SU1504760A1 - Device for controlling rectifier converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used to control valve converters. The aim of the invention is to improve the energy performance. The device contains a pulsed-phase control unit 1, a control angle limiting unit 2, a control range forming unit 3, logic block channels 4-6, each of which contains an RS flip-flop 7 and elements of AND-HE 8, 9. The channels of the logic block are connected to the amplifiers of the formers 10-15, which are connected to the source 18 of the control signal, comprising the element 19, the delay element 20, the element AND-21, the element 22 and the protection signal generating unit 23. In addition, the device is equipped with series-connected differentiating unit 25 and the shaper 24 pulse duration. 2 Il.

Description

SP

about

four

ABOUT

Fig. /

3 1504760

The invention relates to electrical engineering, in particular, to converter technology, and can be used to control valve converters.

The aim of the invention is to increase the energy performance.

FIG. 1 shows a functional diagram of the device for control-tO or a valve converter; in fig. 2 - time diagrams of his work.

A device for controlling the valve. The third inputs of the driver amplifiers 10-15 are connected to the outputs of the logic unit, the signal on which directs the signal at their first inputs by 60, for example, the third input of the amplifier shaper 10 is connected to the first input of the driver of the driver 13, i.e. with channel 5 code.

FIG. 2 shows the time diagrams of the device, where I l.t ll, 2 - output signals of the unit;

and,.

2-1

and

gd

- block output signals

2i Uj ,,, и 3-2 output signal converter contains a block 1 15 block 3; U. ,, U j - output sigpulse-Lazy control, block 2 limits the maximum control angle, block 3 forming the control range, channels 4 -6 of the logic block, each of which is performed on the RS-trigger 7 and two elements IS-HE 8 and 9 (in the drawing, the structure of channel 4 is shown, channels 5, 6 are made similarly), amplifiers 10-15, each of which is identical in the form of series-connected element I-KE 16 and amplifier 17. The control signal source 18 consists of sequentially United First Inverting Ele HEn 19, delay element 20, AND-NOT element 21, the second element NOT 22; the second and third inputs of the element 21 are connected respectively to the output of the protection signal generating unit 23 and the output of the element 19. The input of the element 19 is the input of the source 18 and is connected to the third input of the element 16, the inputs of the shaping amplifiers 10-15 and the output of the pulse width former 24 which the input is connected to the output of the differentiating unit 25.

I differentiating unit 25 with my own

inputs connected to the outputs of channels 4-6.

The output of the first element 8 in channels 4-6 is connected to one of the S-input of trigger 7, the output of the second element 9 is connected to one of the R-BXOs of trigger 7. In this case, the outputs of trigger 7 are outputs of channels 4-6 and connected to the first inputs of the amplifier-shapers 10-15

The inputs of the elements b and 9 are connected respectively with blocks 1 and 3 and with the source 18.

The third inputs of the amplifier-shaper 10-15 are connected to the outputs of the logic unit, the signal on which is ahead of the signal at their first inputs by 60, for example, the third input of the amplifier-shaper 10 is connected to the first input of the amplifier of the imager 13, i.e. with channel 5 code.

FIG. 2 shows the timing diagram of the device, where I l.t ll, 2 - output signals of the block;

and

gd

- block output signals

0

five

0

channel 4 rolls; - output signal of source 18; ,, U - output signals of amplifier-shaper 10 and 11; 124 output signal shaper 24.

The device works as follows.

Unit 1 generates, at its outputs, the signals for setting the angle of control of the thyristors above the target. At that, the front of change of the signal U, sets the moment (phase) of switching on the thyristor of the anode group of the rectifier, and the front of changing the signal U., - the moment (phase) of turning on the thyristor of the cathode group of the rectifier (Fig.2). Block 2 generates signals U. and U at its outputs. in the form of zero level pulses. Signals

and

2-1

and aracterized by the fact that

their decay coincides with the phase of the maximum angle of regulation of the height of the target (and, 1 - for the thyristor of the anode group; - for the thyristor of the cathode group), by the decline of the output signals

 block 2 in the absence of single signals at the output of the block, trigger 7 is forcibly switched at times corresponding to the maximum angle of adjustment. At the same time, control pulses are generated at the output of the amplifier-former 10 or 11 with the maximum angle of control of the rectifier. Unit 3 defines the zones of change of the control angles, at the same time the level Log.1 of the signals Uj., And and correspond to the allowed zones of change of the control angles of the thyristors of the anodic and cathodic groups, respectively. Source 18 forms

at its output, a signal for forcing the thyristors control angle to be set equal to the maximum value of the control angle; the zero level of the signal corresponds to the setting

five .

control angle equal to the maximum value.

The 9th inputs of elements 8 and 9 of channel 4 receive output signatures of block 1, block 3 and source 18. When there are single signals at the inputs of elements 8 and 9, zero pulses are generated at their outputs, tilting trigger 7. The trigger 7 can also be driven by signals Uj ,, Uj from the outputs of block 2. Signals and are generated at the outputs of trigger 7. and and. The angles that control the thyristors of phase A. Channels 5 and 6 operate in a similar way. At the output of channel 5, the signals for setting the angle of control of the phase B thyristors are formed, and at the output of channel 6, the signals for the thyristors of phase C are higher.

The phase shift of the thyristor control angles for phases B and C relative to phase A is 120 and 240 el. hail, respectively.

At the moments of changing the signals at the outputs of the channels 4-6, the differentiating unit 25 generates narrow pulses arriving at the input of the former 24. Shaper 24 generates controllable normalized impulses arriving at the inputs of the elements 16 of the shaping amplifiers 10-15. Signals from other outputs of the logic unit are fed to the other inputs of the elements of the amplifier 16. With the help of amplifier 17, the output signals of the element 16 are amplified and are potentially separated from the circuitry of the device.

I

With proper operation

the devices at the output of the shaping amplifier 10-15 are paired pulses of thyristor control of the converter. The front of the first of two control pulses (, and) is set by block 1, the range of change of the phase angle of the specified first pulse is set by block 3, and the maximum value of the control angle of block 2. The presence of the second of control pulses (lagging 60 alt. Relative to the first) ensures the functioning of the device in the mode of best current due to the simultaneous supply of pulses to the thyristors of adjacent phases of the converter.

04760

Shaper 24 sets the duration-. the output pulses of the device are the minimum value at which

The thyristors of the converter are stably turned on (i.e., during the specified pulse duration, the current increases through the thyristor up to

0 amplitude greater than the thyristor holding current). By controlling the ventilator 1 transducer with paired time-sensitive narrow pulses, the power consumption of the electric power by the shaping amplifiers 10–15 is reduced, which means the energy performance of the device is improved.

When entering the inputs of elements

20 8 and 9 channels 4-6 of the zero-level signal from the output of source 18 (for example, in an emergency situation is a converter - presence of an emergency current through the thyristors) high level signals are generated at the output of elements 8 and 9. Switching thyristors 7 channels 4-6 is carried out output signals; block 2 at the moments of decay of the output signals of this block. With

By this, coupled control pulses are formed at the outputs of the shaping amplifiers 10-15 with the maximum value of the phase of the control angle, as a result of which the EMF is reduced, which ensures the closure of the rectifier thyristors (current flow stops).

Source 18 works as follows

Q way.

The input element J9 from the output of the shaper 24 receives pulses The inputs of the logic element 21 receives signals from the code of the node 23,

, the output signal of the element J9 and the signal from the code of the element 20. In normal operation, the output signal of the node is equal to J. At the output, the element 2J produces pulses, inverse

The output signals of element 21 are lagging behind the corresponding front of the signal of driver 24 by 20-30 μs. Element 21 Signal Inverted

element 22 (the output signal U of the source 18 of the control signal /, is fed to the inputs of the elements 8 and 9 of channels 4-6, blocking the trigger switch 7 for the duration of the control pulse and for 20-30 µs after it.

Blocking the switching of the trigger 7 for the duration of the control pulse serves to prevent spurious switching of the triggers 7 in other channels of the device from the effects of electromagnetic interference signals in the output signal of unit 1. This ensures high noise immunity of the device and ensures reliable formation of paired control pulses at the device output when single-channel principle of the formation of these pulses.

In an emergency situation, a signal 0 is generated in the converter at node 23, which results in a zero signal at the output of source 18, and the output pulses of the device are formed with the maximum value of the control angle.

Thus, the device controls the valve converter with pulses of normalized minimum duration necessary for stable operation of the converter in the modes of continuous and intermittent currents and in emergency modes.

Claims (1)

Improvement of energy indices is achieved by controlling the transducer with narrow pulses of normalized minimum duration, which eliminates additional electrical losses for useless energy consumption of the amplifier by the builders during the time intervals when the presence of pulses on the thyristors is not required rectifier circuits in the current mode.) The invention formula A device for controlling a valve converter containing a multiphase pulse-phase control unit, a maximum control angle limiting unit, a control range shaping unit, a three-logic unit containing an RS flip-flop in each channel and the first NAND element whose first input is connected to the corresponding odd output of the multiphase pulse phase control unit, the second input to the corresponding odd output of the control range forming unit, the third input 50 5 o 0 five to the output of the control signal source, the output of the first element IS-NOT is connected to the first S-input of the RS flip-flop, the second S-input of which is connected to the corresponding odd output of the maximum control angle limiting block, each output of each RS-flip-flop of the logic block is connected with the first input of the corresponding amplifier-former, the outputs of the amplifier-formers are outputs of the device, characterized in that, in order to improve the energy performance, it is equipped with a differentiating unit and a driver for pulses, and each channel of the logic unit is equipped with a second AND-NOT element. Each amplifier-shaper is equipped with an input element AND, the inputs of which are the inputs of the amplifier-shaper, the control voltage source is in the form of two elements NOT, a delay element, an element NAND and the node of the formation of the protection signal, whereby the outputs of all RS-flip-flops are connected to the second inputs of the amplifiers-drivers and the input of the source of the control signal through the differentiating unit and the pulse width former the control signal input is the input of the first element NOT, the output of which is connected to the first input of the NAND element and through the delay element to the second input of the NAND element, the third input of which is connected to the output of the protection signal generating unit through the second element is NOT connected to the outputs of the source of the control signal, in each channel of the logic block the output of the second element is NOT connected to the first R input of the RS flip-flop, the second The R-input of which is connected to the corresponding even-numbered input of the limiting maximum control angle, the first and second inputs of the second NAND element are connected to the corresponding even outputs of the multiphase pulsed-phase control unit and the control shaping unit, the third input to the output of the control signal source and the third input of each amplifier of the driver is connected to the output of the channel of the logic unit, the signal on which is ahead of the signal at the first input by 60. /./ 1-2 f.l gj j-f  t Jl i R i u -i  Nppppppppppg f n P PP u, ten V: 24 П n n П П 0 fl П П П в П П eleven Jl 0 FIG. 2