CN110355001B

CN110355001B - Quick protection system of electrostatic precipitator

Info

Publication number: CN110355001B
Application number: CN201910720210.0A
Authority: CN
Inventors: 王波; 李时辉; 郑鹏飞; 骆晨岚
Original assignee: Huoshan Zhixing Information Technology Co ltd
Current assignee: Suzhou Xinda Resources Recycling Co ltd
Priority date: 2019-08-06
Filing date: 2019-08-06
Publication date: 2020-11-06
Anticipated expiration: 2039-08-06
Also published as: CN110355001A; CN111420807A; CN111420806A; CN111420807B; CN111420806B

Abstract

An electrostatic precipitator rapid protection system, comprising: the electrostatic dust collector comprises an electrostatic dust collector, a discharge electrode, a dust collecting electrode, a dust cleaning device and a power supply controller, wherein the electrostatic dust collector shell is provided with an air inlet and an air outlet; the method is characterized in that: the power supply controller comprises a rapid protection circuit and a logic control circuit, when the phenomena of back corona, flashover, spark discharge and arc discharge occur, the electrode voltage of the electrostatic dust collector is detected and reduced at the first time, the generation of the phenomena is effectively inhibited, meanwhile, the power output is reduced and the electrodes are cleaned in time by controlling a switching device in the high-voltage power supply through the controller, and the rapid protection and recovery of the electrodes after the electrostatic dust collector is abnormally operated are realized.

Description

Quick protection system of electrostatic precipitator

Technical Field

The invention belongs to the field of electrostatic dust removal devices, and particularly relates to a system for rapidly protecting an electrostatic dust remover in an abnormal working state.

Background

An Electrostatic Precipitator (ESP) is a large-scale industrial dust removal device, and is widely applied to industries such as electric power, cement, steel and the like because of the characteristics of high dust removal efficiency, low energy consumption, capability of treating gas with high temperature and large smoke amount and the like, and becomes a main device for smoke treatment in various industries. The working principle can be summarized that the flue gas is ionized by using a high-voltage electric field, and the dust charges in the air flow are separated from the air flow under the action of the electric field. The electrostatic dust collector is a relatively complex and changeable system, and how to ensure the stable operation of the electrostatic dust collector and timely detect and eliminate the operation fault of the electrostatic dust collector is always an important subject in the field of electrostatic dust collection equipment. In the actual operation of the electrostatic dust collector, some abnormal situations can occur, such as a back corona phenomenon, namely when the electrostatic dust collector operates under high specific resistance dust, the increase of corona current and the thickening of a dust layer and the increase of the accumulated charge quantity of the dust layer cause the increase of the intensity of the back electric field to be larger than that of an original electric field, the dust collecting field intensity is weakened, the driving speed of particles is reduced, and the dust collecting efficiency is reduced. For example, in addition to the normal corona discharge, the electrostatic precipitator may generate spark discharge caused by different reasons, including spark discharge caused by gas breakdown between electrodes, spark discharge caused by breakdown of a high specific resistance dust layer, or spark discharge caused by back corona discharge after breakdown and subsequent spark discharge.

In the prior art, the solution for the above problems is to reduce the working voltage of the electrostatic precipitator when a fault is detected or to clean and troubleshoot the electrode after the electrode is powered off, for example, hitachi company adopts the method that after an abnormal condition is detected, the voltage value output by the power supply is reduced by controlling a switching device in the high-voltage power supply through a controller, so as to reduce the occurrence of the phenomena of back corona and spark. The method that the mechanical relay is directly connected with the high-voltage output end is adopted to control the electrode to supply power in the early American electrostatic dust collector control technology, the method can generate serious arc discharge in the switching process, meanwhile, the power supply is disconnected through the relay after back corona and spark are generated, the electric charge quantity on the electrode can not be directly reduced, and the phenomenon of abnormal operation such as back corona and spark can not be restrained at the first time.

Disclosure of Invention

With the continuous development of electronic component technology and the maturity of high-voltage resistant high-power semiconductor devices and high-voltage resistant material technology, the invention provides a novel rapid protection system of an electrostatic dust collector, which comprises: the electrostatic dust collector comprises an electrostatic dust collector, a discharge electrode, a dust collecting electrode, a dust cleaning device and a power supply controller, wherein the electrostatic dust collector shell is provided with an air inlet and an air outlet; the method is characterized in that: the power supply controller comprises a fast protection circuit and a logic control circuit.

Furthermore, the power supply controller also comprises an industrial power supply, a high-voltage switch power supply and a main controller; the high-voltage switching power supply comprises a rectifying module, a voltage stabilizing module, a high-frequency switching module and a voltage transformation output module; the main controller can be used for controlling the output voltage of the high-voltage switch power supply and controlling the actions or power supply of the ash removal device, the quick protection circuit and the logic control circuit, and the high-voltage switch power supply supplies power to the discharge electrode and the dust collecting electrode of the electrostatic dust collector.

Further, the logic control circuit includes a sampling portion and a judging portion; the sampling part, a resistor R41 and a resistor R42 are connected in series to form a sampling resistor, meanwhile, a resistor R41 and a resistor R42 are also connected with the discharge electrode and the dust collecting electrode in parallel, one end of the resistor R41 is connected with the discharge electrode, the other end of the resistor R41 is connected with one end of a resistor R42, and the other end of the resistor R42 is grounded; the non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through the resistor R43, the inverting input end of the operational amplifier U4 is connected with the output end, the output end of the operational amplifier U4 is divided into two paths, one path of output voltage signal is sent to the analog-to-digital converter, and the other path of output voltage signal is sent to the judging part; in the judging part, a voltage signal output by the operational amplifier U4 is connected to an inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor R45 and a resistor R46 are connected between a power supply VCC1 and the ground in series, a non-inverting input end of the operational amplifier U5 is connected between a resistor R45 and a resistor R46, and an output end of the operational amplifier U5 is connected with the rapid protection circuit.

Further, the logic control circuit includes a sampling portion and a judging portion; the sampling part is characterized in that a current sensor H1 is arranged on a grounding wire of the dust collecting electrode and used for obtaining a current value on the electrode of the electrostatic dust collector and converting the current value into a voltage signal to be output, the non-inverting input end of an operational amplifier U6 is connected to the current sensor H1 through a resistor R51, the inverting input end of the operational amplifier U6 is connected with the output end, the output end of the operational amplifier U6 is divided into two paths, one path outputs the voltage signal to an analog-to-digital converter, and the other path outputs the voltage signal to a judging part; in the judging part, a voltage signal output by the operational amplifier U6 is connected to a non-inverting input end of the operational amplifier U7 through a resistor R52, the non-inverting input end of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor R53 and a resistor R54 are connected between a power supply VCC1 and the ground in series, an inverting input end of the operational amplifier U7 is connected between a resistor R53 and a resistor R54, and an output end of the operational amplifier U7 is connected with the rapid protection circuit.

Further, the logic control circuit includes a voltage control circuit and a current control circuit; the voltage control circuit is as follows: a resistor R41 and a resistor R42 are connected in series to form a sampling resistor, meanwhile, a resistor R41 and a resistor R42 are also connected with the discharge electrode and the dust collecting electrode in parallel, one end of the resistor R41 is connected with the discharge electrode, the other end of the resistor R41 is connected with one end of a resistor R42, the other end of the resistor R42 is grounded, the non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through a resistor R43, the inverting input end of the operational amplifier U4 is connected with the output end, and the output end of the operational amplifier U4 outputs a voltage signal to the voltage judgment part; in the voltage judging part, a voltage signal output by the operational amplifier U4 is connected to the inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor R45 and a resistor R46 are connected between a power supply VCC1 and the ground in series, and the non-inverting input end of the operational amplifier U5 is connected between a resistor R45 and a resistor R46; the current control circuit is as follows: a current sensor H1 is arranged on the grounding wire of the dust collecting electrode and is used for detecting the current value on the electrode of the electrostatic dust collector and converting the current value into a voltage signal to be output; the non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, the inverting input end of the operational amplifier U6 is connected to the output end, and the output end of the operational amplifier U6 outputs a voltage signal to the current judgment part; the current judging section: the voltage signal output by the operational amplifier U6 is connected to the non-inverting input terminal of the operational amplifier U7 through a resistor R52, the non-inverting input terminal of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor R53 and a resistor R54 are connected between a power supply VCC1 and the ground in series, and the inverting input terminal of the operational amplifier U7 is connected between a resistor R53 and a resistor R54.

Further, the output end of the operational amplifier U5 is connected to the anode of the diode D1, the output end of the operational amplifier U7 is connected to the anode of the diode D2, the cathode of the diode D1 is connected to the cathode of the diode D2, and the operational amplifier U7 is output and connected in three paths, the first path is connected to the fast protection circuit, the second path is grounded through the resistor R6, and the third path is connected to the main controller through the resistor R7.

Further, the output end of the operational amplifier U5 is connected with the base of a triode T1 through a resistor R47, and the output of the operational amplifier U7 is connected with the base of a triode T2 through a resistor R55; the collector of triode T1 is connected with power VCC1, and the emitter of triode T1 is connected with the collector of triode T2, and the emitter of triode T2 divides three routes output connection, and first way is connected to quick protection circuit, and the second way is through resistance R6 ground connection, and the third way is connected to main control unit through resistance R7.

The fast protection circuit is characterized by comprising a plurality of protection branches, each branch comprises a photoelectric coupler and is used for signal isolation and level conversion, a control signal output by an output end of an operational amplifier U5 is respectively connected to an input control end of the photoelectric coupler, an output end of the photoelectric coupler passes through a timing circuit formed by grounding a capacitor and a resistor in parallel and is connected in series with a driving circuit formed by the capacitor and the resistor, the driving circuit is connected to a grid electrode of an insulated gate bipolar transistor, a drain electrode of the insulated gate bipolar transistor is connected with a high-voltage switching power supply and outputs the high-voltage switching power supply to a lead of a discharge electrode, a source electrode of the insulated gate bipolar transistor is connected to one end of a high-voltage capacitor, the other end of the high-voltage capacitor is grounded, and the high-voltage capacitor is connected in parallel with an; the capacitance capacities of the timing circuits in the adjacent protection branches are sequentially increased, and preferably, the high-voltage capacitors can be high-voltage ceramic capacitors, high-voltage thin-film capacitors, high-voltage polypropylene capacitors or high-voltage graphene capacitors.

A working method of a quick protection system of an electrostatic dust collector is characterized in that when the dust collector is abnormal in operation, a logic control circuit respectively outputs control signals to a quick protection circuit and a main controller, the quick protection circuit adopts a pure hardware control structure to respond in a short time, and the voltage value on a dust collection electrode is reduced; and the main controller outputs a control signal to the high-voltage switching power supply after receiving the signal of the rapid protection circuit, reduces the output voltage of the high-voltage switching power supply, controls the dust cleaning device to work, and cleans dust on the discharge electrode and the dust collecting electrode.

Compared with the prior art, the invention has the advantages that the rapid protection circuit is arranged at the high-voltage section of the electrode power supply of the electrostatic dust collector, the detection and the reduction of the electrode voltage of the electrostatic dust collector can be realized at the first time when the phenomena of back corona, flashover, spark discharge and arc discharge occur, the generation of the phenomena is effectively inhibited, the switching device in the high-voltage power supply is controlled by the controller to reduce the power output and clean the electrode in time, the rapid protection and recovery of the electrode after the electrostatic dust collector has abnormal operation are realized, and the rapid protection circuit has wide application prospect.

Drawings

FIG. 1 is a schematic structural view of an electrostatic precipitator;

FIG. 2 is a control block diagram of an embodiment of a rapid electrostatic precipitator protection system;

FIG. 3 is a control structure diagram of a rapid electrostatic precipitator protection system in another embodiment;

FIG. 4 is a control structure diagram of a rapid electrostatic precipitator protection system in another embodiment;

FIG. 5 is a control structure diagram of a rapid electrostatic precipitator protection system in another embodiment;

description of the reference numerals

1. An electrostatic precipitator; 11. an air inlet; 12. an air outlet; 13. an ash hopper; 14. a support;

2. a discharge electrode; 3. a dust collecting electrode; 4. a dust removal device;

5. a power supply controller; 51. an industrial power supply; 52. a high voltage switching power supply; 521. a rectification module; 522. a voltage stabilization module; 523. a high frequency switch module; 524. a voltage transformation output module; 53. a main controller; 54. an analog-to-digital converter; 55. a digital-to-analog converter; 56. a fast protection circuit; 57. a logic control circuit.

Detailed Description

Example one

Referring to the attached drawings 1 and 2, the rapid protection system for the electrostatic dust collector comprises an electrostatic dust collector 1, a discharge electrode 2, a dust collecting electrode 3, an ash removal device 4 and a power supply controller 5, wherein an air inlet 11 and an air outlet 12 are formed in a shell of the electrostatic dust collector 1, the discharge electrode 2, the dust collecting electrode 3 and the ash removal device 4 are installed inside the shell of the electrostatic dust collector 1, the power supply controller 5 is installed outside the shell of the electrostatic dust collector 1, an ash bucket 13 is arranged on the lower portion of the shell of the electrostatic dust collector 1, and the shell of the electrostatic dust collector 1 is fixed through a support 14. The power supply controller 5 includes an industrial power supply 51, a high-voltage switching power supply 52, a main controller 53, an analog-to-digital converter 54, a digital-to-analog converter 55, a fast protection circuit 56, and a logic control circuit 57. The high-voltage switching power supply 52 includes a rectifying module 521, a voltage stabilizing module 522, a high-frequency switching module 523, and a transformation output module 524. The industrial ac power in the industrial power supply 51 is rectified, regulated and boosted correspondingly by the rectifying module 521, the voltage-stabilizing module 522, the high-frequency switching module 523 and the voltage-transformation output module 524 of the high-voltage switching power supply 52, and then is connected to the discharge electrode 2 in the electrostatic dust collector 1, the dust collecting electrode 3 is grounded or connected to the other electrode of the high-voltage switching power supply 52, and the high-voltage switching power supply 52 can output positive high voltage or negative high voltage to the discharge electrode 2. The logic control circuit 57 outputs the electrode voltage signal of the electrostatic precipitator 1 to the analog-to-digital converter 54, the analog-to-digital converter 54 converts the electrode voltage signal into a digital signal and inputs the digital signal into the main controller 53, and the main controller 53 outputs a control signal according to the electrode voltage signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55 and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 for adjusting the output voltage of the high-voltage switch power supply 52. The main controller 53 is also used to control the actions or voltage supply (not shown) of the ash cleaner 4, the fast protection circuit 56 and the logic control circuit 57.

The logic control circuit 57 comprises a sampling part and a judging part, a resistor R41 and a resistor R42 are connected in series to form a sampling resistor, meanwhile, a resistor R41 and a resistor R42 are also connected with the discharge electrode 2 and the dust collecting electrode 3 in parallel, one end of the resistor R41 is connected with the discharge electrode 2, the other end of the resistor R41 is connected with one end of a resistor R42, and the other end of the resistor R42 is grounded. The non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through the resistor R43, and the inverting input end of the operational amplifier U4 is connected with the output end to form a voltage follower. The output end of the operational amplifier U4 is divided into two paths, one of which outputs a voltage signal to the analog-to-digital converter 54, and the other of which outputs a voltage signal to the determination section. The judgment part is a single-threshold comparator formed by an operational amplifier U5, a voltage signal output by the operational amplifier U4 is connected to the inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor 45 and a resistor 46 are connected between a power supply VCC1 and the ground in series, the non-inverting input end of the operational amplifier U5 is connected between the resistor 45 and the resistor 46 for inputting a reference voltage for comparison, the resistance values of the resistor 45 and the resistor 46 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U5 is connected with a quick protection circuit 56.

The fast protection circuit 56 comprises a plurality of protection branches, taking the fast protection circuit 56 shown in fig. 2 as an example, the fast protection circuit comprises three protection branches, including photocouplers U1, U2 and U3 for signal isolation and level conversion, control signals output by an output end of an operational amplifier U5 are respectively connected to input control ends of the photocouplers U1, U2 and U3, output ends of the photocouplers U1, U2 and U3 are respectively grounded in parallel through a capacitor C11 and a resistor R11, a capacitor C21 and a resistor R21 are respectively grounded in parallel, a timing circuit formed by connecting the capacitor C21 and the resistor R21 in parallel, a driving circuit formed by connecting the capacitor C21 and the resistor R21 in parallel, a drain electrode of the IGBT 21 and a drain electrode of the IGBT 21 is connected to a lead of the IGBT switch for discharging the IGBT 3652, and a drain electrode of the IGBT 21 and the IGBT 21 are respectively connected to the IGBT 3652 of the IGBT 21 and the IGBT switch for outputting the IGBT 3652 to the IGBT 362, Sources of the

IGBTs

2 and 3 are respectively connected to one ends of high-voltage capacitors C13, C23 and C33, the other ends of the high-voltage capacitors C13, C23 and C33 are grounded, energy dissipation resistors R13, R23 and R33 are respectively connected in parallel to the high-voltage capacitors C13, C23 and C33, and the

IGBTs

1, 2 and 3 are all high-voltage and high-power insulated gate bipolar transistors. The capacity relation of the capacitors C11, C21 and C31 is C11< C21< C31. The number of protection branches can be increased or decreased according to the actual protection needs. The high-voltage capacitors C13, C23 and C33 can be high-voltage ceramic capacitors, high-voltage film capacitors, high-voltage polypropylene capacitors or high-voltage graphene capacitors.

The working principle and the working method of the system are as follows: after the electrostatic dust collector 1 works for a certain time, a certain amount of dust is accumulated on the discharge electrode 2 and the dust collecting electrode 3, so that a phenomenon of back corona or spark discharge occurs, at the moment, the voltage between the two electrodes is reduced to a certain degree, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is collected in real time through a resistor R41 and a resistor R42, the collected voltage signals are respectively input into a single-gate-limited comparator and an analog-digital converter 54 which are formed by an operational amplifier U5 through a voltage follower formed by an operational amplifier U4, when the voltage signals are compared with a reference voltage through a single-gate-limited comparator formed by an operational amplifier U5 and are smaller than the set reference voltage, the operational amplifier U5 outputs a high level to photocouplers U1, U2 and U3 of a quick protection circuit 56, the U1, U2 and U3 in the photocouplers output control signals to IGBTs 1, IGBTs 6 and IGBTs 3, and the capacities of capacitors C11, C21 and C31 are < C4642, therefore, the IGBT1, the IGBT2 and the IGBT3 are sequentially conducted, the high-voltage capacitors C13, C23 and C33 are sequentially connected to the voltage output end of the high-voltage switching power supply 52 and start to charge, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is instantly pulled down, the phenomenon of back corona or spark discharge is prevented from continuing to appear, the actions can be completed within 10ms through the mutual matching of pure hardware structures of the logic control circuit 57 and the quick protection circuit 56, and the quick protection of a polar plate and a circuit of the dust collector is realized. Meanwhile, the analog-to-digital converter 54 converts the received sampling signal into a digital signal and inputs the digital signal into the main controller 53, and meanwhile, the main controller also obtains the voltage drop signal and then outputs a control signal, the main controller 53 outputs the control signal according to the electrode voltage signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55 and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to reduce the output voltage of the high-voltage switch power supply 52 and control the ash removal device 4 to work, so that the dust on the discharge electrode 2 and the dust collection electrode 3 is; after the cleaning operation is completed, the main controller 53 cuts off the power supplies VCC1 and VCC2 in the fast protection circuit 56 and the logic control circuit 57, no control signal is output to the IGBT1, the IGBT2 and the IGBT3 at this time, the IGBT1, the IGBT2 and the IGBT3 are sequentially turned off and on, the high-voltage capacitors C13, C23 and C33 are sequentially turned off and connected to the high-voltage switching power supply 52, and the charges accumulated on the high-voltage capacitors C13, C23 and C33 are respectively consumed through the resistors R13, R23 and R33 which are connected in parallel; the main controller 53 outputs a control signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55, and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to raise the output voltage of the high-voltage switch power supply 52 to a normal dust removal state, the main controller 53 controls the power supplies VCC1 and VCC2 to be electrified, the fast protection circuit 56 and the logic control circuit 57 start to work, and the voltages on the discharge electrode 2 and the dust collection electrode 3 are continuously detected.

Example two

Referring to fig. 3, a fast protection system for an electrostatic precipitator, in the first embodiment, a sampling part of a logic control circuit 57 is replaced by: the current sensor H1 is disposed on the ground wire of the dust collecting electrode 3, and the current sensor H1 may be specifically a hall current sensor for detecting and obtaining the current value on the electrode of the electrostatic precipitator and converting it into a voltage signal for output. The non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, and the inverting input end of the operational amplifier U6 is connected to the output end to form a voltage follower. The output end of the operational amplifier U6 is divided into two paths, one of which outputs a voltage signal to the analog-to-digital converter 54, and the other of which outputs a voltage signal to the determination section. The judgment part is a single threshold comparator formed by an operational amplifier U7, a voltage signal output by the operational amplifier U6 is connected to a non-inverting input end of the operational amplifier U7 through a resistor R52, the non-inverting input end of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor 53 and a resistor 54 are connected between a power supply VCC1 and the ground in series, an inverting input end of the operational amplifier U7 is connected between the resistor 53 and the resistor 54 for inputting a reference voltage for comparison, the resistance values of the resistor 53 and the resistor 54 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U7 is connected with a quick protection circuit 56.

The working principle and the working method of the system are as follows: after the electrostatic precipitator 1 works for a certain time, a certain amount of dust is accumulated on the discharge electrode 2 and the dust collecting electrode 3, and a phenomenon of flashover, spark discharge or arc discharge can be generated, at this time, a current larger than a normal dust removal state can appear on a grounding loop of the dust collecting electrode 3, a current signal on the grounding loop is obtained through the current sensor H1 and is converted into a voltage signal, the voltage signal converted from the collected current value is respectively input into the single threshold comparator and the analog-to-digital converter 54 which are formed by the operational amplifier U6, the voltage signal is compared with a reference voltage through the single threshold comparator and the reference voltage which are formed by the operational amplifier U7, and when the voltage signal is larger than the set reference voltage (namely, the current larger than the preset value appears on the grounding loop of the dust collecting electrode 3), the operational amplifier U7 outputs a high level to the U1 of the photoelectric coupler of the rapid protection circuit 56, In U2 and U3, U1, U2 and U3 in the photocoupler output control signals to IGBT1, IGBT2 and IGBT3, because the capacity relation of capacitors C11, C21 and C31 is C11< C21< C31, the IGBT1, IGBT2 and IGBT3 are sequentially conducted, the high-voltage capacitors C13, C23 and C33 are sequentially connected to the voltage output end of the high-voltage switching power supply 52 and start to charge, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is pulled down instantaneously, the phenomena of flashover, spark discharge or arc discharge are prevented from continuing to appear, the actions can be completed within 10ms through the mutual matching of pure hardware structures of the logic control circuit 57 and the quick protection circuit 56, and the quick protection of a pole plate and a circuit of the dust collector is realized. Meanwhile, the analog-to-digital converter 54 converts the received sampling signal into a digital signal and inputs the digital signal into the main controller 53, and meanwhile, the main controller also obtains the current signal and then outputs a control signal, the main controller 53 outputs the control signal according to the electrode voltage signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55 and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to reduce the output voltage of the high-voltage switch power supply 52 and control the ash removal device 4 to work, so that the dust on the discharge electrode 2 and the dust collector 3 is cleaned and; after the cleaning operation is completed, the main controller 53 cuts off the power supplies VCC1 and VCC2 in the fast protection circuit 56 and the logic control circuit 57, no control signal is output to the IGBT1, the IGBT2 and the IGBT3 at this time, the IGBT1, the IGBT2 and the IGBT3 are sequentially turned off and on, the high-voltage capacitors C13, C23 and C33 are sequentially turned off and connected to the high-voltage switching power supply 52, and the charges accumulated on the high-voltage capacitors C13, C23 and C33 are respectively consumed through the resistors R13, R23 and R33 which are connected in parallel; the main controller 53 outputs a control signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55, and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to raise the output voltage of the high-voltage switch power supply 52 to a normal dust removal state, the main controller 53 controls the power supplies VCC1 and VCC2 to be electrified, the fast protection circuit 56 and the logic control circuit 57 start to work, and the current on the ground loop of the dust collecting electrode 3 continues to be detected.

EXAMPLE III

Referring to fig. 4, a fast protection system for an electrostatic precipitator, on the basis of the first and second embodiments, combines the logic control circuit 57 of the first and second embodiments to form a new logic control circuit 57. The method specifically comprises the following steps:

the resistor R41 and the resistor R42 are connected in series to form a sampling resistor, the resistor R41 and the resistor R42 are connected with the discharge electrode 2 and the dust collecting electrode 3 in parallel, one end of the resistor R41 is connected with the discharge electrode 2, the other end of the resistor R41 is connected with one end of the resistor R42, and the other end of the resistor R42 is grounded. The non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through the resistor R43, and the inverting input end of the operational amplifier U4 is connected with the output end to form a voltage follower. The output terminal of the operational amplifier U4 outputs a voltage signal to the voltage determination section. The voltage judging part is a single-threshold comparator formed by an operational amplifier U5, a voltage signal output by the operational amplifier U4 is connected to an inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor 45 and a resistor 46 are connected between a power supply VCC1 and the ground in series, a non-inverting input end of the operational amplifier U5 is connected between the resistor 45 and the resistor 46 and used for inputting a reference voltage for comparison, the resistance values of the resistor 45 and the resistor 46 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U5 is connected with the anode of a diode D1.

The current sensor H1 is disposed on the ground wire of the dust collecting electrode 3, and the current sensor H1 may be specifically a hall current sensor for detecting and obtaining the current value on the electrode of the electrostatic precipitator and converting it into a voltage signal for output. The non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, and the inverting input end of the operational amplifier U6 is connected to the output end to form a voltage follower. The output terminal of the operational amplifier U6 outputs a voltage signal to the current determination section. The current judgment part is a single threshold comparator formed by an operational amplifier U7, a voltage signal output by the operational amplifier U6 is connected to a non-inverting input end of the operational amplifier U7 through a resistor R52, the non-inverting input end of the operational amplifier U7 is grounded through a filter capacitor C51, the resistor 53 and the resistor 54 are connected between a power supply VCC1 and the ground in series, an inverting input end of the operational amplifier U7 is connected between the resistor 53 and the resistor 54 for inputting a reference voltage for comparison, the resistance values of the resistor 53 and the resistor 54 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U7 is connected with the anode of a diode D2.

The negative electrode of the diode D1 is connected with the negative electrode of the diode D2 and is divided into three paths, the first path is connected to the fast protection circuit 56, the second path is grounded through a resistor R6, the third path is connected to the main controller 53 through a resistor R7, and the diode D1, the diode D2 and surrounding circuits form an OR gate circuit.

The working principle and the working method of the system are as follows: after the electrostatic precipitator 1 works for a certain time, a certain amount of dust is accumulated on the discharge electrode 2 and the dust collecting electrode 3, and phenomena of back corona, flashover, spark discharge or arc discharge can be generated, at the moment, a certain drop can occur in the voltage between the two electrodes or a current larger than the normal dust removing state can occur on the grounding loop of the dust collecting electrode 3, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is collected in real time through a sampling resistor formed by a resistor R41 and a resistor R42, the collected voltage signals are respectively input into a single threshold comparator and an analog-to-digital converter 54 which are formed by an operational amplifier U5 through a voltage follower formed by the operational amplifier U4, when the voltage signal is compared with the reference voltage through a single threshold comparator formed by the operational amplifier U5 and is smaller than the set reference voltage, the operational amplifier U5 outputs a high level to the diode D1 and the diode D2 and their surrounding circuits to form an or gate. The current signal on the grounding loop is obtained through a current sensor H1 and is converted into a voltage signal, the voltage signal converted from the collected current value is respectively input into a single threshold comparator and an analog-to-digital converter 54 which are formed by an operational amplifier U7 through a voltage follower formed by an operational amplifier U6, when the voltage signal is greater than a set reference voltage (namely, the current greater than a preset value appears on the grounding loop of the dust collecting electrode 3) through the single threshold comparator and the reference voltage formed by the operational amplifier U7, the operational amplifier U7 outputs a high level to a diode D1, a diode D2 and a circuit around the diode D2 to form an OR gate circuit. When any one of the operational amplifier U5 or the operational amplifier U7 outputs high level (namely, when either voltage drop or overcurrent problem exists), the diode D1 and the diode D2 and the surrounding circuit composition or gate circuit output high level fault signals to the photocouplers U1, U2 and U3 of the fast protection circuit 56, the photocouplers U1, U2 and U3 output control signals to the IGBTs 1, IGBT2 and IGBT3, because the capacity relations of the capacitors C11, C21 and C31 are C11< C21< C31, the IGBT1, IGBT2 and IGBT3 are sequentially conducted, the high voltage capacitors C13, C23 and C33 are sequentially connected to the voltage output end of the high voltage switch power supply 52 and start charging, the voltage between the discharging electrode 2 and the dust collecting electrode 3 is instantaneously pulled down, the phenomena of reverse corona, flashover, spark discharging or arc discharging are prevented from continuing, and the pure action of the hardware circuit 57 and the fast protection circuit 56 is controlled by logic to be within 10ms, the quick protection of the polar plate and the circuit of the dust remover is realized. Meanwhile, a high-level fault signal output by an OR gate circuit formed by the diode D1, the diode D2 and surrounding circuits is input into the main controller 53, the main controller also obtains the fault signal and then outputs a control signal, the main controller 53 outputs the control signal according to the fault signal, the control signal is converted into an analog reference voltage value through the digital-to-analog converter 55 and then is input into the high-frequency switch module 523 of the high-voltage switch power supply 52 to reduce the output voltage of the high-voltage switch power supply 52 and control the dust cleaning device 4 to work, and dust on the cleaning discharge electrode 2 and the dust collecting electrode 3 falls into a dust hopper; after the cleaning operation is completed, the main controller 53 cuts off the power supplies VCC1 and VCC2 in the fast protection circuit 56 and the logic control circuit 57, no control signal is output to the IGBT1, the IGBT2 and the IGBT3 at this time, the IGBT1, the IGBT2 and the IGBT3 are sequentially turned off and on, the high-voltage capacitors C13, C23 and C33 are sequentially turned off and connected to the high-voltage switching power supply 52, and the charges accumulated on the high-voltage capacitors C13, C23 and C33 are respectively consumed through the resistors R13, R23 and R33 which are connected in parallel; the main controller 53 outputs a control signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55, and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to raise the output voltage of the high-voltage switch power supply 52 to a normal dust removal state, the main controller 53 controls the power supplies VCC1 and VCC2 to be electrified, the fast protection circuit 56 and the logic control circuit 57 start to work, and the voltages on the discharge electrode 2 and the dust collecting electrode 3 and the current on the grounding loop of the dust collecting electrode 3 are continuously detected.

Example four

Referring to fig. 5, a fast protection system for an electrostatic precipitator is based on the first and second embodiments, and combines the logic control circuits 57 of the first and second embodiments to form a new logic control circuit 57 (different from the third embodiment). The method specifically comprises the following steps:

the resistor R41 and the resistor R42 are connected in series to form a sampling resistor, the resistor R41 and the resistor R42 are connected with the discharge electrode 2 and the dust collecting electrode 3 in parallel, one end of the resistor R41 is connected with the discharge electrode 2, the other end of the resistor R41 is connected with one end of the resistor R42, and the other end of the resistor R42 is grounded. The non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through the resistor R43, and the inverting input end of the operational amplifier U4 is connected with the output end to form a voltage follower. The output terminal of the operational amplifier U4 outputs a voltage signal to the voltage determination section. The voltage judging part is a single-threshold comparator formed by an operational amplifier U5, a voltage signal output by the operational amplifier U4 is connected to an inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor 45 and a resistor 46 are connected between a power supply VCC1 and the ground in series, a non-inverting input end of the operational amplifier U5 is connected between the resistor 45 and the resistor 46 and used for inputting a reference voltage for comparison, the resistance values of the resistor 45 and the resistor 46 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U5 is connected with the base of a triode T1 through a resistor R47.

The current sensor H1 is disposed on the ground wire of the dust collecting electrode 3, and the current sensor H1 may be specifically a hall current sensor for detecting and obtaining the current value on the electrode of the electrostatic precipitator and converting it into a voltage signal for output. The non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, and the inverting input end of the operational amplifier U6 is connected to the output end to form a voltage follower. The output terminal of the operational amplifier U6 outputs a voltage signal to the current determination section. The current judgment part is a single-threshold comparator formed by an operational amplifier U7, a voltage signal output by the operational amplifier U6 is connected to a non-inverting input end of the operational amplifier U7 through a resistor R52, the non-inverting input end of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor 53 and a resistor 54 are connected between a power supply VCC1 and the ground in series, an inverting input end of the operational amplifier U7 is connected between the resistor 53 and the resistor 54 for inputting a reference voltage for comparison, the resistance values of the resistor 53 and the resistor 54 can be adjusted according to the requirement of actually inputting the reference voltage, and the output end of the operational amplifier U7 is connected to the base of a triode T2 through a resistor R55.

The collector of the triode T1 is connected with a power supply VCC1, the emitter of the triode T1 is connected with the collector of the triode T2, the emitter of the triode T2 is connected in three ways, the first way is connected to the fast protection circuit 56, the second way is grounded through a resistor R6, the third way is connected to the main controller 53 through a resistor R7, and the triode T1, the triode T2 and surrounding circuits form a gate circuit.

The working principle and the working method of the system are as follows: after the electrostatic precipitator 1 works for a certain time, a certain amount of dust is accumulated on the discharge electrode 2 and the dust collecting electrode 3, and phenomena of back corona, flashover, spark discharge and arc discharge can be generated, at the moment, certain voltage between the two electrodes can be reduced, and a current larger than a normal dust removing state can be generated on a grounding loop of the dust collecting electrode 3, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is collected in real time through a sampling resistor formed by a resistor R41 and a resistor R42, the collected voltage signals are respectively input into a single threshold comparator and an analog-to-digital converter 54 which are formed by an operational amplifier U5 through a voltage follower formed by the operational amplifier U4, when the voltage signal is compared with the reference voltage through a single threshold comparator formed by the operational amplifier U5 and is smaller than the set reference voltage, the operational amplifier U5 outputs a high level to the transistor T1, the transistor T2 and its surrounding circuits to form an and gate. The current signal on the grounding loop is obtained through the current sensor H1 and is converted into a voltage signal, the voltage signal converted from the collected current value is respectively input into the single threshold comparator and the analog-to-digital converter 54 which are formed by the operational amplifier U7 through the voltage follower formed by the operational amplifier U6, when the voltage signal is greater than the set reference voltage (namely, the current greater than the preset value appears on the grounding loop of the dust collecting electrode 3) through the single threshold comparator and the reference voltage formed by the operational amplifier U7, the operational amplifier U7 outputs high level to the triode T1, the triode T2 and the circuit around the triode T2 to form a gate circuit. When the operational amplifier U5 and the operational amplifier U7 both output high level (i.e. when voltage drop and overcurrent exist at the same time), the AND circuit composed of the triode T1 and the triode T2 and the surrounding circuits thereof outputs high level fault signals to the photocouplers U1, U2 and U3 of the fast protection circuit 56, the photocouplers U1, U2 and U3 output control signals to the IGBTs 1, IGBT2 and IGBT3, because the capacity relationship of the capacitors C11, C21 and C31 is C11< C21< C31, the IGBT1, IGBT2 and IGBT3 are sequentially conducted, the high voltage capacitors C13, C23 and C33 are sequentially connected to the voltage output end of the high voltage switching power supply 52 and start charging, the voltage between the discharge electrode 2 and the dust collecting electrode 3 is instantaneously pulled down, the phenomena of reverse corona, flashover, spark discharge and arc discharge are prevented from continuing, and the pure action of the hardware structure is completed within 10ms through the logic control circuit 57 and the fast protection circuit 56 mutually matching, the quick protection of the polar plate and the circuit of the dust remover is realized. Meanwhile, a high-level fault signal output by an AND gate circuit composed of the triode T1, the triode T2 and surrounding circuits thereof is input into the main controller 53, the main controller also outputs a control signal after obtaining the fault signal, the main controller 53 outputs the control signal according to the fault signal, the control signal is converted into an analog reference voltage value through the digital-to-analog converter 55 and then is input into the high-frequency switch module 523 of the high-voltage switch power supply 52 for reducing the output voltage of the high-voltage switch power supply 52 and controlling the dust cleaning device 4 to work, and dust on the cleaning discharge electrode 2 and the dust collecting electrode 3 falls into a dust hopper; after the cleaning operation is completed, the main controller 53 cuts off the power supplies VCC1 and VCC2 in the fast protection circuit 56 and the logic control circuit 57, no control signal is output to the IGBT1, the IGBT2 and the IGBT3 at this time, the IGBT1, the IGBT2 and the IGBT3 are sequentially turned off and on, the high-voltage capacitors C13, C23 and C33 are sequentially turned off and connected to the high-voltage switching power supply 52, and the charges accumulated on the high-voltage capacitors C13, C23 and C33 are respectively consumed through the resistors R13, R23 and R33 which are connected in parallel; the main controller 53 outputs a control signal, converts the control signal into an analog reference voltage value through the digital-to-analog converter 55, and inputs the analog reference voltage value into the high-frequency switch module 523 of the high-voltage switch power supply 52 to raise the output voltage of the high-voltage switch power supply 52 to a normal dust removal state, the main controller 53 controls the power supplies VCC1 and VCC2 to be electrified, the fast protection circuit 56 and the logic control circuit 57 start to work, and the voltages on the discharge electrode 2 and the dust collecting electrode 3 and the current on the grounding loop of the dust collecting electrode 3 are continuously detected.

The technical solutions in the above embodiments have clearly and completely described the contents of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. An electrostatic precipitator rapid protection system comprising: the dust collection device comprises an electrostatic dust collector (1), a discharge electrode (2), a dust collection electrode (3), a dust removal device (4) and a power supply controller (5), wherein a shell of the electrostatic dust collector (1) is provided with an air inlet (11) and an air outlet (12), the discharge electrode (2), the dust collection electrode (3) and the dust removal device (4) are installed inside the shell of the electrostatic dust collector (1), the power supply controller (5) is installed outside the shell of the electrostatic dust collector (1), an ash hopper (13) is arranged at the lower part of the shell of the electrostatic dust collector (1), and the shell of the electrostatic dust collector (1) is fixed through a support (14); the method is characterized in that:

the power supply controller (5) further comprises an industrial power supply (51), a high-voltage switch power supply (52) and a main controller (53); the high-voltage switching power supply (52) comprises a rectifying module (521), a voltage stabilizing module (522), a high-frequency switching module (523) and a voltage transformation output module (524);

the power supply controller (5) comprises a fast protection circuit (56) and a logic control circuit (57); the rapid protection circuit (56) is arranged in a power supply high-voltage section after the output of the secondary coil of the electrode voltage transformation output module (524) of the dust remover; the logic control circuit (57) comprises a sampling part, the sampling part acquires a voltage signal of the discharge electrode (2) through two divider resistors and/or acquires a current signal of the dust collecting electrode (3) through a current sensor, and the voltage signal and/or the current signal are processed by the logic control circuit (57) and then respectively output control signals to the quick protection circuit (56) and the main controller (53); the rapid protection circuit (56) is composed of a plurality of protection branches, each branch comprises a photoelectric coupler and is used for signal isolation and level conversion, control signals output by the output end of the operational amplifier U5 are respectively connected to the input control end of the photoelectric coupler, the output end of the photoelectric coupler passes through a timing circuit formed by parallel grounding of a capacitor and a resistor, and is simultaneously connected in series with a driving circuit formed by a capacitor and a resistor and is connected to the grid electrode of the insulated gate bipolar transistor, the drain electrode of the insulated gate bipolar transistor is connected with the high-voltage switch power supply (52) and is output to the lead of the discharge electrode (2), the source electrode of the insulated gate bipolar transistor is connected to one end of a high-voltage capacitor, the other end of the high-voltage capacitor is grounded, and the high-voltage capacitor is connected in parallel with an;

the main controller (53) converts the control signal output by the logic control circuit (57) into an analog reference voltage value through a digital-to-analog converter (55), and inputs the analog reference voltage value into the high-frequency switch module (523) of the high-voltage switch power supply (52) for adjusting the output voltage of the high-voltage switch power supply (52).

2. The electrostatic precipitator rapid protection system according to claim 1, wherein the logic control circuit (57) further comprises a judgment section; the sampling part is specifically as follows: the resistor R41 and the resistor R42 are connected in series to form a sampling resistor, meanwhile, the resistor R41 and the resistor R42 are also connected with the discharge electrode (2) and the dust collecting electrode (3) in parallel, one end of the resistor R41 is connected with the discharge electrode (2), the other end of the resistor R41 is connected with one end of the resistor R42, and the other end of the resistor R42 is grounded; the non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through the resistor R43, the inverting input end of the operational amplifier U4 is connected with the output end, the output end of the operational amplifier U4 is divided into two paths, one path of output voltage signal is sent to the analog-to-digital converter (54), and the other path of output voltage signal is sent to the judging part; in the judging part, a voltage signal output by the operational amplifier U4 is connected to an inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor R45 and a resistor R46 are connected between a power supply VCC1 and the ground in series, a non-inverting input end of the operational amplifier U5 is connected between a resistor R45 and a resistor R46, and an output end of the operational amplifier U5 is connected with the fast protection circuit (56).

3. The electrostatic precipitator rapid protection system according to claim 1, wherein the logic control circuit (57) further comprises a judgment section; the sampling part is specifically as follows: the current sensor H1 is arranged on a grounding wire of the dust collecting electrode (3) and is used for obtaining the current value on the electrode of the electrostatic dust collector and converting the current value into a voltage signal to be output, the non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, the inverting input end of the operational amplifier U6 is connected with the output end, the output end of the operational amplifier U6 is divided into two paths, one path outputs the voltage signal to the analog-to-digital converter (54), and the other path outputs the voltage signal to the judging part; in the judging part, a voltage signal output by the operational amplifier U6 is connected to a non-inverting input terminal of the operational amplifier U7 through a resistor R52, the non-inverting input terminal of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor R53 and a resistor R54 are connected between a power supply VCC1 and the ground in series, an inverting input terminal of the operational amplifier U7 is connected between a resistor R53 and a resistor R54, and an output terminal of the operational amplifier U7 is connected with the fast protection circuit (56).

4. The electrostatic precipitator rapid protection system according to claim 1, wherein the logic control circuit (57) is embodied as a voltage control circuit and a current control circuit; the voltage control circuit is as follows: a resistor R41 and a resistor R42 are connected in series to form a sampling resistor, meanwhile, a resistor R41 and a resistor R42 are also connected with the discharge electrode (2) and the dust collecting electrode (3) in parallel, one end of the resistor R41 is connected with the discharge electrode (2), the other end of the resistor R41 is connected with one end of a resistor R42, the other end of the resistor R42 is grounded, the non-inverting input end of the operational amplifier U4 is connected between the resistor R41 and the resistor R42 through a resistor R43, the inverting input end of the operational amplifier U4 is connected with the output end, and the output end of the operational amplifier U4 outputs a voltage signal to the voltage judgment part; in the voltage judging part, a voltage signal output by the operational amplifier U4 is connected to the inverting input end of the operational amplifier U5 through a resistor R44, the inverting input end of the operational amplifier U5 is grounded through a filter capacitor C41, a resistor R45 and a resistor R46 are connected between a power supply VCC1 and the ground in series, and the non-inverting input end of the operational amplifier U5 is connected between a resistor R45 and a resistor R46; the current control circuit is as follows: a current sensor H1 is arranged on a grounding wire of the dust collecting electrode (3) and is used for detecting the current value on the electrode of the electrostatic dust collector and converting the current value into a voltage signal to be output; the non-inverting input end of the operational amplifier U6 is connected to the current sensor H1 through a resistor R51, the inverting input end of the operational amplifier U6 is connected to the output end, and the output end of the operational amplifier U6 outputs a voltage signal to the current judgment part; the current judging section: the voltage signal output by the operational amplifier U6 is connected to the non-inverting input terminal of the operational amplifier U7 through a resistor R52, the non-inverting input terminal of the operational amplifier U7 is grounded through a filter capacitor C51, a resistor R53 and a resistor R54 are connected between a power supply VCC1 and the ground in series, and the inverting input terminal of the operational amplifier U7 is connected between a resistor R53 and a resistor R54.

5. The rapid protection system of claim 4, wherein the output terminal of the operational amplifier U5 is connected to the anode of a diode D1, the output terminal of the operational amplifier U7 is connected to the anode of a diode D2, the cathode of the diode D1 is connected to the cathode of a diode D2, and the output terminals are divided into three paths, the first path is connected to the rapid protection circuit (56), the second path is connected to the ground through a resistor R6, and the third path is connected to the main controller (53) through a resistor R7.

6. The fast protection system of claim 4, wherein the output terminal of said operational amplifier U5 is connected to the base of a transistor T1 through a resistor R47, and the output terminal of said operational amplifier U7 is connected to the base of a transistor T2 through a resistor R55; the collector of triode T1 is connected with power VCC1, and the emitter of triode T1 is connected with the collector of triode T2, and the emitter of triode T2 divides three routes output connection, and first way is connected to fast protection circuit (56), and the second way is through resistance R6 ground connection, and the third way is connected to main controller (53) through resistance R7.