 10, the second 11 and the third 12 blocks of regulating windings. On the rod 2 of phase B of the transformer core are located: the primary winding 5 of phase B, the secondary winding 8 of phase B, as well as the windings of the fourth 13, the fifth 14 and the sixth 15 blocks of regulating windings. On the rod 3 of the phase C of the transformer core are located: the primary winding 6 of the phase C, the secondary winding 9 of the phase C, as well as the windings of the seventh 16, the eighth 17 and the ninth 18 blocks of regulating windings. The secondary winding 7 of the phase A, as well as the first 10, the fifth 14 and the eighth 17 blocks of regulating windings are connected in series and this circuit represents the output of the phase A; the secondary winding 8 of the phase B, as well as the fourth 13, the second 11 and the ninth 18 blocks of regulating windings are connected in series and this circuit represents the output of the phase B; the secondary winding 9 of phase C, as well as the seventh 16, the sixth 15 and the third 12 blocks of regulating windings are connected in series and this circuit represents the output of phase C. The outputs of these phases A, B, C are connected to the consumer.

The device shown in Fig. 2 (the regulating winding block) consists of the following nodes and connections:

On that rod 19 of the transformer core, on which the windings of this block of regulating windings are located, there are the first 20, the second 21 and the third 22 sections of these windings with the ratio of the number of turns 1:3:9. This block also includes eighteen (from the first to the eighteenth) identical electronic keys, the reference signs of which are, respectively, from 23 to 40. They are made as bidirectional in order to have the possibility of working on alternating current. To the control inputs of each of these keys through the corresponding switch (reference signs from 41 to 58) the corresponding control block (reference signs from 59 to 76) is connected. The beginning of the first winding section 20 through the first key 23 is connected to the first output D of the regulating winding block, and the end of the third winding section 22 is connected to the second output D of the regulating winding block through the sixteenth key 38; At the same time, the beginning of the first winding section 20 through the fourth key 26 and its end through the fifth key 27 are connected to the end of the third winding section 22, the beginning of the second winding section 21 through the sixth key 28 and its end through the seventh key 29 are connected to the end of the third winding section 22, the beginning of the third winding section 22 through the eighth key 30 is connected to the end of the second winding section 21 and through the ninth key 31 - to the beginning of the second winding section 21. The beginning of the third winding section 22 through the tenth key 32 is connected to the end of the first winding section winding 20, and through the eleventh key 33 - to the beginning of the first section of windings 20; the end of the second section of windings 21 through the twelfth key 34 is connected to the end of the first section of windings 20, and through the thirteenth key 35 is connected to its beginning. The beginning of the second section of windings 21 through the fourteenth key 36 is connected to the end of the first winding 20, and through the fifteenth key 37 is connected to its beginning. The end of the first winding section 20 through the second key 24 and the end of the second winding section 21 through the third key 25 are connected to the first output D of the regulating winding block, and the beginning of the second winding section 21 through the seventeenth key 39 and the beginning of the third winding section 22 through the eighteenth key 40 are connected to the second output D of the regulating winding block.

The device shown in Fig. 1 works as follows

At the inputs of this device, i.e. at the primary windings (4 - for phase A, 5 - for phase B and 6 - for phase C, located respectively on the first 1, the second 2 and the third 3 rods of the transformer core), voltage U1 is supplied from a three-phase power source. On the secondary windings (7 - for phase A, 8 - for phase B and 9 - for phase C), as well as on all windings of the regulating winding blocks (for phase A - the first 10, the second 11 and the third 12; for phase B - the fourth 13, the fifth 14 and the sixth 15; for phase C - the seventh 16, the eighth 17 and the ninth 18) voltages appear, the values of which correspond to the transformation coefficients. The output voltages for each phase represent the sum of four voltages: the voltage of the secondary winding U2 and the voltages of the three blocks of regulating windings (of this phase U3 and the voltages U4, U5 of the blocks of regulating windings of the other two phases), for phase A - the voltage on the secondary winding 7 of phase A, as well as the voltage of the first 10, the fifth 14 and the eighth 17 blocks of regulating windings, for phase B - the voltage on the secondary winding 8 of phase B, as well as the voltage of the fourth 13, the second 11 and the ninth 18 blocks of regulating windings and for phase C - the voltage on the secondary winding 9 of phase C, as well as the voltage of the seventh 16, the sixth 15 and the third 12 blocks of regulating windings adjustment.

The operator, based on the indications of the measuring instruments, determines the voltage values for each of the blocks of regulating windings required for a particular phase, as well as what phases of their voltages should be in relation to the voltage on the secondary winding of this phase (in phase or antiphase). Then, using the set of switches according to a pre-obtained table (Fig. 2 and the description of the operation of the block of regulating windings), the operator sets the required values and phases of the voltages on each block of regulating windings. In this case, the regulation can be carried out separately for each phase - in relation to the amplitude (the first 10, the fourth 13 and the seventh 16 blocks of regulating windings), as well as in relation to the phase (the combination of voltages of two blocks of regulating windings, the voltage vectors of which are located at an angle of 120° and 240° relative to the voltage vector of the phase they regulate, since their windings are located on the rods of other phases of the transformer core), thus the possibility of adjusting an asymmetric load to ensure its connection to a three-phase symmetrical energy source is achieved, i.e. the problem of the invention is solved.

The regulating winding block (fig. 2) works as follows

The magnetic flux from the rods 1, 2, 3 of the transformer core excites voltages in the first 20, the second 21 and the third 22 sections of the windings, which are located on this side of the rod 19. The ratio of the voltage values between them is 1:3:9. This makes it possible to obtain the required voltage values in steps equal to the voltage on the first section of the windingUi, varying fromUila 13Ui, both in phase and antiphase with respect to the voltage on the secondary winding of this phase. The combination of switching on the winding sections is carried out by the corresponding electronic keys, which receive opening commands from the control blocks through the necessary switches, turned on by the operator. For example, to obtain from this block of regulating windings a phase voltage Ui, it is necessary to turn on the first switch 41, through which the signal from the first control block 59 will open the first electronic key 23; turn on the fifth switch 45, through which the signal from the fifth control block 63 will open the fifth electronic key 27; and also turn on the sixteenth switch 56, through which the signal from the sixteenth control block 74 will open the sixteenth electronic key 38.

To obtain from the first, fourth and seventh blocks of regulating windings other voltage values, which are in phase with the voltage on the secondary winding of this phase, the starting combinations of switches indicated in Table 1 are used, and to obtain antiphase voltages - the starting combinations of switches indicated in Table 2. To obtain voltages that increase the voltage of the given phase from the remaining blocks of regulating windings, the starting combinations of switches indicated in Table 2 are used, and to obtain voltages that reduce the voltage of the given phase, the starting combinations of switches indicated in Table 1 are used. This is due to the fact that the voltage vectors of other phases are located at angles of 120° and 240° to the voltage vector of the given phase.

Table 1

The value of the voltage on the D bus and the method of its formation. The numbers of switches to be turned on and their reference signs in fig. 2 Ui= Ui(first winding section 20) first 41, fifth 45 and sixteenth 56 2 Ui= (3-1) Ui second 42, seventh 47, fifteenth 55 and sixteenth 56 3 Ui= 3Ui(second winding section 21) first 41, seventh 47, fifteenth 55 and sixteenth 56 4 Ui= (3+1) Ui first 41, seventh 47, fourteenth 54 and sixteenth 56 5 Ui=(9-3-1) Ui third 52, eleventh 60, fourteenth 54 and sixteenth 56 6 Ui= (9-3) Ui third 43, ninth 49 and sixteenth 56 7 Ui= (9-3+1) Ui first 41, ninth 49, twelfth 52 and sixteenth 56 8 Ui= (9-1) Ui second 42, eleventh 51 and sixteenth 56 9 Ui= 9Ui(third section of windings 22) first 41, eleventh 51 and sixteenth 56 10 Ui= (9+1) Ui first 41, tenth 50 and sixteenth 56 11 Ui=(9+3-1) Ui the second 42, the eighth 48, the fifteenth 55 and the sixteenth 56 12 Ui= (9+3) Ui the first 41, the eighth 48, the fifteenth 55 and the sixteenth 56 13 Ui= (9+3+1) Ui the first 50, the eighth 48, the fourteenth 54 and the sixteenth 56

The switch numbers indicated in the tables allow the winding sections to be connected via the corresponding electronic switches in the required circuit. The electronic switches are opened by signals from the control blocks as follows:

through the first switch 41 the first control block 59 opens the first key 23;

through the second switch 42 the second control block 60 opens the second key 24;

through the third switch 43 the third control block 61 opens the third key 25;

through the fourth switch 44 the fourth control block 62 opens the fourth key 26;

through the fifth switch 45 the fifth control block 63 opens the fifth key 27;

through the sixth switch 46 the sixth control block 64 opens the sixth key 28;

through the seventh switch 47 the seventh control block 65 opens the seventh key 29;

through the eighth switch 48 the eighth control block 66 opens the eighth key 30;

through the ninth switch 49 the ninth control block 67 opens the ninth key 31;

through the tenth switch 50 the tenth control block 68 opens the tenth key 32;

through the eleventh switch 51 the eleventh control block 69 opens the eleventh key 33;

through the twelfth switch 52 the twelfth control block 70 opens the twelfth key 34;

through the thirteenth switch 53 the thirteenth control block 71 opens the thirteenth key 35;

through the fourteenth switch 54 the fourteenth control block 72 opens the fourteenth key 36;

through the fifteenth switch 55 the fifteenth control block 73 opens the fifteenth key 37;

through the sixteenth switch 56 the sixteenth control block 74 opens the sixteenth key 38;

through the seventeenth switch 57 the seventeenth control block 75 opens the seventeenth key 39;

through the eighteenth switch 58 the eighteenth control block 76 opens the eighteenth key 40.

Table 2

The value of the voltage on the D bus and the method of its formation. The numbers of switches to be turned on and their reference signs in fig. 2 -Ui= -Ui(reverse connection of the first winding section 20) the second 42, the fourth 44 and the sixteenth 56 -2 Ui= -(3-1) Ui the third 43, the fifth 45, the fifteenth 55 and the sixteenth 56 -3 Ui= -3Ui(reverse connection of the second winding section 21) the third 43 and the seventeenth 57 -4 Ui= -(3+1) Ui the third 43, the fourth 44, the fourteenth 54 and the sixteenth 56 -5 Ui= -(9-3-1) Ui the first 41, the seventh 47, the fourteenth 54 and the eighteenth 58 -6 Ui= -(9-3) Ui first 41, the seventh 47, the fifteenth 55 and the eighteenth 58 -7 Ui= -(9-3+1) Ui second 42, the seventh 47, the fifteenth 55 and the eighteenth 58 -8 Ui= -(9-1) Ui first 41, the fifth 45 and the eighteenth 58 -9 Ui= -9Ui(reverse connection of the third winding section 22) first 41, the fourth 44 and the eighteenth 58 -10 Ui= -(9+1) Ui second 42, the fourth 44 and the eighteenth 58 -11 Ui= -(9+3-1) Ui first 41, the sixth 46, the twelfth 52 and the eighteenth 58 -12 Ui= -(9+3) Ui third 43, the sixth 46 and the eighteenth 58 -13 Ui= -(9+3+1) Ui second 42, the sixth 46, the thirteenth 53 and the eighteenth 58

Thus, in the claimed device, it is possible to separately set the required voltage and phase shift in each phase, which makes it possible to adjust an asymmetric load to ensure its connection to a three-phase symmetrical power source, i.e. the problem of the invention is solved.

1. MD 3823 F1 2009.01.31

2. MD 4397 B1 2016.01.31

Claims (1)

Transformer device for connecting an asymmetric load to a three-phase power supply, which contains a transformer with primary and secondary windings, located in pairs on the rods of the transformer core, corresponding to phases A, B, C, as well as nine identical blocks of regulating windings, while the windings of the first, second and third blocks of regulating windings are located on the rod of phase A of the transformer core, the windings of the fourth, fifth and sixth blocks of regulating windings - on the rod of phase B of the transformer core and the windings of the seventh, eighth and ninth blocks of regulating windings - on the rod of phase C of the transformer core; the secondary winding of phase A, as well as the first, fifth and eighth blocks of regulating windings are connected in series, this circuit representing the output of phase A; the secondary winding of phase B, as well as the fourth, second and ninth blocks of regulating windings are connected in series, this circuit representing the output of phase B; the secondary winding of phase C, as well as the seventh, sixth and third blocks of regulating windings are connected in series, this circuit representing the output of phase C; at the same time, the outputs of these phases are intended for connection to the consumer; each block of regulating windings contains three winding sections: the first, the second and the third with the ratio of the number of turns 1:3:9, as well as eighteen identical electronic keys, to the control inputs of each key being connected by a corresponding switch one control block, at the same time the beginning of the first winding section is connected by the first key to the first output of the block of regulating windings, and the end of the third winding section is connected by the sixteenth key to the second output of the block of regulating windings; the beginning of the first winding section by the fourth key and its end by the fifth key are connected to the end of the third winding section; the beginning of the second winding section through the sixth key and its end through the seventh key are connected to the end of the third winding section; the beginning of the third winding section through the eighth key is connected to the end of the second winding section and through the ninth key - to the beginning of the second winding section; the beginning of the third winding section through the tenth key is connected to the end of the first winding section, and through the eleventh key - to the beginning of the first winding section; the end of the second winding section through the twelfth key is connected to the end of the first winding section and through the thirteenth key is connected to its beginning; the beginning of the second winding section through the fourteenth key is connected to the end of the first winding section, and through the fifteenth key is connected to its beginning; the end of the first winding section through the second key and the end of the second winding section through the third key are connected to the first output of the regulating winding block, and the beginning of the second winding section through the seventeenth key and the beginning of the third winding section through the eighteenth key are connected to the second output of the regulating winding block.