SU1243823A1 - Unit for supplying electric precipitator with alternate voltage - Google Patents

Description

The invention relates to the electrical purification of gases by means of electrofilters, namely, to feeding them with high voltage.

The purpose of the invention is to increase the efficiency, reliability and efficiency of the device when working on any type of electrostatic precipitators.

Figure 1 shows the block diagram of the device; figure 2 - a temporary chart of his work.

The electrostatic precipitator 1 is connected via an anti-parallel-connected electron-beam valves 2 and 3 to the secondary winding of a high-voltage, pulse transformer 4, the primary winding of which is connected to the output of a single-phase autonomous inverter performed on key elements 5–8. The input of the autonomous inverter is connected to a constant voltage source, infused on a three-phase bridge gate 9, connected to a three-phase AC network. A voltage sensor 10 is connected between the electrodes of the filter, and a backward-corona sensor 11 is connected to the precipitating electrode of the filter.

The output of the voltage sensor 10 is connected to the input of the breakdown recorder 12, the output of which is connected to the first input of the inverter key control pulse generator 13, the first input of the OR circuit 14, and the input of the delay circuit 15, the output of which is connected to the second input of the 1SR circuit 14. Reverse sensor 11 output the crown is connected to the second input of the driver of the inverter key control pulses 13, the third input of the OR circuit 14 and the input of the delay circuit 16, the code of which is connected to the fourth input of the OR circuit 14, the output of which is connected to the counting trigger input 17, the outputs of which are connected to the third and fourth inputs of the pulse former 13, control the keys of the inverter .. The output of the reverse corona sensor .11 is also connected to the input of the driver 18 of the control pulses of the switching elements, which is triggered by the 19th, countable the input of which is connected to the output of the sensor 11 of the reverse corona, and the outputs through the amplifiers-formers 20, 21 -.C with the control inputs of the electron-beam gates 2 and 3.

The shaper 13 of the inverter key control pulses is made according to a known scheme and contains a pulse-width modulator 22, the first

the input of which is connected to the output of the recorder sample 12, the second - with the output of the reverse corona sensor 11 to the input of the counting trigger 23, the first input of which is connected to the first

the inputs of the selectors 24 and 25, and - to the first inputs of the selectors 26 and 27. The outputs of the selectors 24 and 26 through the logic circuit OR 28, and the selectors 25, 27 through the logic circuit OR 29

connected to the separate inputs of the trigger 30, the outputs of which are connected to the slave amplifier 31 with the transformer output, and the counting trigger 23 is connected to the master 32 with its outputs

amplifier with transformer output. The amplifiers 31 and 32, in turn, are associated with the corresponding key elements of the .5-8 autonomous inverter, and the transceivers of latitudes of the no-pulse

modulator 22 - with the second inputs of selectors 24-27. The third inputs of the selectors 24, 26 and 25 and 27 are connected to the first and second outputs of the trigger 17, respectively.

The device works as follows.

The shaper 13 of the inverter key control pulses amplifies the pulses of the control of the key elements 5-8 of the autonomous inverter, providing the desired shape of the output voltage curve (U in Fig. 2), its regulation using the pulse width modulation method, and

known scheme. The driver 18 of the control pulses of the switches generates control pulses of the ramization in antiphase by the switches 2 and 3 (and, Uj in FIG. 2),

according to the well-known scheme and provides

the supply of rectangular voltage pulses of a given magnitude to the switching electrodes of the switches. For example, for a switch on a valve type

The EBL 1/150 voltage pulse amplitude of 2-4 kV at a current of up to 300 / i A. The amplifiers-formers 20, 21 included in the former 18 are made according to a known scheme.

55

Let switch 2 be open at the initial moment (C, figure 2), and from the output of high-voltage pulsed trans

3

Former 4 removes pulses that provide the formation of positive polarity voltage on the electrostatic precipitator (Uj in Fig. 2) and are modulated according to the law, which provides a predetermined voltage shape on the electrostatic precipitator (Up in Figure 2) using a second-type PWM. The signal from the inverse corona sensor 11 at time t (Vt, figure 2) starts the switching of the circuit to form a negative polarity voltage. In this case, the voltage pulse U / arrives at the trigger trigger input 19 by turning off the electron-beam valve p including the electron-beam gate. The voltage pulse U. arrives at the inputs of the latitude by the pulse of the modulator 22 and the counting trigger 23, by preparing the driver 13 of the inverter key control pulses to form a negative polarity voltage on the elastic filter STI. In addition, the voltage pulse Ui | through the OR circuit 14, it enters the input of the trigger 17, which switches and changes the phasing of the inverter key control pulses, which leads to the discovery of the key elements 8 and 6 of the inverter. In this case, the primary winding of the transformer 4 is shorted and the electrostatic precipitator speed is quickly discharged through the electron-beam valve 3 and the secondary winding of the transformer 4. And since the key elements 5 and 7 are open, the discharge of the electrostatic precipitator does not affect the power supply network. At time tj (Fig. 2), when the capacity of the electrostatic precipitator discharges to a certain minimum value, for example down to zero, a voltage pulse appears at the output of the delay circuit 16 delayed relative to

pulse voltage u. This impulse

voltage through the OR circuit. 14 is fed to the counting input of the trigger 17, which returns to the initial state, and the phasing of the control pulses of the inverter keys 5 to 8 changes, providing alternate opening

ten

20

. . 30 35 25

0

15

key elements 5, 6 and 7, 8 in accordance with the law of pulse-width modulation. The magnitude of the voltage on the electrostatic precipitator is regulated by the method. home pulse width control frequency of the spark discharge in the electrostatic precipitator. The breakdown signal in the electric filter is detected by the recorder 12 sample and fed to the input of the pulse-width modulator 22 of the driver 13. When the electric filter is broken through, the signal from the output of the recorder 12 sample which is performed on a known circuit also goes through the circuit OR 14 to the trigger input 17 In this case, a process similar to the process occurs when switching the polarity of an alternating voltage. For example, suppose that a breakdown occurred during the formation of a positive polarity on the electrostatic precipitator; The electron-beam valve 2 is turned on. Then at the time of the sample, the phasing of the inverter key control pulses changes, which leads to the opening of key elements 8 and 6, the primary winding of the transformer 4 is short-circuited and the supply voltage to the electrostatic filter is quickly removed. After some time, set by the delay circuit 16 and required to restore the dielectric strength of the electrostatic precipitator, a voltage pulse from the output of the delay circuit 16 through the OR circuit 14 triggers the trigger 17 to its initial state and the voltage recovery process takes place on the electrostatic precipitator.

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Compiled by V.Nagorny Editor A.DolinichTechred L.Oleinik

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Proofreader V. Sinitska.

Order 374Г / 10 Circulation 514. Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5

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Production and printing company, Uzhgorod, st. Project, 4

Claims (1)

VARIABLE VOLTAGE ELECTRIC FILTER DEVICE, containing high voltage rectifier, switching elements,. a pulse shaper for controlling switching elements, a reverse corona sensor and a voltage sensor, characterized in that, in order to increase the efficiency, reliability and efficiency of the device when working with any type of electrostatic precipitator, it is equipped with an additional single-phase autonomous inverter, a pulse shaper of control, a high-voltage 'pulse transformer and the second and first delay circuits, an OR circuit, a trigger and a breakdown recorder, while the output of the autonomous inverter is connected to the primary winding of a high voltage about a pulse transformer, the secondary winding of which is connected to the common input terminal of the first and second switching elements antiparallel, the inverter input is connected to a three-phase network through a rectifier, and the output of the voltage sensor through a breakdown recorder is connected to the first input of the inverter control pulse generator, the first input of the circuit OR and the input of the first delay circuit, the output of which is connected to the second input of the OR circuit, the third input of which is connected to the output of the reverse corona sensor, the second input of the form pulse generator control inverter, the input of the pulse shaper control switches and the input of the second delay circuit, the output of which is connected to the fourth input of the OR circuit. the output of which is connected to the counting input of the trigger, the out-of-phase outputs of which are connected to the third and fourth inputs of the pulse shaper control keys of the inverter. SLL ,,, 1243823 A1