SU537334A1 - AC Voltage Regulator - Google Patents

Description

AC voltage regulator; in fig. 2 shows possible embodiments of sections of the secondary winding with key elements; in fig. 3 - timing diagrams for the operation of the device.

The stabilizer contains a booster transformer 1, the primary winding of which through an inverter 2 is connected to the input terminals, a key bridge 3, one diagonal of which, consisting of keys 4, 5, is connected in series with the output of the stabilizer. The other diagonal of the key bridge 3 consists of sections 6 connected in series, which include the secondary winding 7 (there may be windings with outlets) of a booster transformer 1 and keys 8, the control inputs of which are connected to the outputs of the control unit 9. In this case, in series with the sections MI 6 of the secondary winding of the Booster transformer 1 and the output of the stabilizer include additionally inserted current sensors 10 connected to the inputs of the control unit 9. The stabilizer also contains the load 11.

In closed sections of the circuits there is no short circuit in the operating modes of operation.

The device works as follows.

The input alternating voltage t / in {fig. 3, a) is supplied to the inverter 2 and converted to an increased frequency voltage, which on the secondary divided windings 7 of the booster transformer 1 has the form shown in FIG. 3, b and c, respectively, for the right and left branches of sections 6 of the diagonal of the bridge 3. The branches of sections 6 operate periodically, respectively, with half-periods of the voltage of increased frequency. The total voltage of the series-connected sections in the bridge diagonal can vary discretely and have a number of levels depending on the state of the keys 8, to which control signals from the control unit 9 are applied. Under the influence of the signals of the control unit 9 depending on the output voltage Lout on the clamps of the diagonal of the sections, a voltage is formed which is necessary to compensate for the deviation / out from the predetermined level.

Let the keys 4 of bridge 3 be for operation in the positive half-period of the input voltage, and the keys 5 in the negative half (the polarity of the voltage on the windings 7 and at the input f / Bx in the initial half-period of the voltage of increased frequency corresponds to that indicated in Fig. 1). Then the output voltage t / out of the device is formed by the addition of the voltage f / in with the voltage of the positive half-periods of the divided subsections of the diagonal of bridge 3 (Fig. 3, d). FIG. 3, g, the letters “P and“ L denote, respectively, the right and left working branches of the separated connections. The synchronization of the operation of the device is carried out by current sensors 10,

acting on block 9 at the time of transition of currents through the zero level.

The dashed line in FIG. 3, b and 0 show some of the whole range of total levels.

section stresses b.

Thus, at the output of the device, we obtain a predetermined level of the output voltage (Fig. 3, d), the shape of which almost repeats the shape of the input voltage. The amount of radio interference in the proposed device is much less than in the known. This can be explained by the fact that the current along the branches of the m sections always flows in one direction along the diagonal of the bridge, and the switching is carried out

only from a branch to a branch of sections 6. If, say, a current flows along the right branch of section 6, the left branch first turns on and only this inclusion causes the right branch to lock up under the effect of reverse voltage. (Note that in the well-known version, it is necessary to interrupt the current first, and then it is possible to switch over). This happens only at the moments of switching sections branches when the sign of the signal of an increased frequency changes to

a specific zone, either at the end of the half period, or at the beginning of the next one (which depends on the inclusion of sections for addition or subtraction).

With pulse width modulation such

The cases are limited due to the very principle of PWM stabilization, in which the switching time is determined by the output voltage error signal from a given level and cannot be chosen as desired.

Claims (2)

1. Auth. St. No. 291300, cl. H 02R 13/16, 1969. 2. Kobzev A. V. and others. Characteristics of converter systems with regulating organs of alternating current in the high-frequency link. In Proc .: Current tasks of converting equipment. Kiev, 1975, v. 3, p. 320- 325 (prototype). five V, SK + eleven W 10 10