SU754637A1 - Single-channel apparatus for phase control of m-phase static converter - Google Patents

Description

The invention relates to electrical engineering and can be used mainly in phase control systems for T-phase pulse-width converters and controlled by rectifiers on both thyristors and transistors.

A single-channel device is known for controlling a converter, which contains a synchronization unit with a network, two phase-shifting elements and a pulse distributor, in which the extension of the phase control range is achieved by performing a pulse distributor in the form of a semi-controlled rectifier [1].

The disadvantage of this device is a limited control range.

The closest in its technical essence to the present invention is a single channel device for phase control of an m-phase static converter comprising a functional unit comprising fazorasschepitel which generates at the first output of said block T T pulse sequences with a frequency of 1 _{to a} feed CE2

ti, duty cycle a = 2 and phase shift φ = 2 l / t relative to each other, and the node forming sync pulses with repetition rate t1 _s at the second output of the same block, phase shifting unit, input to the _{5th one is} connected to the second output of the functional unit, pulse distributor, the input of which is connected to the output of the phase-shifting device, and m two-input coincidence circuits at the outputs of the pulse distributor, the second inputs of which are connected to the first outputs of the same name

functional block [2].

A disadvantage of the known device is that the phase-shifting unit operates at a frequency t! _c , therefore the regulation angle a cannot be more than 2 l / t; the duration ί of the control pulse is set by the phase-shifting device, is determined by its circuit and generally depends on the magnitude of the control voltage E) _y , but it is not equivalent to the control angle ^ In the case under consideration, the dependence ϊ = = Έ (yy) is not indispensable.

The purpose of the invention is the expansion of the range of phase control while simultaneously754637

Nominal functionality.

This is achieved by those.: That the known single-channel device for phase control of a t-phase static converter is equipped with a frequency multiplier, the frequency multiplier is connected between the pulse distributor and the phase shifter, whose input is connected to one of the phase splitter outputs, the pulse distribution unit made as a phase splitter.

FIG. 1 shows a block diagram of the device; in fig. 2 - diagrams explaining its work (for the case of a three-phase converter).

The device contains the first and second phase splitters 1, 2, predominantly assembled according to an annular scheme, each of which forms at its output t the pulse train with frequency) _{from the} mains, duration ί = 1/2 ( _c and phase shift <p = 2l / t relative to each other, phase shifting unit 3, which includes a generator of 4 linearly varying voltage, for example, a sawtooth voltage generator, and a comparison circuit 5, tons of coincidence elements 6, a driver 7 sync pulses, a frequency multiplier 8 and a generator 9 rectangular imp lsov.

The device works as follows

Generator 9, synchronized with the mains, generates a periodic sequence of rectangular pulses with a frequency G o = pc and a pulse duration ί ₀ = 1 / 2ϊ ₀ (duty cycle a = 2; see Fig. 2a). The first phase splitter 1 forms, at its t outputs from this pulse sequence, the first series of m rectangular pulse sequences with a frequency Г, = Γ ₀ / t = { _e , pulse duration = t / 2 ( ₀ = 1/2 Г _с (duty cycle a = 2), shifted in phase by a fixed angle <p = 2LDP relative to each other (Fig. 26).

One of the w formed pulse sequences (in Fig. 1 - from the t output of the phase splitter) is used to form the second series of m pulse sequences with ί2 = _£ , _{ί 2} =. = 2 l / t, ₂ = 1 / 2ί ₀ (a = 2) and the angle of regulation (x = 0-180 ° el., I.e. with the same parameters as the first series, but shifted relative to it by the angle of regulation a = 0-180 ° el.

The formation of this series is as follows.

The generator 4 is synchronized by the shaper 7, which generates sync pulses with a frequency of 2 { _s (Fig. 2c) · From the output of the generator 4, voltage, for example, of a sawtooth shape, is fed to the comparison circuit 5, where it is sorted with the control voltage C,

At moments of equality of these voltages, when their difference changes sign (point K in Fig. 2d), pulses are generated at the output of the comparison circuit 5 with a repetition rate equal to 2 ( _c and u = 0-180 ° el. Depending on the value of the control voltage and _y (Fig. 2d), which are multiplied in frequency in a multiplier 8, having a multiplication factor equal to m / 2. As a result, a pulse oscillation with a frequency m) _{c is} received at the input of the second phase splitter 2 (fig. 2e), and c m outputs phase splitter 2 are removed T pulse sequences with ί ₂ = G _s , h> 2 = 2 l / t, ί ₂ = 1 / 2GS (a = 2) and c = 0-180 ° el (Fig. 2g).

The control angle a is determined by the magnitude of the control voltage C ,, since the position of point K in FIG. 2g uniquely depends on and _5. As can be seen from FIG. 2d, 2d), with a corresponding change in the magnitude of the control voltage C, the angle * of regulation and varies from 0 to 180 ° el.

The second series formed in this way from the pulse sequences comes from the outputs of the second phase splitter 2 to 5 comparison schemes, where the first series from the outputs of the first phase splitter 1 is also supplied. From the coincidence of the pulses at the outputs of 6 matching elements 6, m sequences of pulses are formed. = Гс, (рз = 2 l / t, а = 0—180 ° el., Ί з = 0 -! / 2 ( _s (Fig. 2h), moreover, a and ί ₃ do not depend on the phase of the transformation.

This single-channel device for phase control of a t-phase static converter expands the range of phase control — increases the control angle a to 180 ° el. and at the same time equivalent to it, the duration of control pulses up to 1/2 (5; regardless of the phase conversion). This new quality of the device allows it to be used for phase control of pulse-width converters, as well as controlled by rectifiers both on transistors and on thyristors.

Claims (2)

Claim 1. Single-channel device for phase control of a t-phase static converter containing a pulse generator connected to a phase splitter, a phase-shifting unit, a pulse distribution unit, a clock generator and t two-input matching elements, the first inputs of which are connected to the outputs of the pulse distribution unit, the second inputs are the same output phase splitter, characterized in that, in order to expand the range of phase control while expanding the functionality, it is equipped with a frequency multiplier, and 754637 five 6 a frequency multiplier is connected between the pulse distributor and the phase shifting block whose input through the driver sync pulses connected to one of phase splitter outputs. 2. Device by π. 1, characterized in that the pulse distribution unit is made in the form of a phase splitter.