SU1045341A2 - Three-phase frequency multiplier - Google Patents

Description

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The invention relates to frequency converters, in particular to transformer-type multipliers, and can be used for inia high-speed electric motors of centrifuges, woodworking machines, hand tools. In addition, it can be used for inductive heating, power supply of radio equipment, automation devices and magnetic amplifiers, as well as for EDM processing.

By ocHOBHc iy auth.St. No. 549868 is known a three-phase frequency multiplier comprising a transformer, on the terminals of which are located primary and secondary windings, thyristors and a phase-shifting unit, each having four primary windings combined in two pairs, each of which is closed by a pair. thyristors, the common points of connection of the thyristors of the first and second pairs and the windings of the second pair are connected in accordance with the direct sequence of the phase alternation to the input phase Hb5, and the common connection point of the windings of the first th pair is connected to the zero input terminal.

However, with the active-inductive nature of the load, the power of this multiplier drops sharply, and the range of output voltage regulation decreases. These drawbacks are due to the strong influence of the emf of self-induction with the active-inductive nature of the load.

The purpose of the invention is to increase the power and expansion of the control ranges of the output voltage of the multiplier with the active-inductive nature of the load.

The goal is achieved by the fact that, in a three-phase frequency multiplier, parallel to each of the primary windings, one additionally introduced reverse thyristor is connected, and the control terminals of these thyristors are connected to the additionally introduced control unit.

Fig. 1 shows a schematic diagram of a frequency multiplier two times with a single-phase output; Fig. 2 shows voltage, current and power curves at the output of the multiplier.

The single-phase frequency multiplier consists of thyristors 1-4,. of the coreguard 5, on which the primary windings 6-9 and the secondary winding 10 are located, the phase shifter (FSU) 11, and parallel to each of the primary windings is connected one reverse thyristor 12-15, and the control terminals of these thyristors are connected to the control unit 16.

The multiplier works as follows:

At the moment of time (about t otijrtp (Fig. 2, when DC voltage is positive with respect to thyristor 1), the control signal from FSU 11 and thyristor 1 comes to the latter, opens at the same time, and flows in the primary winding 6 beginning to the end. At the moment of time (ot. 1 (Fig. 2), the voltage u / sg changes sign, thyristor-12 is given a control signal from control unit 16; phenomena, thyristor 12 opens and a current starts flowing through it, The emf of self-induction induced in winding 6 and the thyristor-1 closes. less than the holding current, the thyristor 12 is closed, and then at the time point c.ot - - oiijnp (Fig. 2) the control signal QT of the PSF 11 goes to the thyristor 3. Since the voltage Ugc lags behind the voltage Od on - |,. then it has a positive value with respect to the thyristor 3, the latter opens, and a current begins to flow in the direction from the end j to the winding 8. At the time ut - (Figure 2) the voltage Ug ( ; changes the sign to the thyristor 14, a control signal is supplied from the control unit 16, the thyristor 14 is turned on and a current is flowing through it supporting the self-induced EMF induced in the winding 8, and the thyristor 3 is closed. When the current decreases to a value that is less than the holding current, the thyristor 14 is closed. With this polarity of windings 6 and 8, a period of double frequency is created on the output winding 10.

At the moment of time and t fi -i oL ijnp (Fig. 2), when the voltage idd is positive with respect to the thyristor 2, the last opens after supplying the control signal to it from the FSU 11. Next, the multiplier operates as above , starting from the moment of time oot yupr (Fig, 2

With the indicated polarity of the windings 7 - and 8, a second double frequency period is created on the output winding 10. After the filing of the thyristor 1 s-ignal control. From the FSU 11 at the moment of time w t Chu. + i (jnp cycle repeats.

The frequency multiplier can be performed with a three-phase output.

The three-phase output multiplier includes three multipliers with a single-phase output, while the connection circuit of the primary windings to the supply network is the same as for the proposed multiplier.

The output windings of the three-phase multiplier can be connected into a star or a triangle.

The present invention in comparison with the known one has the following advantages: the power is increased and the control range is expanded.

the output voltage of the multiplier with the active-inductive nature of the load, which leads to an improvement in weight and size parameters.

Claims (1)

THREE-PHASE FREQUENCY FREQUENCY by autosw. I? 549868, characterized in that, in order to increase power and expand the range of regulation of the output voltage with the active-inductive nature of the load, parallel to each of. primary windings are connected via one additional input reverse thyristor, and the control terminals of these thyristors are connected to an additional input control unit. SS SU .... 1045341> 1045341 The multiplier works as follows. At time ω t = eTsgtr (FIG. 2) when the voltage on the positive CSD ^_0/1 with respect to the thyristor, the last control signal supplied by the thyristor 11 and OFS 1. wherein the open and the primary winding 6 begins to flow, the current in direction from [start to end. At time 1-0. iCat = 9 (Fig. 2), the voltage changes sign, the thyristor-12 receives a control signal from the control unit 16, the thyristor 12 opens and the current supported by the self-induction EMF induced in the winding 6 starts to flow through it, and the thyristor-1 closes. When the current decreases to less than the holding current thyristor 12 _L closes at the moment after which time cot. = - + o2u _P r (Fig. 2), the control signal from the FSF 11 is supplied to thyristor 3. Since the voltage Ugc lags the phase U _io by -,. then it has a positive value with respect to thyristor 3, the latter opens, and by winding. 8 starts. flowing current, from the end to the beginning. At the time ut = = (Fig. 2), the voltage U _0C changes sign, the control signal from the control unit 16 is applied to the thyristor 14, the thyristor 14 is turned on, and a current begins to flow through it, supporting the self-induction EMF induced in the winding .8, and the thyristor 3 closes. When the current decreases to a value lower than the holding current, the thyristor 14 closes. With the indicated polarity of the windings 6 and 8, a period of doubled frequency is created on the output winding 10. At time i) t = ίι + ci у _П р (Fig. 2), when the voltage id _{0 is} positive with respect to thyristor 2, the latter opens after a control signal from FSU 11 is applied to it. Next, the operation of the multiplier occurs similarly to the above, starting since time _ωί = _{с0 уП} р (Fig.2). With the indicated polarity of the windings 7-8, a second period of doubled frequency is created on the output winding 10. After applying · to the thyristor 1 the control signal. From FSU 11 at the time ω t = 2 '!?. + o (tjnp cycle repeats.