SU477508A1 - Three phase inverter - Google Patents

Description

(54) THREE-PHASE INVERTER

The invention relates to educational devices and can be used in electrical systems and electric drives of industrial plants and vehicles.

Three-phase inverters with a width-nm pulse regulation of the output voltage at a carrier frequency several times higher than the output frequency, containing a three-phase power transistor bridge, three control push-pull transistor amplifiers with a transformer output, a three-phase output frequency pulse generator, and a generator of impulses of the frequency carrier are known. and a modulator of the width of these impulses, having for each phase two lars of outputs of the main and complementary impulses of an adjustable duty cycle.

The proposed inverter differs from the known ones in that the clips of one Polarity of each pair of primary and secondary pulses of the modulator of a carrier pulse width are connected to the base of each transistor of the control amplifiers, the clips of the other polarity have different connectors of the same polarity of the other pair of outputs and through the switching keys with emt1tterami of these transistors, and the input “ohm. mutating keys connected to the output of a three-phase generator of high-frequency frequency emulses.

Such an embodiment of the inverter allows it to be increased to j. .d

For the shortage of days and power in the power traisistors, the winding of the output transformers of the first and third, first and second, second and third phases of the three-phase generator are connected and connected via resistors and diodes to the inputs of transistors of control amplifiers of the same-phase phases.

On fi1. 1 given the scheme described inverter; in fig. 2 - inverters voltage inverters; in fig. 3 is a variant of the inverter circuit with a unipolar form of carrier IMI pulses during the nun period of the output nation; FIG. 4 - voltage plots of this inverter.

The inverter (CjM. Fig. 1) contains a three-phase bridge of TI-Te power transistors, three controllers of two-stroke transistor drives with a transformer output (one each phase), made

Tn Te transistors with a transformer Tp Te and Tyu transistors with a transformer Trg n Tc and Ti2 traizistors with a Trz transformer, a three-phase oscillator f / i-L / s. the output frequency of the AG | -AHZ, the scattering generator of the ZG pulses {Unsun frequency, in

several times higher than the output frequency, the PWM modulator width of the carrier pulses, having for each phase two pairs of outputs of the main C / y and the supplementary Ul - Y pulses of an adjustable duty cycle. For example, in the phase of Anerazu pair there are the outputs of the rectifiers D2 and DB, De, and the second - the outputs of the rectifiers Dt, Dv and Dz, D4. From the outputs of the rectifiers D5, D and D, Dz, the main ones are removed, and from the outputs of the rectifiers D1, Dzn Dz, D4 - the complementary nmulses. The terminals of the same floor (for example, negative) of each output bins are connected through resistors to the bases of the iiipeji amplifier of the transistor. The anode terminals of the D, Yes, DB and DB diodes, which represent negative voltage clamps, are connected through resistors to the base of the transistor T, and the anodes of the diodes Dt, Yes, Dz, and D4 - to the base of the transistor TS.

The common branches of the windings W and W, Wcj and Wio form the terminals of positive polarity of the outputs of the main circuits, and the common terminals of the windings W and W, Wz and W are the terminals of the positive pole outputs of the complementary pulses. The positive polarity terminals of each pair of outputs are connected to different terminals of the same zero of the other output bins and through the switching keys to the emitters of the preamplifier transistors: in phase A, the terminals of the outputs of the main pulses are connected to the terminals of the outputs of the donating pulses and to the collectors of the transistors TP and Tm commuting keys.

The inputs of the switching keys and connected to the outputs of the three-phase generator, ianrnmer I phase A of the base trans 11 stori1 1x keys Ti3 and Tj4 are connected to the outputs of the transformer Tr. Schemes of unrvlmshm amplifier mn phases of VnSViiu.tpsny anl.yu-typically scheme of phase A.

11Ne Lor works in the following ways.

The high voltage of the sprat-impulse modulator (cfm fng. 2) is rectified by diodes D - C, resulting in the formation of the main nm / f pulses. The duty cycle of these i.nulses is U TP / T, where T is the pulse duration. T - ieriod ian) Issui her frequency. Complementary nm-pulses Ugu mogug form1 (-inov1 with different methods, nAlMil, 1 stretch; || 1m winding turned on - W output1) ansformat () I set the centr of the generator n windings. Wla slit-imiou modulator. Formed in such a way that the voltage f / i-y is exhausted. 1a-mn D | -D |, in |) as a result: h) forms pre-waves | () and; pulses with a duty cycle of 1-y.

Primary and doaoli ui1e nmnu1nc1 1 are used to control transistors usgglnthe chip at IIOMOHUI KOMMyTJijiyioiuHX klyug

whose ones switch with (output frequency out of phase with the voltages of the corresponding AFi-AGZ autoheaters (Uiz n Ut t / i. |)), open n), Ti3 (transistor Ti.i closed), then during the semi-tuner T / 2 voltage of the output frequency) through the resistors and the base of the tra 3 stor of the T main Schm1 pulse15 is the 1st negative of the polarity, and the base of the transistor

Tg - Dopol I Exalted M pulses of a negative 1 iol matte. The next transducer of the oscillating frequency OTK1), the transistor TU (transistor Tyu closes), as a result of which the transistor Tg and the base of the transistor Tg and the axes of the transistor T are large additional pulses. In the pauses between the pulses, the transistor T i TS is, as usual, through the resistors from the source of the f / cM bias, as a result of which the transitions between the base and the emulator of these 3 3 tori wires are formed on April 1, U6 and W, duty cycle)

negative)

The frequency looper) is equal to Y and 1-Y in the other. Collector apronsch uk p LKS also deducted from the inspector ostnmnulso} ch1) food1ONiys wellbore in the nolperiodu, and 1 - Ystorystor Tdn Tyu, TTz and Tjo, whose, in other phases, other patterns, patterns, patterns, patterns, and other components, patterns, patterns, patterns, and other patterns, will be used by other phases, patterns, chips, tees, and other circuitry will be used. from shift 0 to period T of the output a1: p, as in any three-phase system with a ratio of f / Kg and t / Kio.

In that half of the period T, in which the trapsistor TU opens with a well of Y. leva primary 1a, the semi-winding of the transformer Tr) connects to the supply voltage also from the wellness 0 Y. e of the right - with a duty cycle of 1-Y following common semi-toner1To / 2, on the other hand, the right half winding is connected to the nostochnu 1ku SO, the dvigage is 1 0 Y. and the left is with the duty cycle 1-y. Similarly, the work from the tra1 transformer of other phases, therefore the mode) works) of the transformers

in POLUNERIODA SIMMSTRICHPP) I 1 ODMaGPICHIvayne nh hearts there are no hearts.

Transistors of each amplifier, 1 traznstor anrimer) T n TS, alternately (pair zon1 L.K. and Vkv), but therefore at any time nz semi-winding of the transformer Tpi-Trz to the source of the I-type filament and from the secondary) windings and the base of the forces) X transistors, for example, a TI 1 transistor, THERE ARE TURNING P1I,

 However, c) a form as 1 arr zs 1 (Ubu and Review. When it is. Amnesty convertible nozel n. 1x I de 1 the first impulse of the first pulses is the same.

Etc. ns bore 10C and from about to 1 all as a plover nx, ak is the center of the pulses; 1 (; STANDING; 1, М1 (.

Due to this, the amount of solids in the base Tssan can be reduced.

The shape of the inverse collector-emntger of power transistors, the iririmer on; 1pl ennn LKI-UK ,,, replicates the form of analog voltages Uirav11, its amplifiers. As a result, for example, when the load is connected to a “triangle”, the output diagrams UA, IJu and Lc of the three-phase bridge of the power transistors have the form of pulse pulses with a loading duration of 2/37. Therefore, the average f / cp of the output voltages and A, ie, and c (Fig. 2 is shown by the iuktir), is determined by the ratio of the durations of Nolozhny and N negative imiuls, i. E. , at 1 Ucp, the gross duty ratio of the impeller of the pulse-shunting modulator is determined by the cingular Uy at its input,;: 1 therefore, the average output voltage of the load is determined with the control signal Ly.

In order to reduce the power loss caused by the disconnection of the transhynchronous processes, a three-phase inverter circuit with a single-line pulse shape and a driving frequency during the half-cycle of the output voltage is proposed (see Fig. 3). Accord including windings W | n W Tpi transformers. and Tros three-phase generator of the first and third phases through

resistors n DNODA Do, Dz and Dd, D12 IODKLYucheny to the bases of the transistors T, Tg n TC, Ti2 of the same-name nedvarnteltelyh amplifiers, ie, to the transistors unravl 10I1hh amplifiers of the first and third phases.

Similarly, according to the connected windings Wz and W, W and W of the transformers Tpi and Tr2 of the three-phase generator of the first and third phases through the resistors of the n diodes Dd D4 and DH, D are connected to the bases of the transistors T, Te and T, T; about single amplifiers. According to the included windings Ws and W. of transformers Tra n Trz of the second and third phases through resistors and diodes D.-, Dv and Du, Dn are connected to the bases of transistors Td, T) o and Tc, Ti2 of all-mode amplifiers.

The pair of windings of the same preamplifier is included with respect to each other. Nastrimer, a pair of windings Wi of the Tpi and Gtr transformers are connected to the diodes Yes and Dd by the end of the winding, and a pair of windings W of the same trapsformers and a switch to the diodes Dz and D12 and the winding shaft.

Each pair of voltages are connected to the windings of the circuit and connected to the emitters of transistors of preamplifiers. The connection points of the diodes D and D2, Dz and D, Dg, and De, D and D8, D0 and Dy, D and D12, respectively, through the resistors Ri and Ra and Rt, Rs and R are connected to the base of transistors T | n TU, TIS and TIG, Ti7 n TIS switching keys.

From Tpi-Trz transformers (see fig. 4)

sn1 ayuts shifted by 120 e. hail, napr. As a result of the summation of these voltages in each pair of agreed-on windings, f / jjLa, fya + f s-n t / i + 62 formations are formed. Thus, a pair of windings W, n 2, Wz and Wi, W4 and W., Wz and G., the keys are opposite, then the stresses, simenemye with them, are shifted by 180 °. D; -D12 diodes on the base of traisistors;

and switching cells, only negative impulses.

Thus, three types of negative imiuls enter the bases of transistors of preamplifiers: the main ones, additionally according to the included windings.

G; -G4.

In the first half-period of the voltage Ui, the base of the Ti3 transistor from the secondary winding of the Tpi tracer is fed a negative imuil. Transistor Tn locked positive pulse. Ajar Ti3 transistor to the base of the transistor Tt, the main ones, and to the base of the transistor Tg - additional impulses. When the impulse f / i-j-t / a is negatively negative, the Ti3 transistor is locked. Consequently, the base transistors Tn TS do not receive either the main or the complementary pulses. At the same time, the transistor Tg is locked by an external mix, such as the voltage across the windings IFg of the Tpi n Tp transformers is positive with respect to the cathode of the Dz polarity and locks it.

The transistor Tu opens with a voltage pulse t / i + Ls for the time T / 6 (voltage, / 67 n U6s). In the next time interval T / 6, the voltages and + IzHt / i-fL have a pause, and the transistors Ty and Tg are controlled by the main and complementary pulses, the non-frequency. On the third interval T / 6, the transistors Tu and TIS are controlled by a pulse of Ui - {- L2 nanoparticles, which stay on their base through diode D in the second half period 1: the process is not symmetric.

The other two preamplifiers work similarly, but with a phase shift of 120 e. hail.

At any point in time, the output transformers are connected to the power supply unit, so these transformers transfer voltages from the primary windings to the secondary ones without distortion, with the result that iaire lines on the basic windings of the Ti-T power transistors have the same shape as , according to, t / bu-L6i2 on the bases of the transistors of the amplifiers.

On the shipping included in the “triangle,

at the output of the inverter, f / l, UB and Uc pairs are formed with unipolar for

i-type output voltage form

pulse 1V and the frequency.

In contrast to the scheme “and FIG. 1 in which ia

any period interval is switched

the high carrier frequency is often all three pairs of transistors Tj and T-, Tz and T4, T and TG, in the circuit. : iia FIG. 3 at any interval iiej) iio; ia with duration G / 6, only one aara transistor switches to iiecyoicii frequency. Since the main bottom of the semiconductor losses in the silovol: the bridge appears nmenno because of: ne) 1 transistors with a carrier frequency are disconnected, these losses in the circuit in FIG. 3 is approximately three times less than in the scheme for fng. one.

PRI TEM

1. Three-phase invertor with shi1) relative-impulse regulation of the output voltage at the carrier frequency, several K13 higher than the output frequency, containing a three-phase power transistor, three control two-stroke switching power amplifiers with transformer output :, a three-phase pulse generator output-output transistors with transformer output :, a three-phase pulse generator output-output transistors with transformer output :, a three-phase pulse generator output-output transistors, with transformer output: master oscillator of impulses of nonadjustable frequencies and modulator tor of these PMZhfosch and

)

Jf

pulses, pmeyun1, for each phase are two bunks of the outputs of the main and auxiliary pulses ()) with constant 11) duty cycle, characterized in that. for the purpose of raising d., clamps of one iolarity of each type of outputs of the main and complementary modules of the modulator connectors with the base of each of the transistors of the control amplifier, clamps of the other polarity with opposite terminals

0 the same polarity another pair of watches and through

commutating switches with these

a transistor, and the input is a switch

connection 1) 1khod1M three phase generator.

2. And | 1ve |) tor but p. I, the difference is

5 that, in order to reduce the dynamic and power losses in the power transistors, sequentially and according to the switching windings of the output of the traisformat module, the nerve and the third, first and second, second and third phases of the three-phase geierator are connected via resistors and diodes to the inputs of the tractors of the coupling amplifiers of the single-pulse phases.

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