SU1180863A1 - Method of extremum controlling of electrostatic precipitator voltage - Google Patents

Abstract

THE METHOD OF EXTREME REGULATION OF ELECTROFILTER VOLTAGE, based on a periodic stepwise change of the control signal, determining the sign of the voltage increment, comparing it with the sign of the control signal increment, increasing the latter when the signs coincide and decreasing when they differ, different from that, in order to increase the average value of the voltage in the presence of a return corona in the electrostatic precipitator, the step of reducing the control signal is chosen greater than the step of increasing it, and after each decrease of the control signal is increased and then the sign of the voltage increment is determined.

Description

1 The invention relates to electrical engineering and is intended for use in the construction of electrical supply systems for gas cleaning devices. The aim of the invention is to increase the average voltage value in the presence of an inverse corona in the electrostatic precipitator. FIG. 1 shows a functional diagram of a device implementing the proposed method for the extreme control of the voltages of the electrostatic filter J in FIG. 2 - current-voltage characteristics of the electrostatic precipitator (one of which corresponds to a decrease in current, and the other to its increase), High-voltage rectifier 1 is connected to the input of transformer 2, the primary winding of which is connected to the network through a triac element 3 equipped with a control unit 4. To output of rectifier 1 Electrostatic precipitator 5 and voltage divider 6 are connected. The output of the latter is connected to the input of the block 7 in the derivation of the derivative (differentiation). Block 7 has two outputs - positive to negative increments of the control signal. The output of the block can be positive and negative. The polarities of the output signals are separated by diodes 8 and 9. Due to the fact that the device uses positive logic, the output of diode 8 is connected to an inverter composed of resistors 10 and 11 and a power amplifier 12. The device includes elements AND 13-16, elements OR 17-19, shapers 20 and 21 pulses5 block 22 delay trigger 23, an integrator composed of resistors 24 and 25, capacitors 26 and 27 and a power amplifier 28, low-frequency generator 29 and current sensor 30 . Elements And 13 and 14 fix the presence of an arbitrary negative polarity, and the elements 15 and 16 - of positive polarity. The outputs of the elements And 14 and 15 are connected to the inputs of the element OR 17, and the outputs of the elements And 13 and 16 - with the inputs of the element OR 18. The output of the element ШТЙ 17 is connected to one of the inputs of the element OR 19, 632 The outputs of the elements OR 19 and 18 are connected to the inputs respectively, the shaper 20 and 21 pulses, the outputs of which, in turn, are connected to the inputs of the integrator (to the resistors 25 and 24). The output of the imaging unit 21 is also connected through a delay unit 22 to another input of an ISh element {19. The inputs of the trigger 23 are connected to the outputs of the OR elements 17 and 18, and the outputs to the corresponding inputs of the latter and, in addition, one of the inputs of the elements I. And 13- 16, the other inputs of which are connected to the output of the generator 29. The output of the integrator (operational amplifier 28) is connected to the first input of the control unit 4, and the output of the current sensor 30 to its second input. The output of the control unit 4 is connected to the control input of the regulating element 3. The method is carried out as follows. The voltage on the transformer 2 is adjusted by the triac 3 by changing the phase of the pulses of the control unit 4. At the same time, the output voltage of the rectifier 1, applied to the electrostatic precipitator 5, changes. This voltage through the divider 6, reducing its value, is supplied to the derivative extraction unit 7. Differentiation in the block is performed with anti-aliasing. With an increase in voltage, there is a positive signal at the output of diode 9, and with a decrease, a negative signal at the output of diode 8, converted by an inverter (elements 10-12) into a positive one. Derivatives from the output of block 7 are fed to the inputs of the AND 13-16 elements and further to the inputs of the OR elements 17 and 18, where they are logically multiplied by the increment sign of the control signal at the preceding point in time. The specified signal comes from the outputs of the trigger 23. When the signs of the increments of the control signal and for example - coincide. The marriage on the electrostatic precipitator 5, the element OR 17, starts up the shaper 20, which generates a control signal of constant duration, which is fed to the direct input of the integral (resistor 25). The integrator increases the control signal from block 4 to a certain constant level, which leads to an increase in the output voltage of the rectifier 1. Simultaneously with the start of the imaging unit 20, a signal is applied to the trigger 23, which fixes the positive increment of the control signal. The generator 30 periodically (every few seconds) provides the inputs of the elements And 13 and 14, the signal for the implementation of the next step. The first step when switching the device into operation is carried out in the direction of increasing the voltage due to the fact that the initial angle of the triac 3 is established by the control unit 4 less than 180 el. hail. If the signs of the increments of the control signal and the output voltage do not match, the shaper 21 is triggered, providing a signal longer than the shaper 20. Therefore, the step of reducing the voltage is greater than the step of increasing. After working off this stage with a delay of 1808634

By the unit 22, the shaper 20 is started, causing a voltage boosting step. The result of this cycle occurs. 5 the resulting decrease in the control signal.

From FIG. 2 that the current-voltage characteristics of the 31 and 32 electrostatic precipitators 5 have a hysteresis inlet (due to the effect of the reverse corona). If you move from point 33 to the current, the phase path will come to point 34. If you increase the step size, as is the case with the proposed method, the phase path ends at point 35, but then at the final stage increases the signal will lead to point 36, which corresponds to a higher average voltage value on the electrostatic precipitator 5 than at point 34.

25 Increasing the average value of the voltage determines better gas cleaning.

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Claims (1)

METHOD FOR EXTREME VOLTAGE REGULATION OF THE ELECTRIC FILTER, based on the periodic '' stepwise change of the control of the voltage increment, its comparison with the sign of the increment of the control signal, increasing the latter when the signs coincide and decreasing when they do not coincide, characterized in that, in order to increase the average voltage value if there is a reverse corona in the electrostatic precipitator, the step of decreasing the control signal is chosen greater than the step of increasing it, and after each reduction of the control s Nala perform its magnification and then only determine the sign of the increment voltage