RU31074U1 - DC voltage source with 12x ripple frequency - Google Patents

Description

DC VOLTAGE SOURCE WITH 12 - TI TIME

PULSE FREQUENCY

The utility model relates to electrical and non-educational power engineering and is intended for converting alternating voltage to direct for supplying direct current consumers that do not allow large ripples of rectified voltage, or when powered from an alternating voltage network, which are critical for the effect of converters on them.

A known source of constant voltage with a 72-fold ripple frequency, containing a three-phase transformer source of variable voltages and two three-phase valve bridges connected in series 1.

The disadvantage of this device is the large number of series-connected valves, streamlined by the full load current, which creates large losses in the bridge valves and significantly reduces the efficiency of the source as a whole.

Closest to the utility model adopted for the prototype is a constant voltage source with a 72-fold ripple frequency, consisting of a three-phase transformer with one primary and two secondary winding systems, the first secondary winding system of which is connected to a star, and the second to a triangle and two

three-phase valve bridges assembled according to the Larionov circuit, the terminals of each system of the secondary windings of the transformer are connected to the different shoulders of one of the valve bridges in places of serial connection of the valves, both valve bridges are connected together in series, forming unidirectional switching of the valves, and the free terminals of the valve bridges form the output conclusions devices 2.

M. Cl. H 02 M 7/08

The disadvantage of this device is the presence of four series-connected valves in the DC circuit, which leads to large losses in the valves of the bridges and, as a consequence, low efficiency of the device.

The objective of the utility model is to create a constant voltage source with a 72-fold ripple frequency with a reduced number of series-connected valves in the DC circuit and have its higher 1SPD.

This task is achieved by the fact that a constant voltage source with a 72-fold ripple frequency contains a three-phase transformer and twelve valves, while on the transformer rods it is placed; one primary and two secondary winding systems are formed, which form connections into a star and a triangle, the conclusions of each of of these secondary winding systems are connected to a three-arm bridge consisting of three chains formed by the serial connection of three unidirectional valves, the extreme electrodes of the valves of the three-arm bridge are connected are connected together and form the output terminals of the device, and the conclusions of the secondary windings connected to a star and a triangle are connected to different shoulders of the bridge so that the conclusions of the windings assembled in a star are connected through one valve from the negative terminal of the device, and the conclusions of the windings assembled in a triangle are included through one valve from the positive terminal of the device, in addition, the terminals of phases a and from the windings assembled in a star are connected to the extreme chains of the three-armed bridge, and the terminal of phase b is connected respectively to the middle chain t a rehanded bridge, and the terminals of the phases of the quince windings assembled in a triangle are also connected to the extreme chains of the three-armed bridge, but the phase a of these windings must be connected to the opposite extreme arm of the bridge in comparison with the terminals of the windings connected to the star, and the phase output c connected to the middle chain of the three-armed bridge, in addition, the phases

a, b, c of the windings assembled in a star are connected using single gates connected by anodes to these terminals, respectively, with the terminals of phases c, a, in the windings assembled in a triangle.

In Fig. 1, a constant voltage source with a 72-fold ripple frequency contains a three-phase transformer 1, the primary windings 2, 3, 4 of which are connected to a star and connected to phases A, B, C of a three-phase supply network and two secondary winding systems 5, 6 , 7 connected in a star and 8, 9, 10 connected in a triangle and twelve valves 11 ... 22, and nine unidirectional valves And ... 19 form a three-arm bridge, each shoulder of which consists of three series-connected valves, respectively 11 ... 13, 14 ... 16, 17 ... 19, extreme electrodes of valves the re-shoulder bridge 11, 14, 17 and 13, 16, 19 are connected together and form respectively the anode 23 and cathode 24 outputs of the device to which the load 25 is connected, the conclusions of the windings 5, 6, 7 connected to the star are connected to the three-arm bridge, respectively points 26, 27, 28, and the terminals of the windings 8, 9, 10 connected in a triangle are connected at points 29, 30, 31 of the three-arm bridge, between the terminals of the windings 5i10; 6i8; 7i9 single valves are connected, respectively, 20, 21, 22, the anodes of which connected to the windings 5, 6, 7.

In FIG. 2, FIG. 3 and FIG. 4, the principle of operation of the device is illustrated by wave and vector diagrams, as well as the table that shows the algorithm of operation of the valves and transformer windings for each time interval equal to 30 el. hail, and corresponding to one pulsation of the rectified voltage.

Here Ualb, UbIcI, UclaJ, Ua2b2, Ub2c2, Uc2a2 LINE VOLTAGE,

acting between the terminals al, b, c1 and a2, b2, c2 is ... o are the currents flowing through the windings 5 ... 10, and i l s are the currents flowing through the windings 2, 3, 4 of the three-phase transformer 1; w is the rectified voltage curve.

shi

The table shows that the valves 12, 15, 18 are in a conductive state of 30 el. hail, for rectification non-period G, corresponding to the working frequency of a three-phase network, valves 20 ... 22 conduct a current of 90 el. hail., and valves And, 13, 14, 16, 17, 19 conduct a current of 120 el. hail. In this case, the optimal duration of the windings is achieved, which is 240 el. deg., as for equivalent multi-pulse rectification schemes, which contributes to the good use of the typical power of a three-phase transformer 1, which is 1.047 of the rectified power, and the number of series-connected valves in the DC circuit is reduced by one valve and is only three valves.

The reduction in the number of series-connected valves in the DC circuit leads to a reduction in active power losses in rectifiers by 25% compared with losses in the known rectifiers 2, the use of common wiring diagrams of transformer windings and the efficient use of their typical power reduces the costs associated with the manufacture of this device, and determines its wide scope, for example, in traction substations of electric vehicles.

Sources of information:

1. Shlyaposhnikov B.M., Ignitron rectifiers. M .: State Transport Railway Publishing House, 1947.-736 p.

2. Twelve-pulse semiconductor rectifiers of traction substations / B. S. Barkovsky, G. S. Magay, V. P. Matsenko and others; Ed. M.G. Shalimova.-M.: Transport, 1990.-127 p.

Sh.

Claims (1)

A DC voltage source with a 12-fold ripple frequency, containing a three-phase transformer and twelve valves, while on the transformer rods there are one primary and two secondary winding systems, one of which is connected to a star and the other to a triangle, characterized in that the conclusions of each of of these winding systems are connected to a three-arm bridge, consisting of three chains formed by the serial connection of three unidirectional valves, the extreme electrodes of the valves of the three-arm bridge are connected together and form the output terminals of the device, and the conclusions of the secondary windings connected in a star and a triangle are connected to different shoulders of the bridge so that the conclusions of the windings assembled in a star are connected through one valve from the negative terminal of the device, and the conclusions of other windings assembled in a triangle are connected through one valve from the positive terminal of the device, in addition, the terminals of phases a and from the windings assembled in a star are connected to the extreme chains of the three-armed bridge, and the terminal of phase b is connected respectively to the middle chain of the three-armed bridge This, moreover, the conclusions of phases a and b of the windings assembled in a triangle are also connected to the extreme chains of the three-arm bridge, but the phase a of these windings must be connected to the opposite extreme shoulder of the bridge compared to the conclusions of the windings connected to the star, and the phase output c is connected to the middle chain of the three-armed bridge, in addition, the terminals of phases a, b, c of the windings assembled in a star are connected using single valves connected by anodes to these terminals with the terminals of phases c, a, b of the windings assembled in a triangle, respectively.