CN108421642A - A kind of electric precipitation high-voltage pulse power source - Google Patents

Abstract

The invention relates to a high-voltage pulse power supply for electric dust removal, comprising: a main circuit module: used to complete the power distribution function; a pulse low-voltage module: used to provide a low-voltage DC power supply for a pulse box; The pulse voltage is sent to the pulse transformer, and absorbs and protects the IGBT switch; the control box module: used to complete the signal collection of the input current voltage, secondary output current voltage, transformer temperature, IGBT temperature, emission concentration, etc. of the high-voltage pulse power supply, and According to the feedback signal, the frequency of the inverter is adjusted to generate different working modes; the pulse transformer module: used to complete the step-up of the pulse voltage and generate negative high-voltage pulses; the coupling module: used to complete the connection between the negative high-voltage pulse and the basic DC negative high voltage The coupling, after the coupling is transported to the electric field. The invention improves the pulse output performance, improves the dust removal effect; improves the structure, reduces the calorific value and improves the stability; and has a better dust removal effect for large-capacity electric fields.

Description

A high-voltage pulse power supply for electric dust removal

technical field

The invention relates to a high-voltage pulse power supply, in particular to a high-voltage pulse power supply for electric dust removal.

Background technique

High-voltage electrostatic precipitator is a kind of industrial flue gas purification equipment. It has mature technology, relatively simple production and low maintenance cost. It is widely used in electric power, cement, metallurgy, nonferrous metals, chemical industry and other industries. The high-voltage power supply system is the key to determining the efficiency of the electrostatic precipitator. The difference in its power supply mode, operation mode and control mode has an important impact on the dust removal efficiency and operation stability of the electrostatic precipitator. With the continuous improvement of the country's requirements for industrial dust emission concentration in recent years, the single-phase power supply and three-phase power supply widely used in the market in the past few years have gradually been eliminated, and the market for high-frequency power supplies is gradually expanding. If the emission concentration is 15mg/m ³ , the pulse power supply technology of pulse superposition fundamental wave must be adopted. Pulse power supply has been gradually used in the domestic market.

Compared with traditional high-voltage DC power supplies, high-voltage pulse power supplies have greater advantages in reducing emissions and saving energy. From the perspective of emission reduction effect, the high-voltage pulse power supply can generate higher corona voltage, which can effectively improve the dust collector's absorption of high specific resistance dust, thereby improving the dust removal effect. From the perspective of energy saving, the high-voltage pulse power supply can effectively avoid the occurrence of back corona phenomenon, thereby avoiding the waste of current and saving energy consumption. The current high-voltage pulse power supply generally has some technical defects. The main problem is that the output power is too small. When it is applied in a large electric field, the peak voltage will be too small and the dust removal effect is not good.

Contents of the invention

Above-mentioned technical problem of the present invention is mainly solved by following technical scheme:

A high-voltage pulse power supply for electrostatic precipitator, characterized in that it comprises:

Main circuit module: used to complete the power distribution function;

Pulse low-voltage module: used to provide low-voltage DC power to the pulse box;

Pulse box module: used to convert the DC power into a pulse voltage and send it to the pulse transformer, and absorb and protect the IGBT switch;

Control box module: used to complete the signal collection of input current and voltage of high-voltage pulse power supply, secondary output current and voltage, transformer temperature, IGBT temperature, emission concentration, etc., and adjust the frequency of the inverter according to the feedback signal to generate different working modes ;

Pulse transformer module: used to complete the step-up of pulse voltage and generate negative high-voltage pulse;

Coupling module: used to complete the coupling of the negative high-voltage pulse and the basic DC negative high voltage, and then transmit it to the electric field after coupling.

As an optimization, the main circuit module includes a circuit breaker and an AC contactor connected in sequence.

As an optimization, the pulse low-voltage module includes a connected three-phase transformer and a rectifier bridge, and the inductor is connected across the rectifier bridge.

As an optimization, the pulse box module includes an IGBT driver, an IGBT connected to the IGBT driver, and a snubber capacitor and a snubber resistor connected in sequence across the IGBT.

As an optimization, the control box module includes:

Pulse controller: generate high voltage pulse signal;

Control power supply module: used to control power supply;

Analog signal isolation conversion module: used to convert analog signals into digital signals;

Digital signal isolation conversion module: used to convert digital signals into analog signals;

As an optimization, the control box module also provides RS485 interface, RJ45 Ethernet interface and human-computer interaction interface.

As an optimization, the pulse transformer module includes a pulse transformer and a resonant capacitor connected thereto.

As an optimization, the coupling module includes high-voltage capacitors and high-voltage inductors.

As an optimization, the pulse transformer uses a special iron core made of ultrafine crystal material to ensure sufficient instantaneous output power; in the pulse output circuit, the IGBT uses a German Infineon chip, and adopts a multi-channel parallel structure to ensure instantaneous input during pulse output The power is big enough. Large-capacity capacitors, fast recovery diodes, and high-power resistors are used to form an absorption protection circuit to absorb the energy impact generated when the IGBT is turned off; IGBT drive communication uses optical fiber communication to ensure that the drive signal is not disturbed; the pulse bus uses LC filtering to ensure IGBT action. There will be no pollution to the grid.

As an optimization, when the control box module operates in superposition of the pulse power supply and the basic power supply, the control box module compares and calculates the voltage and current delivered to the dust collector body according to the change of working conditions, and automatically selects the best control parameters. The parameters include input current and voltage of high-voltage pulse power supply, secondary output current and voltage, transformer temperature, IGBT temperature, and emission concentration.

Therefore, the present invention has the following advantages: the pulse output performance is improved, and the dust removal effect is improved; the structure is improved, the calorific value is reduced, and the stability is improved; the dust removal effect for large-capacity electric fields is better.

Description of drawings

Accompanying drawing 1 is a kind of schematic diagram of the present invention.

Detailed ways

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Example:

In order to improve the output performance, through software simulation and field test, after repeated verification, the circuit structure and device selection with good stability, high safety and low energy consumption have been obtained.

The present invention relates to the multifunctional interface design technology of IDE17 type electric dust removal high-voltage pulse power supply and basic DC power supply, which can be superimposed and uniformly controlled with any manufacturer's basic DC power supply, including high-frequency power supply, power frequency single-phase power supply, and power frequency three-phase power supply. High-voltage DC power supply for electric dust removal such as power supply.

The superposition technology of high-voltage capacitors and auxiliary devices can not only ensure that the pulse output is not disturbed, but also reduce the mutual interference between the fundamental wave and the pulse, and at the same time meet the pulse output capability in large electric field applications.

Two-stage RCD absorption circuit is adopted, the first stage is the main absorption circuit, the absorption diode uses a high-current fast recovery diode, the capacitor adopts a large-capacity absorption capacitor, and the resistance adopts a high-temperature resistant high-power resistor; the second stage is a protective absorption circuit, which is used for the absorption diode Ultra-fast low-current diodes, the capacitors use small-capacity high-performance snubber capacitors to protect the IGBT module. The device parameters are preliminarily determined through calculation, and after multiple simulations and tests, the device selection is determined.

Through software analysis and test verification, the heat dissipation structure of the main heating components is determined. The heat dissipation of the whole machine adopts the circulating air cooling system. The circulating air cooling system is composed of a high-speed centrifugal fan, a flat plate radiator, a corrugated radiator for a transformer, and a controller. Mainly research on the combination of high-speed centrifugal fan and plate radiator to form an effective air duct

Self-developed pulse transformer, and adopts multi-channel parallel structure in the main circuit, and applies various filtering, anti-interference and absorption measures, so that the output pulse width is less than 100us, the voltage rise rate is higher than 2kV/us, and the current rise rate is higher than 10A /us. The output pulse power is not less than 80kV for voltage and not less than 100A for current.

Type 17 high-voltage pulse power supply for electrostatic precipitator, its output form is superposition of fundamental wave and pulse, similar to constant current source, its sudden open circuit is more dangerous than DC power supply. However, in actual use, it is impossible to absolutely avoid sudden open circuit or open circuit operation due to operational errors. At this time, if the judgment cannot be made immediately and the protection is activated, the equipment will generate extremely high voltage in a short period of time, which will directly cause the transformer to burn out. In order to overcome this problem, a large number of research experiments have been done on the high and low voltage winding withstand voltage technology of the transformer, the rapid judgment of the hardware circuit, and the comprehensive judgment and processing of the software, and the problem has been completely solved.

Below in conjunction with embodiment, this case is described in detail.

The modular structure of the 17-type high-voltage pulse power supply for electrostatic precipitator is divided into: main circuit module, pulse low-voltage module, pulse box module, control box module, pulse transformer module, and coupling module. Main circuit module: mainly composed of circuit breakers and AC contactors, which mainly completes power distribution functions; pulse low-voltage module: composed of three-phase transformers, rectifier bridges, and inductors, mainly completes the supply of low-voltage DC power to pulse boxes; pulse box module: consists of Composed of IGBT, IGBT drive, diode, absorption capacitor, and absorption resistor, it mainly completes the conversion of DC power into pulse voltage and sends it to the pulse transformer, and absorbs and protects the IGBT when switching; control box module: consists of pulse controller, control power supply module, analog Quantity signal isolation conversion module, digital signal isolation conversion module, complete the signal acquisition of high-voltage pulse power supply input current voltage, secondary output current voltage, transformer temperature, IGBT temperature, emission concentration, etc., and adjust the inverter according to the feedback signal frequency, generate different working methods, and provide RS485 interface, RJ45 Ethernet interface and human-computer interaction interface at the same time; pulse transformer module: composed of pulse transformer and resonant capacitor, complete the boost of pulse voltage and generate negative high voltage pulse; coupling Module: It is mainly composed of high-voltage capacitors and high-voltage inductors. It completes the coupling of negative high-voltage pulses and basic DC negative high voltage, and then transmits them to the electric field after coupling. The high-voltage pulse power supply adopts the self-developed single electric field distributed low-voltage controller to realize the optimal control of the electric control equipment of the electrostatic precipitator through the centralized control of the rapping method, the heating method of the porcelain shaft ash hopper, the material level ash discharge method, etc. The rest of the network is simple and reliable, which improves the dust removal efficiency of the dust collector and saves resources.

The present invention mainly has the following functions:

1. The new pulse power output structure of the 17-type high-voltage pulse power supply for electrostatic precipitator, the instantaneous output power is as high as 24MW or more.

Through the method of software simulation and field test, after repeated tests, the circuit structure and device selection with good stability, high safety and low energy consumption have been obtained.

2. Design technology of multifunctional interface between high-voltage pulse power supply and basic DC power supply for 17-type electrostatic precipitator.

The working mode of the pulse power supply is superimposed with the basic DC power supply and then sent to the electric dust removal field. In order to achieve compatibility between devices, the 17-type pulse power supply has been designed with compatibility issues with various forms of DC high-voltage power supplies superimposed and used. It can be superimposed and uniformly controlled with any manufacturer’s basic DC power supply, including high-frequency power supplies, High-voltage DC power supply for electrostatic precipitator such as power frequency single-phase power supply and power frequency three-phase power supply.

3. Model 17 high-voltage pulse power supply for electrostatic precipitator adopts modular design, compact and reasonable structure, easy replacement and low maintenance. The high-voltage pulse power supply combined with the single electric field distributed low-voltage controller directly controls the multi-circuit low-voltage equipment, and the redundant networking is simple and reliable.

3. Independently developed the embedded pulse power controller, by changing the power parameters such as input voltage, pulse width, pulse frequency, etc., according to different working conditions, it can automatically adjust the high fundamental wave output voltage, automatically adjust the pulse width 1-100us, pulse frequency 0-300Hz, pulse bus voltage 0-2000V to control the adaptive optimal power supply technology of pulse output voltage.

The pulse power supply control system, when the pulse power supply and the basic power supply are superimposed, the control system compares and calculates the voltage and current delivered to the dust collector body according to the change of working conditions, and automatically selects the best control parameters to achieve the best basic power supply. Wave to pulse ratio, while maintaining high dust removal efficiency, saves power consumption to the greatest extent.

6. Independently developed a pulse transformer, and adopted a multi-channel parallel structure in the main circuit, and applied a variety of filtering, anti-interference and absorption measures, so that the output pulse width is less than 100us, the voltage rise rate is higher than 2kV/us, and the current rise rate is high. at 10A/us.

Self-developed pulse transformer, using a special iron core made of ultra-microcrystalline materials to ensure sufficient instantaneous output power; in the pulse output circuit, the IGBT uses large-scale products from Infineon, Germany, and adopts a multi-channel parallel structure to ensure pulse output The instantaneous input power is large enough. Large-capacity capacitors, fast recovery diodes, and high-power resistors are used to form an absorption protection circuit to absorb the energy impact generated when the IGBT is turned off; IGBT drive communication uses optical fiber communication to ensure that the drive signal is not disturbed; the pulse bus uses LC filtering to ensure IGBT action. There will be no pollution to the grid. The above measures make the output pulse pulse width less than 100us, the voltage rise rate higher than 2kV/us, and the current rise rate higher than 10A/us.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (10)

1. A high-voltage pulse power supply for electrostatic precipitator, characterized in that, comprising: Main circuit module: used to complete the power distribution function; Pulse low-voltage module: used to provide low-voltage DC power to the pulse box; Pulse box module: used to convert the DC power into a pulse voltage and send it to the pulse transformer, and absorb and protect the IGBT switch; Control box module: used to complete the signal collection of input current and voltage of high-voltage pulse power supply, secondary output current and voltage, transformer temperature, IGBT temperature, emission concentration, etc., and adjust the frequency of the inverter according to the feedback signal to generate different working modes ; Pulse transformer module: used to complete the step-up of pulse voltage and generate negative high-voltage pulse; Coupling module: used to complete the coupling of the negative high-voltage pulse and the basic DC negative high voltage, and then transmit it to the electric field after coupling. 2. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the main circuit module includes a circuit breaker and an AC contactor connected in sequence. 3. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the pulse low-voltage module includes a three-phase transformer and a rectifier bridge connected to it, and the inductance is connected across the rectifier bridge. 4. A kind of high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that, the pulse box module includes an IGBT driver and an IGBT connected to the IGBT driver, and a snubber capacitance and a snubber connected sequentially across the IGBT resistance. 5. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the control box module includes: Pulse controller: generate high voltage pulse signal; Control power supply module: used to control power supply; Analog signal isolation conversion module: used to convert analog signals into digital signals; Digital signal isolation conversion module: used to convert digital signals into analog signals. 6. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the control box module also provides RS485 interface, RJ45 Ethernet interface and human-computer interaction interface. 7. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the pulse transformer module includes a pulse transformer and a resonant capacitor connected thereto. 8. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the coupling module includes a high-voltage capacitor and a high-voltage inductor. 9. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that the pulse transformer adopts a special iron core made of ultrafine crystal material to ensure sufficient instantaneous output power; in the pulse output circuit, the IGBT is selected from German British Feiling chip adopts multi-channel parallel structure to ensure that the instantaneous input power is large enough during pulse output; a large-capacity capacitor, fast recovery diode, and high-power resistor are used to form an absorption protection circuit to absorb the energy impact generated when the IGBT is turned off; The IGBT drive communication adopts optical fiber communication to ensure that the drive signal is not disturbed; the pulse bus adopts LC filtering to ensure that the IGBT will not pollute the power grid when it operates. 10. A high-voltage pulse power supply for electrostatic precipitator according to claim 1, characterized in that, when the control box module is superimposed on the pulse power supply and the basic power supply, the control box module will be sent to the dust collector according to the change of the working condition The voltage and current of the main body are compared and calculated, and the best control parameters are automatically selected. The control parameters include the input current and voltage of the high-voltage pulse power supply, the secondary output current and voltage, the temperature of the transformer, the temperature of the IGBT, and the emission concentration. Two-stage RCD absorption circuit is adopted. , the first stage is the main absorption circuit, the absorption diode uses a high-current fast recovery diode, the capacitor adopts a large-capacity absorption capacitor, and the resistance adopts a high-temperature resistant high-power resistor; the second stage is a protection absorption circuit, and the absorption diode uses an ultra-fast low-current diode. The capacitor adopts a small-capacity high-performance absorption capacitor to protect the IGBT module.