RU1812606C - Converter which outputs alternating voltage having given shape - Google Patents

Abstract

Usage: converting a multiphase input AC voltage to a single or three phase voltage of a different frequency for secondary power supply systems or electric drives. SUMMARY OF THE INVENTION: bridge cells with individual transformers are connected to input terminals. The output voltages of a group of cells are summed at the input of the demodulators. The outputs of the demodulators are summed over the current using a filter transformer that simultaneously filters the higher harmonics. 1 s.p. f-ly, 8 ill.

Description

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The invention relates to a conversion technique and can be used in the construction of secondary power sources of both centralized and decentralized types for converting the initial multiphase alternating or constant voltage to the voltage of the desired shape, single or multiphase, especially in those cases in which an increased quality of output voltage and load current, coordination of supply and consumer voltage levels, regulation over wide limits or stabilization of output voltage while providing a high-current output and restrictions on weight and size indicators.

The purpose of the invention is to expand the functionality by introducing, along with the constant alternating supply voltage, without deteriorating the quality of the output voltage and by forming a multiphase voltage system at its output.

The introduction of additional bridge inverter cells and the connection of their outputs in series in each of the sections formed allows us to introduce, along with the constant, an alternating supply voltage without impairing the quality of the output voltage of the converter, which ensures the expansion of its functionality. The introduction of additional demodulators and additional secondary windings of the output transformers of the inverter cells, as well as additional filter transformers, allows the formation of a multiphase voltage system at the output of the converter, which also provides an extension of its functional capabilities.

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In FIG. Figure 1 shows the power part of the circuit of an AC-to-voltage converter of the required shape with three high-frequency conversion channels () and a three-phase AC supply system (p-3) and with a single-phase output (); in FIG. 2 is a diagram of a control unit of this converter; in FIG. 3 is a diagram explaining the process of forming the control action nor the first demodulator; in FIG. 4 and 5 are diagrams illustrating the process of generating the output voltage of this converter; in FIG. Figures 6 and 7 show the power circuit and voltage diagram of the converter with two channels of high-frequency conversion () and three-phase w | system of supply voltage (see Fig. 8 - the output part of the transformer With a three-phase system of output | | (voltage ().

Rssms) || § riepebi and an example of a specific implementation | re | parent, when. . :}. :. ::; -. .-. . : The converter contains bridge inverters | IDI1-II9 (1-S, FIG. 1), execution ||;: 1 and a bridge circuit on keys with two-sided conductivity (alternating current keys) K1-K4 (10-13) with output matching transformers Tr1-Tr & (14-22) and connected by power inputs to the phases of the supply | g9y1 alternating three-phase () and switchgear; demodulators DM1-DMZ (, to the polyolens, for example, along the bridge (xchё on alternating current keys K5-K0 $ 6-Ј§) and connected by power inputs to series-connected secondary windings of the respective tpl-TPE transformers, and an output high-frequency three-phase () summing filter FT transformer (30) for the practical implementation of a parallel connection of the outputs of demodulators, which actually performs a function. output filter. The output of the filter transformer is in the WBD of the device .; .

The converter control tree includes a frequency control unit 34 (31, Fig. 2) connected in series with each other and a three-channel (with three phases at the output) pulse RI distributor (32) with paraphase outputs: direct p1, p2, p3 and inverse p1, p2, p3. The direct RI outputs are connected to one information inputs of logic cells, respectively, ЛЯ1, ЛЯ2, ЛЯЗ ($ 33-3) and to the information inputs of comparators K1, K2, KZ (36-38), respectively, through sawtooth voltage generators, respectively, ГПН1, ГПН2, ГПНЗ (39-41);

the control inputs of the comparators are combined and connected to the master of the control signal through the rectifier 42. The inverse outputs of the RS are connected to the second

information inputs LA. The control inputs of the aircraft are combined and connected to the control signal master via a PF form converter (43) with a paraphase output F. The outputs of the comparators K1, K2,

0 SCs are connected to the control inputs of logic cells, respectively, Я1, Я2, ЯЗ (44-46). Information inputs Ya1, Ya2. YaZ is connected to the paraphase outputs LYa1, direct L1.L2, LZ and inverse L 1,

5 l, l3 respectively. The outputs of the cells H1-H3 are outputs of the logical node LU1 thus formed (47) and are connected to the control inputs of the corresponding keys of the DM demodulators. Block

The control 0 includes three more () of the same logical nodes LU2, LUZ, LU4 (), the outputs of which are connected to the control inputs of the corresponding keys of the inverter cells of the II, and the inputs are connected

5 to the phases of the supply voltage A, B, C, respectively.

Frequency reference 31, pulse distributor 32, and ramps 39-41 are common to

0 of all logical nodes (LU1-LU4). The internal structure of the logical cells A and I can be different. The specific variant of their circuitry implementation depends on the oir type and nomenclature of the used logical elements. So, for example, ALE contains two logical elements AND 51.52 and one logical element OR 53 and NOT 54, and I - two logical elements 55.56 and NOT 57.58 and one OR element 59.

0 As a second example, simpler, consider a converter with p-Z and pN2.

The power part of such a converter includes only six (tp - 6) bridge inverter cells: ИЯ1-ИЯ6 (1-6, Fig. 6) with output matching transformers Tr1-Tr6 (14-19); only two () demodulators: DM 1, DM2 (23, 24) and the output high-frequency dual-winding summing filter FT filter transformer (60 fig. b). The FT output is the output of the device.

The control unit also includes four (gy-r-4) logical nodes LU1-LU4, but

5 simplified, with two () channels for generating control signals.

As an example of a converter with a multiphase system of output voltages, we consider the case with m «n ip-s3.

. The power part of such a converter includes nine (t p 9) bridge inverter cells ИЯ1-ИЯ9 (1-9, Fig. 1) with output transformers (14-22, Fig. 1 and 8) having three () secondary windings; nine (tp-9) DM1-DM9 demodulators (23-25, 61-66, Fig. 8) and three-phase output () filter transformers FT1-FTZ (30, 67, 68). FT outputs connected in FIG. 8 into a star (other options are possible: for example, into a triangle or separate at all), are the output of the device.

The control unit includes six () logical nodes: three inverter-cell control LUs () and three demodulator control LUs (), each with three () control signal generating channels.

The device () operates as follows.

: The sawtooth voltage generators GPN1-GPNZ (39-41), synchronized by the pulse distributor RI (32) with the output signals p1 and p1 (Fig. 3), p2, p2 and p3, p3 and a frequency master 34 (31), produce reference voltage r1-r3 sawtooth (Fig. H) with a mutual phase shift of 2/3 (generally 2 l / m which are compared on comparators K1-KZ (36-38) with the control signal module Uy, so that the output comparators are generated signals k1 (Fig. 3), k2, c3, Key control signals, for example, DM1 are formed by a logical cell Я1 (Fig. 2) according to the following algorithm TMU (fig.Z):

 k1 + lt-kT, k7 l1,

k6vl1 k1-ylT-kT, lt,

where the signals L1, LT (as well as L2, L2 and L3, L3) are formed by the logical cell ЛЯ1 (ЛЯ2 and ЛЯЗ) according to the following algorithm:

-l1 p1

 + pi-F,

where, in turn: F and F are the output signals (Fig. 3) of the PF shape converter (43) that implements the operation of indicating the polarity of the control signal Uy.

Such key management of the DM1 bridge corresponds to the equivalent modulating effect f 1d (Fig. 3) on the power signal (input voltage) of the bridge. Similarly, the logical node LU1 (47) forms the equivalent modulating effects of 2d and pd on the demodulators DM2 and DMZ and the logical nodes LU2-LU4 (48-50) of the equivalent modulating effects on the inverter cells IY1-IYA9, 5 only control the LU2-LU4 phases supply voltage Ua, 1) b, Uc (Fig. 4).

With this control, at the outputs of the inverter cells (on the secondary windings of the transformers (IN1-INZ (Tr1-TrZ)), high-frequency voltages are generated respectively and (1) rf and (2) rf, (Fig. 4) modulated by the phases of the supply voltage, which are then summed up by connecting the secondary windings Tr1-Tr3

5 sequentially with each other with the formation of a high-frequency already unmodulated voltage U rf. Voltages U RF and UHF are obtained similarly. All of them having a mutual phase shift of 2 LUZ (in the general case, 2 LUt) are fed to the power inputs of the demodulators, respectively, DM 1-DMZ. At the outputs of the demodulators DM 1-DMZ, voltages are formed respectively (Jr (Fig. 4,5), U2®, (Fig. 5), containing

In its composition, in addition to the main (useful) component, which repeats the control signal Uy in form, there are also a number of high-frequency harmonics, the main of which form a three-phase () system. These

0 voltages from the DM outputs are applied to the windings of the three-phase summing filter transformer FT (30) (through the load of the converter). According to the main component (common-mode), the FT operates in a short-circuit mode (its windings turn on in fact in parallel, which is equivalent to a short circuit of a three-phase or, in the general case, m-phase transformer), and the main component without distortion reaches the output converter (though together with other common-mode harmonics). In relation to the main high-frequency harmonics, the FT windings are switched on as usual

5, the star, and FT, retaining on itself all the high-frequency harmonics forming three-phase systems (in general, m-phase), does not pass them to the output of the converter. At the output of the converter, a voltage of improved harmonic composition Ua is generated (Fig. 5), identical in shape to the total output voltage of the DM1-DMZ demodulators and differing from the latter only in three times (m times) amplitude. High frequency voltages are applied to the FT windings; therefore, the mass and dimensions of the FT will be insignificant.

The device (,) (Fig. 6) works in a similar way, the only difference is that there are only two reference voltages (): r1 and r2 are also sawtooth, but with a mutual phase shift, which are also compared on two comparators K1 and K2 with a control signal module Uy with the formation of signals k1 and k2 at its output. There are also two high-frequency unmodulated voltages: U rf and U rf with a mutual phase shift lg / 2, which are fed to the power inputs of two demodulators DM1 and DM2. Voltages Uir are formed at the outputs DM1 and DM2, respectively (Fig. 4.7) and U2® (Fig. 7), containing in addition to the main component a number of high-frequency harmonics, the main of which are mutually antiphase. The output voltage of DM 1 is applied to one winding of the FT summing filter transformer (60) (through the load of the converter), and the voltage from the output of DM2 to the other winding, in antiphase with respect to the first FT winding. In terms of the main component (in-phase), the FC operates in the short-circuit mode (its windings turn on in opposite-parallel mode), and the main component without distortions gets to the output of the converter. With respect to the main high-frequency harmonics, the PT windings turn out to be connected in parallel, which is equivalent to one winding, and the FT, holding all the high-frequency harmonics in antiphase, does not pass them to the output of the converter. A voltage U2 is generated at the output of the converter (Fig. 7).

A converter with a multiphase system of output voltages (mnp-3) works in the same way, only the output voltages of the demodulators are summed using three () FT1-FTZ fusion transformers (Fig. 8) with the formation of three phases A, B, G (and zero phase) at the output.

The transducers of FIG. 1, 6, 8 can also be supplied with direct voltage. To do this, it is enough to combine the terminals A, B, C at the input of the converter (and in the control circuit too), while the resulting circuits will not be critical to the connection of the dc signs, or + apply to the combined terminal ABC, a - - to terminal 0, or vice versa.

The introduction of additional bridge inverter cells and the connection of their outputs in series in each of the sections formed compares favorably with the proposed converter from the specified prototype, since this allows introducing, along with the constant, the alternating supply voltage without affecting the quality of the converter output voltage. In addition, the introduction of additional demodulators and additional secondary windings of the output transformers of the inverter cells, as well as additional filter transformers, allows the formation of a multiphase voltage system at the output of the converter. All this provides an extension of the converter's functionality, highlighting it against the background of the prototype.

The advantages of the described converter should also include the fact that the circuit is insensitive to the frequency of the supply voltage and the frequency of the control signal and can be controlled even by a constant signal sign and even a constant (eg, reference) voltage, thus performed ideal rectifier functions (without non-linear distortion of the output voltage, usually caused by the input alternating voltage). The proposed converter circuit allows you to simply implement discrete (along with continuous, within known limits) regulation of the output voltage over a wide range (m times), for which it is enough to provide for switching the summation of the outputs of the demodulators in parallel with filter transformers to serial over a well-known generalized summation circuit.

Further clarified to the block diagram of the control system of FIG. 2... As follows from the description and timing diagrams in FIG. 3 - FIG. 5, the frequency governor 31 and the pulse distributor 32 (FIG. 2) should be common to all four logical nodes 47-50.

Claims (2)

1. A converter with an alternating voltage output of a given shape, containing m inverters with a transformer output, each of which is connected to the input of the demodulator by the output, the outputs of the m demodulators are connected in parallel using the m-winding summing filter transformer, and the control unit, o Including with the fact that, in order to expand the functionality by using p-phase input alternating voltage and p-phase output voltage, each inverter is made in the form of n bridge cells with individual lnym output transformer having a number of identical secondary windings, wherein each entrance of these cells connected to the input terminal of the corresponding phase of the converter, the number of demodulators is chosen equal to mp, and the number of t-winding summing filter transformers equal to p, the output of each of these filter transformers is connected to the output terminal of the corresponding phase of the converter, each of the windings of a summing filter transformer winding is connected to the output of the corresponding of m demodulators, to the input of each of which is connected a chain of serially connected secondary windings of the individual output transformers bridge cell formatters connected by an input to the input terminals of various phases of the converter, and the control unit is configured to generate pulse-width modulating pulse control keys for inverters and demodulators. :.-.- ;. ; 2. The converter according to claim 1, distinguished by the fact that the control unit contains n + p identical logic nodes, each of which is connected in series with a frequency master and an rn-channel pulse distribution with Various outputs connected via a generator :; ,: -. . . 9 T% sawtooth voltages to the information inputs of m comparators, the control inputs of which are combined and connected through the rectifier to the control / input of the logical node, and the outputs are connected to the control input of the m first logical cells, the information inputs of which are connected to the outputs of the corresponding m second logical cell, the control inputs connected through the form converter to the control input of the logical node, and the information inputs to the corresponding outputs of the m-channel pulse distributor, The outputs of the first logical cells are connected to the outputs of the logical node, the control inputs of the logical nodes are connected to the corresponding phase of the p-phase control voltage regulator, and the outputs of these nodes are connected to the control circuits of the corresponding demodulators, and the control inputs of the remaining logical nodes are connected to the input terminals of the corresponding phases of the converter, and the outputs of these nodes are connected to the control circuits of the corresponding bridge cells of the inverters. hl (Pus, J. tlV School lay fl pifi W Tuud . FIG. S rsch. g FIG. 6 . & -