SU440283A1 - Device for switching static converter stages - Google Patents

Description

one

The invention relates to devices for controlling bridge-and single-phase single-phase current converters with smooth, non-contact phase-zone control of rectified and inverted voltages, and can be used in electric drives with multi-stage control of the load voltage, mainly in electrical voltage.

A device for switching the crypoins of a multi-bridge static converter is known, comprising phase-shifting elements, a phase distributor of phase-shifting elements, reference pulse shapers, a switching angle meter, an inverter extinction angle control unit, logic elements matching, prohibiting and time delays and triggers.

In the known device, control actions (commands) on the transition from stage to stage are carried out with the help of null-bodies, which react to a certain amount of control voltage. The opening angle of the converter valves is also proportional to the control voltage, and the full development of the phase-controlled stage corresponds to a certain control voltage. However, due to the drift of null-organs, the same commands for the transition from stage to stage. stage formed at different

control voltage, therefore, the transition from stage to stage is carried out earlier or later than the true output of the phase-controlled stage. This leads to the formation of an unregulated zone in the event that the null organ is triggered with a larger control voltage. Thus, there is no exact correspondence between the moment of true generation of the phase-controlled stage and the moment of operation of the null organ.

The purpose of the invention is to improve the energy performance, to ensure the smoothness of the converter control process during the transition from stage to stage and to simplify the work in the inversion mode, as well as to obtain accurate information about the true generation time of the phase controlled stage and about the moment of transition from this control stage to another.

The proposed device differs from the known new functional relationships between the blocks. The output of the phase-shifting element of the first stage of the converter and one of the outputs of the trigger with a counting start are connected to the inputs of two coincidence elements, the output of the switching angle meter is connected to the third input of one of them, and its output is connected via a time delay element to the trigger input

separate start, the output of the other coincidence element is connected to the input of the pulse distributor of the phase-shifting elements and to the second input of this trigger, the output of which and the output of the phase-shifting element of the second stage of the converter are connected to the inputs of the two other elements of the coincidence, the third output of one of them is connected to the second trigger output with a counting start, and its output is connected to the input of the pulse distributor of the phase-shifting elements and to one of the inputs of the prohibition element, the output of which is connected to one of the one other trigger with separate start, the output of which and the output of the reference pulse generator at the end of the half-cycle are connected to the third and fourth inputs of the second of the indicated coincidence elements, the output of which is connected to both trigger inputs with a counting start and the second input of another trigger with separate start, and the second input of the prohibition element is connected to the output of the driver reference pulses at the end of the half period.

The device is equipped with an operation mode switch connected between the coincidence and inhibit elements and the driver of the reference pulses and the control unit for the extinction angle of the inverter. In order to obtain information on the development of a phase-controlled converter stage and the moment of transition from one control stage to the next, the device is equipped with an indicator connected to one of the trigger outputs with a counting start.

The connection of logic elements between each other and with the converter control device provides, without using null-organs, switching the converter from the previous adjustable stage to the next one after the full, true development of the phase of its previous stage.

The drawing shows a block diagram of the proposed device.

The output of the phase-shifting element 1 of the first stage of the converter and one of the outputs of the trigger 2 with the counting start are connected to the inputs of two logic elements 3 and 4. The output of the angle meter 5 is connected to the third input of the match element 3 when the converter is running in the rectifier mode or the output of the driver 6 reference pulses at the beginning of the half-period when it is working in the inversion mode. The switching of the operating modes of the converter is performed by the switch 7 of the operating mode. The output of the coincidence element 3 through the element of time delay 8 is connected to one of the inputs of the trigger 9 with separate start, the output of the logic element 4 is connected to the second input of which and to the input of the pulse distributor 10 phase-shifting elements 4. Output of the phase-shifter pulse distributor through the unit

the amplifiers 11 are connected to the control circuits of the G1 converter 12. The output of the trigger 9 with separate start and the output of the phase-shifting element 13 of the second stage of the converter are connected to the inputs of two matching elements 14 and 15. A second output of the trigger 2 with the counting start is connected to the third input of the matching element 15. The output of the coincidence element 15 is connected to the input of the pulse distributor 10 phase-shifting elements and to one of the inputs of the inhibit element 16, to the second input of which and to the third input of the coincidence element 14 through the operation mode switch 7, the output of the reference 17 pulse former 17 is connected when the converter is in straightening mode or the output of the inverter's stock 18 angle control unit when the converter is in inverted mode. The output of the prohibition 16

 connected to one of the inputs of the trigger 19 with separate start, the output of which is connected to the fourth input of the logic element 14. The output of the match element 14 is connected to both inputs of the trigger 2 with the counting start and to the second input of the trigger 19 with separate start. In the drawing, the position of the switch 7 corresponds to the operation of the converter in the rectifier mode.

 The device works as follows.

In the initial state from one of the outputs

trigger 2 with counting start is removed

input enable signal

two elements of coincidence 3 and 4, and the prohibitory signal removed from the other output of this trigger goes to one of the outputs of the coincidence element 15. At the same time, the signal from the output of the phase-shifting element 1, passed through the open element of coincidence

4, the pulse distributor 10 of the phase-shifting elements and the amplifier unit 11 enters the first stage of the static converter 12, adjusting the valve opening phase in the arms of this stage. The signal from the output of coincidence element 4 also goes to one of the inputs of trigger 9 with separate start, tilting it to its original state, in which its output removes the inhibitory signal to the inputs of two elements of the coincidence signal from the output of phase shifting element 13 of the second stage of the converter.

After the phase-controlled first stage of the converter is fully developed, determined by the moment of coincidence of the signal from the output of the phase-shifting element 1 with the falling edge of the signal from the output of the commutator angle meter 5, the output of the element 3 coincides with a signal that is used as a command to go from the first stage of adjustment to the second.

The signal from the output of the coincidence element 3 is fed to the temporary delay element 8, which prevents simultaneous blunting of the signals to both inputs of the flip-flop 9 with a separate start, ensuring its stable operation. The signal from the output of the time delay element 8 overturns the trigger 9 with a separate start to another steady state, in which the output signal for the coincidence elements 14 and 15 is removed from its output. The other inputs of the logic element 14 receive the enable signal from the output of the driver 17 and also the enabling signal from the output of the trigger 19 with separate start and from the output of the phase-shifting element 13 of the second stage of the converter. With the simultaneous presence of all these signals at the inputs of the coincidence element 14, a signal is generated at its output, arriving at trigger 2 with a counting trigger and tilting it to a state in which the inhibitory signal arriving at the inputs of the two elements of coincidence 3 is removed from one of its outputs. and 4, and from the other of its outputs, the permitting signal is fed to one of the inputs of the matching elements 15. The signal from the output of the matching element 14 also goes to one of the inputs of the trigger 19 with separate start, tilting and it is in a steady state, in which there is no signal at its output, which excludes the occurrence of a repeated signal at the output of the coincidence element 14 and, consequently, re-tilting of the trigger 2 with a counting start. This completes the process of direct transition from the first stage of regulation to the second. The trigger 19 with separate start will be in the state tilted by the signal from the output of the coincidence element 14, and no signal will be output at its output until its other input receives a signal from the output of the inhibit element 16. The signal at the output of the inhibit element 16 appears when one of its two input signals is absent (before moving from the first stage of adjustment to the second) or when both signals arrive at its input non-simultaneously, i.e. after the transition to the second stage, when passing through the coincidence element 15 si nal output from the phase shifting element 13 due to the control to change its phase relative to the signal phase with the output of the reference clock 17, which also causes no signal at the output of the element matcher 14, although the input of this element coincidence output from the flip-flop 19 with a split running has the resolving signal arrives. The output signal of the phase-shifting element 13, passing through the open element of the coincidence 15, the pulse distributor 10 of the phase-shifting elements and the amplifier unit I, enters the second stage of the converter 12, adjusting the valve opening phase in the arms of this stage.

Similarly, a direct transition from the second stage of regulation to the third, from the third to the fourth, and so on.

The reverse transition, for example, from the second stage of regulation to the first, was carried out as follows. At the moment when the phase-adjustable signal from the output of the phase-shifting element 13 and the output signal from the driver 17 of the reference pulses, together with the resolution signals from the output of the flip-flops 9 and 19 with the separation start, simultaneously arrive at the inputs of the coincidence element 14, a signal is generated at its output. This signal overturns trigger 2 with a counting start to this state,

in which from one of its outputs a inhibit signal is fed to the input of the coincidence element 15, and from the other output of the signal the enabling signal to the inputs of the elements of coincidence 3 and 4 is taken.

match 3 will be closed due to non-simultaneous arrival of a signal from the output of the commutator angle meter 5 and two other signals to its input, and the match element 4 will be open. The signal from the output of the phase-shifting element 1 through the open element of the co-combination 4, the pulse distributor 10 of the phase-shifting elements, the amplifier unit 11 goes to the first stage of the converter 12. The same signal from the output of the coincidence element 4 tilts the trigger 9 with a separate start its output is removed prohibitory signal to the inputs of the elements of the match 14 and 15. It stops the signal from the output

phase-shifting element 13 through a matching element 15 to the second stage of the converter 12 and through a matching element 14 to the inputs of the trigger 2 with the counting start and the trigger 19 with separate starting. This completes the reverse transition process.

Switching the converter control steps in the inverting mode is the same as in the rectifying mode, but instead of the output of the commutator angle meter 5, the output of the reference pulse generator at the beginning of the half-period of the supply voltage converter is connected to the input of the coincidence element 3, and instead of the output pulse generator 17 of the reference pulse at

the end of the half period to the inputs of the prohibition element 16 and the coincidence element 14 is connected to the output of the inverter’s stock angle control unit 18. Thanks to the connection of the sensitive

the indicator to one of the outputs of trigger 2 with a counting start, you can visually monitor the transition from one adjustable step converter to another.

Subject invention

Claims (3)

1. Device for switching steps single phase static converter current with smooth contactless phase-zone regulation of rectified voltage containing phase-shifting elements, phase-shifting pulse distributor, reference pulse shapers, commutation angle meter, inverter extinction angle control unit, and logical elements of coincidence, prohibition and time delay and triggers, in order to improve the energy performance of the converter and ensure smooth process control, the output of the phase-shifting element of the first stage of the converter and one of the outputs of the trigger with a counting start are connected to the inputs d two matching elements, the output of the commutation angle meter is connected to the third input of one of them, and its output is connected through a time delay element to the trigger input with separate start, the output of the other matching element is connected to the input of the pulse distributor of phase-shifting elements and to the second input of this trigger, the output which and the output of the phase-shifting element of the second group of the converter are connected to the inputs of the two other elements of coincidence, the second trigger output is connected to the third input of one of them with a counting start, and its output is connected to the input of the distributor of pulses of phase-shifting elements and one of the inputs of the Prohibition Element, the output of which is connected to one of the inputs of another trigger with separate start, the output of which and the output of the driver of the reference impulses at the end of the period are connected to the third and fourth the inputs of the second of the indicated elements of coincidence, the output of which is connected to both inputs of the trigger with a counting start and with the second input of another trigger with separate start, and the second input of the blocking element and is connected to the output of the reference clock at the end of half cycle. 2. The device according to claim 1, characterized in that, in order to simplify the operation in the inversion mode, it is provided with an operation mode switch connected between the coincidence and prohibition elements and the driver of the reference pulses and the inverter fade control unit. 3. The device according to paragraphs. I and 2, characterized in that, in order to obtain information on the moment of generation of the phase-controlled stage and on the moment of transition from this stage control to another, it is equipped with an indicator connected to one of the trigger outputs with a counting start.