SU777793A1 - Power-diode converter control method - Google Patents

Description

FIG. 1 shows a power converter circuit; in fig. 2 - temporary diaphragms. .

Parametric current source 1 is connected with valve sets 2, the first is 3-8, the second is 9-14 (for definiteness, a three-phase bridge is shown), valve kits are connected to the load 15.

Diagram 16 (Fig. 2) shows the output currents of a parametric current source, and diagrams 17, 18, and 19 show zero-pause, reverse pulses, and the output current of the converter during a pause with a current setting reverse. In diagrams 20, 21 and 22, the same values without reverse current after a pause. Diagrams 19 and 22 show the numbers of the current-conducting valves.

Consider the principle of current formation.

The reverse and zero pause pulses are synchronized with clock pulses; therefore, the change in circuit states occurs only at zero values of the parametric source current (moments ti, tz, t in the diagrams, Fig. 2). This ensures the optimal course of transients in source 1, thereby reducing the installed power of the power equipment.

When working in each cycle, the next valve of one of the sets is turned on: 3-4-5-6 - with a positive current direction, 9-10-11 -12 - with a negative current in the load, while a smooth current reversal is possible (zero pause pulse duration is equal to zero), for example, when pulses are applied in the following sequence: 3-4-5- 12-13-14-9, etc. The duration of the control pulse is limited to 60 el. degrees, the time of conduction of each valve reaches 180 e. hail.

When forming a zero pause of the current in the load with simultaneous reversal of its direction at moment 5, a zero pause pulse appears (17) and changes its value of the reverse pulse (18), the control pulse passes to the second set valves: at moment 5 the valve 12 turns on instead of valve 6, and the current drops to zero. In the interval, a control pulse is applied to the next valve 13 and at the same time to the valve 6 of another set. Source 1 is shorted with two circuits: valves 5-12, valves 6-13. Moreover, the current gradually moves from valve 12 to valve 6.

In the interval, valves 7 and 14 are turned on, valve 13 has a current dropping to zero. Upon termination of the zero-pause pulse, the formation of additional control pulses is stopped and the current in the load quickly increases to a negative value (Figure 19). The advantage of such a formation, which ensures its pulse WID, is the ease of switching and, therefore, the simplicity of the circuit realization of the control device.

If the load requires a pause in the current without reversal, then during the first two cycles of the pause, the switching order changes. In the interval U-t, valve 12 is turned on (in accordance with the value of the reverse pulse, valve 6 was supposed to work), the current drops to zero. The next vent 7 is then turned on, but no additional control pulse is generated (interval / 6-f). Starting with the next beat,

Both the main control pulses are applied to the valves of the first set, and additional to the valves of the second set, while the source 1 is short-circuited by two circuits. After the cessation of the supply of additional pulses, the current rapidly increases to the former positive value (chart 22). In this way, it is possible to regulate the current in a latitudinal way, and the pause is regulated at minimum sampling intervals equal to an electric pulse 60. hail. The regulation is simply realized with single-pulse,

characteristic of the power of technological installations.

The proposed method allows preserving such advantages of current-parameter converters as the current character of the external characteristic, favorable effect on the supply network, resistance to short-circuits. At the same time, the implementation of the method provides increased reliability and speed.

Claims (1)

Invention Formula A method of controlling a reversible valve converter containing two oppositely-connected valve sets connected to the mains through a parametric current source, which consists in fixing the transition points of the phase currents of the parametric source through zero, and in these moments forming control pulses, is supplied in a cyclical in the order of natural unlocking, control pulses on the first set valves and form zero pause and reverse pulses, characterized in that, in order to increase the reliability time and speed, synchronize the beginnings and ends of the zero-pause pulses and, reverse, change the value of the reverse impulse at the moment of the beginning of the impulse zero pause, and during the zero pause (except for the first cycle) additional control pulses are generated at the valves of the second valve set with a phase shift relative to the natural unlocking moments for one cycle.