CN204886687U - Buffering snubber circuit , pulse generator and electrostatic precipitator power supply unit - Google Patents

Abstract

The application discloses buffering snubber circuit, pulse generator and electrostatic precipitator power supply unit. This pulse buffering snubber circuit includes single -phase controllable type switching element, electric capacity and the resistance that switches on. Wherein, electric capacity with behind the resistor parallel with with controllable type switching element is established ties. Before the flashover takes place, the utility model discloses controllable type switching element is off -state, and the capacitance voltage is zero. And present buffering snubber circuit capacitance voltage before the flashover takes place be DC source voltage, thus permit loaded voltage and flashover at every turn to cushion snubber circuit when the electric capacity both ends need the timing of absorptive energy, the utility model discloses the capacitance value of the electric capacity that adopts is littleer, improves the discharge rate of electric capacity, makes pulse generator can bear the flashover of bigger frequency.

Description

A kind of snubber circuit, the pulse power and electrostatic precipitation power-supply device

Technical field

The application relates to electrostatic precipitation field, more particularly, relates to a kind of snubber circuit, the pulse power and electrostatic precipitation power-supply device.

Background technology

A kind of existing pulse power supply circuit figure is shown see Fig. 1.In electrostatic precipitation system, the Electric Field in ESP during load of the pulse power, this load can be equivalent to electric capacity C _loadwith resistance R _loadparallel connection, often there is flashover during the maximum feature of this load.

When flashover, energy can pass through pulse transformer, is coupled to primary side by pulse transformer secondary side, because now pulse power internal resistance significantly reduces, can produce huge electric current on major loop.This electric current is easy to cause major loop device overcurrent damage.For protection major loop device, now need IGBT to turn off, make electric current flow through snubber loop.

Existing snubber loop is by diode D _cl, electric capacity C _clresistance R _clcomposition, namely common RCD snubber circuit.When the electric current produced when flashover is by RCD snubber loop, the C of snubber circuit _clvoltage raises.Now IGBT both end voltage equals snubber loop C _clvoltage.For avoiding IGBT both end voltage too high, C _clcapacitance need very large, and then cause C _clelectric discharge is comparatively slow, causes the pulse power cannot bear the flashover of larger frequency.

Utility model content

In view of this, the application provides a kind of snubber circuit, the pulse power and electrostatic precipitation power-supply device, with the flashover enabling the pulse power bear larger frequency.

To achieve these goals, the existing scheme proposed is as follows:

A kind of snubber circuit, comprising: the controllable type switching device of single-phase conducting, electric capacity and resistance;

Wherein, described electric capacity is connected with described controllable type switching device with after described resistor coupled in parallel.

Preferably, described controllable type switching device is half control type switching device.

Preferably, described controllable type switching device is full-controlled switch device.

Preferably, described controllable type switching device is high speed thyristor.

A kind of pulse power, comprising: the snubber circuit described in above content, IGBT and DC power supply;

Wherein said snubber circuit, described IGBT and described DC power supply are in parallel.

A kind of electrostatic precipitation power-supply device, comprises the above-described pulse power and the DC high-voltage power supply in parallel with the described pulse power.

Through as shown from the above technical solution, this application discloses a kind of snubber circuit, the pulse power and electrostatic precipitation power-supply device.This pulse buffer absorbing circuit comprises the controllable type switching device of single-phase conducting, electric capacity and resistance.Wherein, described electric capacity is connected with described controllable type switching device with after described resistor coupled in parallel., before flashover occurs, the utility model controllable type switching device is off state, and capacitance voltage is zero.And existing snubber circuit capacitance voltage before flashover occurs is direct current power source voltage, thus when electric capacity two ends allow energy one timing of voltage and each flashover snubber circuit needs absorption loaded, the capacitance of the electric capacity that the utility model adopts is less, improve the velocity of discharge of electric capacity, enable the pulse power bear the flashover of larger frequency.

Accompanying drawing explanation

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiment of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the accompanying drawing provided.

Fig. 1 shows a kind of existing pulse power supply circuit figure;

Fig. 2 shows a kind of pulse power supply circuit figure disclosed in the utility model embodiment.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

A kind of pulse power supply circuit figure disclosed in the utility model embodiment is shown see Fig. 2.

As shown in Figure 2, the snubber circuit of this pulse power comprises: the controllable type switching element T of single-phase conducting, electric capacity C _clwith resistance R _cl.

Wherein, described electric capacity C _clwith described resistance R _clconnect with described controllable type switching element T after in parallel.

Compared with primary circuit, the utility model has following difference:

1, semiconductor device changes half control or full-controlled switch device into by diode, and this switching device can only one-way conduction, and opens speed (<5us).Optionally, high speed thyristor can be adopted.

2, R _clchange into and be connected in parallel on C _cltwo ends.Like this, when snubber circuit does not work, C can be made _clboth end voltage remains 0V.

The operation principle of this snubber circuit is as follows:

After flashover being detected, T is open-minded for gate-controlled switch device, C _clthe former series resonant circuit of series connection access, forms new series resonant tank.After the positive half cycle of harmonic period terminates, because switching device can only single-phase conducting, therefore Ccl no longer participates in resonance.Former series resonant tank continues negative half period resonance by the backward diode of IGBT module.

After flashover, after the positive half cycle of harmonic period terminates, C _clpass through R _clelectric discharge.Discharge time constant τ=C _cl* R _cl, through 3 ~ 5 τ C _clcomplete electric discharge, voltage return is 0.

Compare and primary circuit, the utility model significantly can reduce C _clreason as follows:

Before flashover occurs, C in primary circuit _clthe voltage at two ends equals DC power supply DC both end voltage, and C in the utility model _clthe voltage at two ends equals 0.When a flashover occurs, suppose that each flashover snubber circuit all needs the energy absorbed to be designated as E, DC power supply DC voltage is 2500V, C _cltwo ends allow ceiling voltage to be 3000V.Then primary circuit:

$C_{cl}=\frac{2E}{{\mathrm{\&Delta;U}}^2}=\frac{2E}{{500}^2}$

And the utility model:

$C_{cl}=\frac{2E}{{\mathrm{\&Delta;U}}^2}=\frac{2E}{{3000}^2}$

Visible, the circuit C after improvement _clvalue can reduce very many, meanwhile, during owing to there is not flashover, and each harmonic period, R _clon no longer include loss, R _cltemperature rise is significantly lowered, when there is flashover, and R _cllarger discharging current can be born.Like this, R _clvalue also can respond reduction, and discharge time constant τ also significantly reduces, thus makes the pulse power can bear larger flashover frequency, thus can be applied to electrostatic precipitation electric field.

It should be noted that, the pulse power needs parallel connection together with another one DC high-voltage power supply (basis) to power to Electric Field in ESP usually.Such voltage of electric field=U _base+ U _pulse, wherein U _baserepresent that DC high-voltage power supply produces voltage (basic voltage), U _pulseindicating impulse power supply produces voltage (pulse voltage).

For this reason, the invention also discloses a kind of electrostatic precipitation power-supply device, this electrostatic precipitation power-supply device comprises the above-mentioned pulse power and the DC high-voltage power supply in parallel with the pulse power.

Finally, also it should be noted that, in this article, the such as relational terms of first and second grades and so on is only used for an entity or operation to separate with another entity or operating space, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.When not more restrictions, the key element limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment comprising described key element and also there is other identical element.

In this specification, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.

To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the utility model.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (6)

1. a snubber circuit, is characterized in that, comprising: the controllable type switching device of single-phase conducting, electric capacity and resistance;

Wherein, described electric capacity is connected with described controllable type switching device with after described resistor coupled in parallel.

2. snubber circuit according to claim 1, is characterized in that, described controllable type switching device is half control type switching device.

3. snubber circuit according to claim 1, is characterized in that, described controllable type switching device is full-controlled switch device.

4. snubber circuit according to claim 1, is characterized in that, described controllable type switching device is high speed thyristor.

5. a pulse power, is characterized in that, comprising: snubber circuit, IGBT and the DC power supply described in claim 1 to claim 4 any one claim;

Wherein said snubber circuit, described IGBT and described DC power supply are in parallel.

6. an electrostatic precipitation power-supply device, is characterized in that, comprises the pulse power according to claim 5 and the DC high-voltage power supply in parallel with the described pulse power.