CN202616986U - Insulated gate bipolar transistor (IGBT) drive circuit structure - Google Patents

Abstract

The utility model discloses an IGBT drive circuit structure, which is applied as a drive power source of a single-tube LC parallel resonance magnetron. The structure is characterized by comprising a peak value sampling module with a sampling end and a power level end. The sampling end is connected with the positive pole of a commercial power full-wave rectifier. The power level end is connected with a preset power control level signal. The peak value sampling module further comprises a counter-modulation output end outputting a counter-modulation signal controlled by the power control level signal and opposite to the sampling end in terms of the phase. The structure further comprises a counter-modulation module with a counter-modulation signal end connected with the counter-modulation output end; a modulation signal end connecting a triangular wave signal for power control; and a drive output end for reducing the duty ratio of the sampling end when the sampling end has a peak value. The peak value sampling module and the counter-modulation module enable an IGBT transistor to synchronously have the peak value power adjusted according to a power supply peak value. An excessively high peak value voltage of the IGBT transistor is then prevented. The obvious real-time protection of the structure provided in the utility model is very sensitive and effective.

Description

A kind of structure of bipolar transistor driving circuit of insulated gate

Technical field

The utility model relates to a kind of power electronic circuit, specifically is a kind of structure that is used for its bipolar transistor driving circuit of insulated gate of magnetron of single tube LC resonance magnetic working method.

Background technology

Insulated gate bipolar transistor (IGBT) is the switching device that extensively applies to the big or middle power circuit of high frequency.In the family expenses field, many kitchen range particularly also have considerable application in the equipment such as electromagnetic oven, large power supply.Usually, the IGBT peak-inverse voltage tends to the reverse breakdown voltage greater than IGBT when this equipment work, and the situation of over-voltage breakdown takes place easily.Based on this, be necessary the drive circuit of IGBT is designed, make it possess special defencive function, the peak-inverse voltage of restriction IGBT pipe can be very effectively during especially to the power supply peak state.At present the direction of this protection mechanism circuit is not seen and is set foot in.

The utility model content

Lack the problem that reduces IGBT peak-inverse voltage defencive function to above prior art, the utility model proposes a kind of structure of bipolar transistor driving circuit of insulated gate, and its technical scheme is following:

A kind of structure of bipolar transistor driving circuit of insulated gate is used for single tube LC parallel resonance driving magnetron power supply, and it comprises:

One peak value sampling module has a sampling end and a power level end, and said sampling end is connected in the positive pole of civil power full-wave rectification; Said power level end connects a preset power control level signal; This peak value sampling module also have output be limited by said power control level signal and with the counter modulation output of said sampling end anti-phase; And

One counter modulation module has a counter modulation signal end, is connected with said counter modulation output; One modulation signal end connects the triangular signal that is used for power control; Other has the drive output that when said sampling end peak value, reduces its duty ratio;

Wherein said drive output is connected in the driver module that drives insulated gate bipolar transistor.

Preferred person as the utility model technical scheme can have the improvement of following aspect:

In one preferred embodiment; It is characterized in that: said peak value sampling module comprises one first comparator; This first comparator has a positive input terminal, a negative input end and an output: also comprise a voltage sample circuit, have divider resistance and be connected between the negative input end of the said sampling end and first comparator; The output of said first comparator connects one first resistance to ground, connects one second resistance to negative input end, is output as said counter modulation output after connecting one the 3rd resistance again; In addition, this first comparator connects said power level end through one the 4th resistance.

In one preferred embodiment, it is characterized in that: said counter modulation module comprises one second comparator, and the positive input terminal of this second comparator is as said counter modulation signal end; Negative input end is as said modulation signal end, and its output is as said drive output.

In one preferred embodiment, it is characterized in that: said drive output connects the driver module of a driving insulated gate bipolar transistor grid; This driver module comprises:

Push-pull type output is to pipe, and the two base stage connects said drive output, is connected in a direct current voltage through a pull-up resistor simultaneously;

Dividing potential drop drives network, is connected between the grid of said push-pull type output to the output stage of pipe and insulated gate bipolar transistor; And

One voltage-stabiliser tube oppositely is connected between the grid and ground of said insulated gate bipolar transistor.

In one preferred embodiment, it is characterized in that: said sampling end is connected in the positive pole of the full-bridge of an access civil power.

The beneficial effect that the utility model brings is:

1. peak value sampling module and counter modulation module make the IGBT pipe synchronously adjust peak power according to the power supply peak value, thereby have avoided the excessive crest voltage of IGBT pipe, and its significant real-time guard is very effectively sensitive, have reduced the breakdown risk of IGBT pipe.

2. adopt the peak value sampling module delay of devices such as comparator low, respond rapidly, simple in structure.

3. adopt its structure of counter modulation module of comparator very simple, the fast nothing of response postpones, and cost is lower.

Description of drawings

Embodiment is described further the utility model below in conjunction with accompanying drawing:

Fig. 1 is the functional block diagram of the utility model embodiment one;

Fig. 2 is the circuit theory sketch map of the utility model embodiment two.

Embodiment

Embodiment one:

Like Fig. 1, the functional block diagram of the utility model embodiment one:

Present embodiment is used for single tube LC parallel resonance magnetron drive power supply; One peak value sampling module 30; Have a sampling end 32 and a power level end 31, its sampling end 32 is connected in the positive pole of civil power full-wave rectification, and clearly its waveform is sinusoidal wave current waveform in full-wave rectifier A; Its power level end 31 connects preset power control dc level signal, and this signal is based on user's setting data, if the PWM modulation signal then can obtain its direct current effective value access power level end 31 then via a filter circuit; This peak value sampling module also has a counter modulation output 33, and the effect of this counter modulation output 33 is counter modulation signals with sampling end 32 anti-phases of output, and its waveform is shown in B, and its amplitude is passed through processing and amplifying.

The next stage of peak value sampling module 30 is a counter modulation module 20, and this counter modulation module 20 has a counter modulation signal end 22, is connected with counter modulation output 33; Also have a modulation signal end 21, connect the triangular signal C that is used for power control, this triangular signal C is common in the signal of the PWM form of electromagnetic oven IGBT driving; This counter modulation module has a drive output 23; The function of this counter modulation module 20 is to make drive output 23 one of output can finally be used to drive the variable duty cycle signal D of IGBT pipe 11, and the change mechanism of its duty ratio is: compare with triangular signal C from modulation signal end 21 from the signal of counter modulation signal end 22: its duty ratio reduces during the peak value of A waveform; The power of IGBT pipe 11 during with reduction A waveform peak; Relatively, when A waveform trough, the duty ratio of drive output 23 can increase.But the driver module 12 that before IGBT manages 11 grids, has a matched level makes the signal from drive output 23 drive 11 work of IGBT pipe rightly; It is thus clear that; Peak value sampling module 30 makes IGBT pipe 11 synchronously adjust peak power according to the power supply peak value with counter modulation module 20; Thereby avoided IGBT to manage 11 excessive crest voltages, its significant real-time guard is very effectively sensitive, has reduced IGBT and has managed 11 breakdown risks.

Embodiment two:

Like Fig. 2, the circuit theory sketch map of the utility model embodiment two.In the present embodiment; Peak value sampling module 30 comprises one first comparator U1; This first comparator U1 has a positive input terminal, a negative input end and an output: also comprise a voltage sample circuit, have the divider resistance that comprises R24 and R7 and be connected between the negative input end of the sampling end 32 and first comparator; The output of the first comparator U1 connects one first resistance R 57 to ground, connects one second resistance R 56 simultaneously to negative input end, is output as counter modulation output 33 after connecting one the 3rd resistance R 35 again; In addition, this first comparator U1 connects power level end 31 through one the 4th resistance R 54.Sampling end 32 is connected in the positive pole of the full-bridge of an access civil power.It is thus clear that these peak value sampling module 30 delays are low, response is rapid, simple in structure.

In the present embodiment, counter modulation module 20 comprises one second comparator U2, and the positive input terminal of this second comparator U2 is as counter modulation signal end 22 (also being counter modulation output 33); Negative input end is as modulation signal end 21, and its output of this second comparator U2 is as drive output 15.It is thus clear that these counter modulation module 20 structures are very simple, response block does not have delay, and cost is lower.

The drive output 15 of counter modulation module in addition, 20 connects the driver module 12 that IGBT manages 11 grids; This driver module comprises push-pull type output to pipe Q2 and Q3, and the two base stage connects drive output 15, is connected in a 15V direct voltage through a pull-up resistor R80 simultaneously; One dividing potential drop drives network, comprises R12, R13 and R14, is connected between the grid of push-pull type output to the output stage of pipe and IGBT pipe 11; Other has a voltage-stabiliser tube ZD3, oppositely is connected between the grid and ground of IGBT pipe 11.This push-pull driver module 12 makes the output impedance that drives the IGBT pipe low, and has realized the reliable conducting and the shutoff of IGBT pipe 11.

The above; Be merely the utility model preferred embodiment; So can not limit the scope that the utility model is implemented according to this, the equivalence of promptly doing according to the utility model claim and description changes and modifies, and all should still belong in the scope that the utility model contains.

Claims (5)

1. the structure of a bipolar transistor driving circuit of insulated gate is used for single tube LC parallel resonance driving magnetron power supply, and it is characterized in that: it comprises:

One peak value sampling module has a sampling end and a power level end, and said sampling end is connected in the positive pole of civil power full-wave rectification; Said power level end connects a preset power control level signal; This peak value sampling module also have output be limited by said power control level signal and with the counter modulation output of said sampling end anti-phase; And

One counter modulation module has a counter modulation signal end, is connected with said counter modulation output; One modulation signal end connects the triangular signal that is used for power control; Other has the drive output that when said sampling end peak value, reduces its duty ratio;

Wherein said drive output is connected in the driver module that drives insulated gate bipolar transistor.

2. according to the structure of the said a kind of bipolar transistor driving circuit of insulated gate of claim 1; It is characterized in that: said peak value sampling module comprises one first comparator; This first comparator has a positive input terminal, a negative input end and an output: also comprise a voltage sample circuit, have divider resistance and be connected between the negative input end of the said sampling end and first comparator; The output of said first comparator connects one first resistance to ground, connects one second resistance to negative input end, is output as said counter modulation output after connecting one the 3rd resistance again; In addition, this first comparator connects said power level end through one the 4th resistance.

3. according to the structure of the said a kind of bipolar transistor driving circuit of insulated gate of claim 1, it is characterized in that: said counter modulation module comprises one second comparator, and the positive input terminal of this second comparator is as said counter modulation signal end; Negative input end is as said modulation signal end, and its output is as said drive output.

4. according to the structure of the said a kind of bipolar transistor driving circuit of insulated gate of claim 1, it is characterized in that: said drive output connects the driver module of a driving insulated gate bipolar transistor grid; This driver module comprises:

Push-pull type output is to pipe, and the two base stage connects said drive output, is connected in a direct current voltage through a pull-up resistor simultaneously;

Dividing potential drop drives network, is connected between the grid of said push-pull type output to the output stage of pipe and insulated gate bipolar transistor; And

One voltage-stabiliser tube oppositely is connected between the grid and ground of said insulated gate bipolar transistor.

5. according to the structure of the said a kind of edge grid bipolar transistor driving circuit of claim 1, it is characterized in that: said sampling end is connected in the positive pole of the full-bridge of an access civil power.

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