SU920981A1 - Single-channel master generator of frequency of cycloconverter output voltage - Google Patents

Description

The invention relates to electrical engineering and can be used to generate the output voltage of a cyclo-converter with rectangular modulation without subharmonic components.

You are a known oscillators ⁵ Khodnev voltage 11].

When the output frequency of the cycloconverter is smoothly set due to the incomplete control of the thyristors, the driving generators ¹⁰ generate output voltages with subharmonic components, which impair the technical and economic performance of the frequency electric drive. *

The closest in technical essence to the proposed one is a master frequency generator of the output voltage of the cyclo-converters, containing a series-connected generator, including a shaper of pulses synchronized with the network and an hour multiplier. notes, frequency divider, and also set—. frequency pickup L21.

A disadvantage of the device is its complexity, since the number of frequency dividers and multipliers depends on the number of selected output voltage frequencies, and the dividers themselves have different division factors.

The purpose of the invention is to simplify the device.

This goal is achieved by the fact that in a single-channel master frequency generator of the output voltage of the cycloconverter, the frequency divider is made controllable, and the frequency control unit is connected to the control inputs of the frequency divider.

In FIG. 1 is a block diagram of a master oscillator, in FIG. 2 - time diagrams illustrating the operation of one phase of a three-phase-three-phase hicloconverter A single-channel master oscillator of the output voltage of the cycloconverter consists of a series-connected generator 1, including a driver 2 synchronized with the & 200A1 network of pulses and a frequency multiplier 3, and a frequency divider 4, to the control inputs of which a frequency adjuster 5, including a driver of the control signal β and an encoder 7, an annular conversion circuit (KPS) 8 is connected to the output of the frequency divider 4.

At the input of the frequency multiplier 3, from the output of the former 2, a pulse is synchronized with the network frequency Λ, ¹ frequency s ίο, connected with the network frequency as ίο “where K is the conversion ratio.

Frequency multiplier 3 has a constant multiplication factor Kc equal to

To. Rg ^Λ m

where tg

- 2.mi _ Zmtm, '-A ^ft ' ^K '

- the number of cycles of rectification of the valve group niklokonvertor;

- phase of the output of the KPS 8, '2m2mf> ~ pulse frequency of the generator 1.

The pulses from the output of the generator 1 with a frequency of £ g are fed to the input of a controlled frequency divider 4, the division coefficient Kd of which is equal to

Κ ^. = 2ν * γπ-2, where N = 1,2, 3, ... is the number of sections of the sinusoid of the supply voltage in the half-period of the output voltage.

The division coefficient K ^ of the divider 4 is set by the encoder 7 of the frequency adjuster 5, the code of which is, in turn, determined by the control signal of the shaper 6. Thus, pulses with a frequency fjr equal to P - fc - 2rox, ^ty 'Kd - GY ^{4 are} formed at the output of the master oscillator the output frequency of the cycloconverter is defined as g m _w ¹ 2N * m-2L 2m ₂

The principle of operation of a single-channel master oscillator is explained in conjunction with the diagrams (Fig. 2) using an example of the operation of one phase of a three-phase three-phase cycloconverter with m = 3.0 ^ = 3, £ l = 5OTc _{> 50} k = 6, N = 3, formed from a three-phase 'the network voltage (Fig. 2a) and pulses synchronized with it with a frequency of £ ₀ = K £ l = = 6.50 = 300 GN of the shaper 2 (Fig / 2b) are fed into the output of the frequency multiplier

IS with a multiplication factor

K ^ = -..... = 3. The pulses obtained after the multiplier 3 with the frequency _λ £ _r «ή ,. = 300.3 = 900 Gi (Fig. 2c) are fed to the input of the divider 4, the division coefficient of which is determined by the value Κγ = 2Ν-Ηπ — 2 = 2.3 + 3-2 = 7. At the output of the deputies 4 pulses with a frequency of £ * g equal to 900/7 are obtained (Fig. 2d). The formation of a three-phase output voltage is performed using the KPS 8 /, the input of which receives pulses of frequency. The control signals of the KPS are logical units entering the control circuit of the thyristors of the cycloconverter (Fig. 2e). The positive half-waves of the three-phase output voltage Ui are formed by signals A, B, C, and the negative half-waves are A, B, C. FIG. 2e shows the output voltage of the Consolidated phase formed from the input voltage U with the help of signal A and A. In accordance with the task, the number of sinusoid parts in each half-cycle is N = 3.

Thus, due to the implementation of the frequency divider 4 controlled from the frequency setter 5, the circuit of the single-channel driving frequency generator of the output voltage of the cycloconverter is simplified by reducing the number of multipliers and frequency dividers.

Claims (2)

The invention relates to electrical engineering and can be used to form the output voltage of a cycloconverter with rectangular modulation without subharmonic components. 11the master oscillators of the output voltage OLl are known. With a gradual setting of the output frequency of the cycloconverter, because of the incomplete control of the thyristors, the master oscillators generate output voltages with subharmonic components that degrade; technical and economic indicators of the frequency electric drive. Most boldly: § by technical nature of the proposed is a master oscillator of an output voltage of a cycloconverter containing a series-connected oscillator, including a driver synchronized with a network of pulses and a multiplier, a frequency divider, and also a frequency reference. The disadvantage of the device is its complexity, since the number of dividers and frequency multipliers depends on the number of selected output voltage frequencies, and the dividers themselves have different division factors. The purpose of the invention is to simplify the device. The goal is achieved by the fact that in the single-channel master oscillator of the output voltage of the cyclo-inverter, the frequency healer is controllable, and the frequency master is connected to the control inputs of the frequency divider. FIG. 1 shows a block diagram of a master oscillator, FIG. 2 - temporary & diagrams illustrating the operation of a single phase of a three-phase-three-phase junction box. The single-channel master oscillator of the output voltage of the cycloconverter consists of successively connected oscillator I, including the driver 2 synchronized with the 3D network of gates and frequency multiplier and frequency divider 4, to the control inputs of which the frequency generator 5 is connected, which includes the § section generator control coder and encoder 7, the output of the frequency divider 4 is connected to the rings conversion circuit (CPS) 8. The input of the frequency multiplier 3 from the output of the fsritovatel 2 receives synchronized with the network frequency fn m pulses of frequency f associated with network frequency as fo K.fi) where K is the conversion ratio. Frequency multiplier 3 has a constant multiplication factor Ki equal to t PC -Q-Tyzi -2.wi.vr I -f number of rectifying cycles of the valve group of the cyclo-converter; nrij is the phasing of the output of the CPS 8, r2t2. - the frequency of the pulse generator 1; Pulses from the output of generator 1, frequency fr, are fed to the input of the control of frequency divider 4, the ratio of which KQ is equal to Kc. "2N4-m-2, where N 1,2, 3, ... is the number of sinusoidal sections of the supply voltage in luperiodu output voltage. Division ratio the divider 4 is set by the encoder 7 of the frequency adjuster 5, whose code in the FAILURE queue is determined by the control signal Vu of the driver 6. Thus, the output of the driver (the Generator generates pulses with a frequency fjp equal to - r - Irni. rnf Kg gy-fgh-g The output frequency 2 of the cycloconverter is defined as (. 2NvifVi-i 2mi. The principle of operation of the single-channel master oscillator is explained together with the diagrams (Fig. 2.) using the example of one phase of a three-phase-three-phase cycloconverter with: & N, Sf fffovannye ie three-phase n rv yvk network (f d. 2a) and sysu- niziruyvaya pulses with a frequency of 6 h. Hz forformer 2 (Fig. 2 receive the Yulkho multiplier of frequency 4 3 with multiplication factor. 3. Lopuchenny 4 4 1 after the multiplier. 3 pulses of frequency fp к., 300. Гп (. 2c) are fed to the input of the divider 4, the division factor of which is determined by the value K? | 2N-Hn-2 2.3 + 3-2 7. At the output of divider 4, the pulses are obtained with a frequency f-ir equal to 900/7 (Fig. 2d) . The formation of a three-phase output voltage is made with a PS ling | KPS 8, at the input of which they are supplied; pulse frequency The control signals of the MCC are the logical units supplied by the cycloconverter thyristor control circuit (Fig. 2e). The positive half-waves of the three-phase output voltage are formed by the signals A, B, C, and the negative signals A, B, C. In FIG. Figure 2e shows the displacement from the input voltage U using a signal A and A, the output voltage of the Ui-phase. In accordance with the task, the number of frequency sinusoids in each half period N 3. Thus, by performing frequency dividers 4 controlled by frequency master 5, the single-channel master oscillator generator of the output voltage of the inverter is simplified by reducing the number of multipliers and frequency dividers. Inventive formula A single-channel master oscillator of an output voltage of a cyclokoid generator containing a series-connected oscillator, including a driver synchronized with a network of pulses and a frequency multiplier, a frequency divider, and a frequency detector, characterized in that, for the purpose of disruption, the frequency divider is controlled, .a frequency master is connected to the control inputs of a frequency divider. Sources of information taken into account during the examination 1.Firago B.I., Gotovsky B.S., Lice Z.A. TSL) history cycloconverters. Minsk, Science and technology, 1973. 2.Zhemerov G. G. Thyristor frequency converters with direct communication. M ,, Energie, 1977., p. 236238. / fn.l ig.2