CN204504498U - A kind of rail welding electron-beam welder filament supply device - Google Patents

Abstract

The utility model provides a kind of rail welding electron-beam welder filament supply device, by power input, the first rectification circuit, BUCK circuit, half-bridge inversion circuit, LLC resonant converter, the second rectification circuit, heating load and power output end being linked in sequence successively; The single-phase alternating current of the 220V of power input is treated to galvanic current by the first rectification circuit; BUCK circuit regulates this DC bus-bar voltage, direct current after this voltage-regulation is transformed to the alternating current of high frequency through half-bridge inversion circuit process, and LLC resonant converter is carried out the optimization of waveform to the alternating current that half-bridge inversion circuit exports and realized the Sofe Switch of switching tube; Second rectification circuit exports direct current and is added in load after carrying out rectification and filtering again after voltage transformation and isolation.The utility model, by introducing LLC resonant converter, improves the operating frequency of power supply, decreases switching loss and clutter, make switching device can realize Sofe Switch very easily.

Description

A kind of rail welding electron-beam welder filament supply device

Technical field

The utility model belongs to electron-beam welder circuit power field, particularly relates to a kind of rail welding electron-beam welder filament supply device.

Background technology

The general principle of electron-beam welder is: the electronics that filament heating is launched, after the high voltage electric field produced by high voltage source is accelerated, obtain high kinetic energy, electronic beam current is formed by the adjustment of grid bias power supply and focusing power supply, then go to bombard workpiece, the kinetic transformation of electron beam is that heat energy makes workpiece weld become molten condition to form weld seam, thus realizes the welding to workpiece.What electron-beam welder filament supply domestic at present adopted is high frequency electric source, the special PWM pulse modulation technology that control circuit adopts.Because frequency is high, power tube can produce very large power attenuation and electromagnetic interference when turning on and off, and have impact on the further rising of frequency.

Utility model content

The purpose of this utility model is to provide a kind of rail welding electron-beam welder filament supply device, be intended to solve existing electron-beam welder filament supply due to frequency high, power tube can produce very large power attenuation and electromagnetic interference when turning on and off, and have impact on the problem that frequency raises further.

The utility model realizes like this, a kind of rail welding electron-beam welder filament supply device, comprise power input, the first rectification circuit, BUCK circuit, half-bridge inversion circuit, LLC resonant converter, the second rectification circuit, power output end and heating load; Wherein,

Described power input, the first rectification circuit, BUCK circuit, half-bridge inversion circuit, LLC resonant converter, the second rectification circuit, heating load and power output end are linked in sequence successively;

The single-phase alternating current of the 220V of power input is treated to galvanic current by described first rectification circuit; Described BUCK circuit regulates this DC bus-bar voltage, direct current after this voltage-regulation is transformed to the alternating current of high frequency through half-bridge inversion circuit process, and described LLC resonant converter is carried out the optimization of waveform to the alternating current that half-bridge inversion circuit exports and realized the Sofe Switch of switching tube; Described second rectification circuit is carried on heating load the direct current of stable output after carrying out rectification and filtering again after voltage transformation and isolation.

Preferably, described rail welding electron-beam welder filament supply device also comprises control circuit and drive circuit; Described heating load with the connection line of power output end separates a road and is connected with the input of control circuit; Described control circuit output be connected with the input of drive circuit; First output of described drive circuit is connected with the input of BUCK circuit, and the second output is connected with half-bridge inversion circuit input; Wherein,

Described control circuit is used for carrying out controlling functions to BUCK circuit and LLC resonant converter breaker in middle element, and described drive circuit amplifies the control signal that control circuit sends and isolates.

Preferably, described first rectification circuit comprises EMC filter circuit and the first current rectifying and wave filtering circuit; The input of described EMC filter circuit is connected with power input, and output is connected with the input of the first current rectifying and wave filtering circuit, and the output of described first current rectifying and wave filtering circuit is connected with the input of BUCK circuit; Wherein,

The single-phase alternating current of the 220V of power input is carried out electromagnetic interference by described EMC filter circuit, and described first current rectifying and wave filtering circuit is to going the alternating current after electromagnetic interference to carry out uncontrollable rectification and capacitor filtering obtains galvanic current.

Preferably, described second rectification circuit comprises high frequency transformer and the second current rectifying and wave filtering circuit; Described LLC resonant converter, high frequency transformer, the second current rectifying and wave filtering circuit, heating load and power output end are linked in sequence; Wherein,

Described high frequency transformer converts voltage and isolates; Described second current rectifying and wave filtering circuit carries out the direct current of stable output after rectification and filtering to the high-frequency alternating current that high frequency transformer exports.

The utility model overcomes the deficiencies in the prior art, a kind of rail welding electron-beam welder filament supply device is provided, by introducing LLC resonant converter in filament power supply circuit, and the size of voltage is changed by the mode adjusting busbar voltage, both improve the operating frequency of power supply, additionally reduce switching loss and clutter, and make switching device can realize Sofe Switch very easily, simultaneously by regulating the size of busbar voltage to overcome the linear and a large amount of harmonic influence of the wide generation of tune of inverter circuit frequency modulation Q value curve.Electric power main circuit adopts the size of BUCK the regulation of electrical circuit busbar voltage, and inverter circuit adopts semi-bridge inversion and LLC resonant transform circuit, and adopts closed-loop control to realize the automatic adjustment of filament supply and to stablize.

Accompanying drawing explanation

Fig. 1 is the structural representation of the utility model rail welding electron-beam welder filament supply device;

Fig. 2 is the structural representation of the another embodiment of the utility model rail welding electron-beam welder filament supply device;

Fig. 3 is the rough schematic view of LLC resonant converter half-bridge circuit;

Fig. 4 is LLC resonant converter equivalent circuit structure figure;

Fig. 5 is Q value curve map;

Detailed description of the invention

In order to make the purpose of this utility model, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.

As shown in Fig. 1 ~ 5, wherein, Fig. 1 is the circuit structure diagram of the utility model rail welding electron-beam welder filament supply device; Fig. 2 is the structural representation of the another embodiment of the utility model rail welding electron-beam welder filament supply device; Fig. 3 is the rough schematic view of LLC resonant converter half-bridge circuit; Fig. 4 is LLC resonant converter equivalent circuit structure figure; Fig. 5 is Q value curve map.

A kind of rail welding electron-beam welder filament supply device, comprises power input Vin, the first rectification circuit 1, BUCK circuit 2 (bibliography: Wang Zhaoan.Power Electronic Technique [M].Beijing: China Machine Press, 2005), half-bridge inversion circuit 3 (bibliography: Wang Zhaoan.Power Electronic Technique [M].Beijing: China Machine Press, 2005), LLC resonant converter 4, second rectification circuit 5, heating load 9 and power output end Vout; Wherein, described power input Vin, the first rectification circuit 1, BUCK circuit 2, half-bridge inversion circuit 3, LLC resonant converter 4, second rectification circuit 5, heating load 9 and power output end Vout are linked in sequence successively; The single-phase alternating current of the 220V of power input Vin is treated to galvanic current by described first rectification circuit 1; Described BUCK circuit 2 regulates this DC bus-bar voltage, direct current after this voltage-regulation is transformed to the alternating current of high frequency through half-bridge inversion circuit 3 process, and the alternating current that described LLC resonant converter 4 pairs of half-bridge inversion circuits 3 export carries out the optimization of waveform and realizes the Sofe Switch of switching tube; After carrying out rectification and filtering again after described second rectification circuit 5 pairs of voltage transformations and isolation, the direct current of stable output is carried on heating load 9, and heating load 9 heats.

In the utility model, more specifically, described rail welding electron-beam welder filament supply device also comprises control circuit 7 and drive circuit 6 (bibliography: Kang Jingsong.Power Electronic Technique [M].Beijing: China Railway Press, 2010); Described heating load 9 with the connection line of power output end Vout separate a road be connected with the first input end of control circuit 7; Second input of described control circuit 7 is connected with host computer 8; Described control circuit 7 output be connected with the input of drive circuit 6; First output of described drive circuit 6 is connected with the input of BUCK circuit 2, and the second output of drive circuit 6 is connected with half-bridge inversion circuit 3 input; Wherein, described control circuit 7 is for carrying out controlling functions to BUCK circuit 2 and LLC resonant converter 3 breaker in middle element, and the control signal that described drive circuit 6 pairs of control circuits 7 send is amplified and isolates, and host computer 8 is for input control order.

In the utility model embodiment, more specifically, described first rectification circuit 1 comprises EMC filter circuit 1-1 and the first current rectifying and wave filtering circuit 1-2 (bibliography: Kang Jingsong.Power Electronic Technique [M].Beijing: China Railway Press, 2010); The input of described EMC filter circuit 1-1 is connected with power input Vin, and the output of EMC filter circuit 1-1 is connected with the input of the first current rectifying and wave filtering circuit 1-2, and the output of described first current rectifying and wave filtering circuit 1-2 is connected with the input of BUCK circuit 2; Wherein, the single-phase alternating current of the 220V of power input Vin is carried out electromagnetic interference by described EMC filter circuit 1-1, and described first current rectifying and wave filtering circuit 1-2 is to going the alternating current after electromagnetic interference to carry out uncontrollable rectification and capacitor filtering obtains galvanic current.

In the utility model embodiment, more specifically, described second rectification circuit 5 comprises high frequency transformer 5-1 and the second current rectifying and wave filtering circuit 5-2; Described LLC resonant converter 4, high frequency transformer 5-1, the second current rectifying and wave filtering circuit 5-2, heating load 9 and power output end Vout are linked in sequence; Wherein, described high frequency transformer 5-1 converts voltage and isolates; Described second current rectifying and wave filtering circuit 5-2 carries out the direct current of stable output after rectification and filtering to the high-frequency alternating current that high frequency transformer 5-1 exports.

In the utility model, LLC resonant converter 4 has many good qualities relative to traditional LC series and parallel connections resonance.Traditional LC series resonance is owing to being a divider, and voltage gain is less than 1 all the time, and when load is larger, very difficult regulating frequency realizes the wide variation of output voltage.And traditional parallel resonance produces a large amount of circulating currents due to the also joint conference of resonant capacitance, be unfavorable for the utilization in large-power occasions.

The advantage that LLC resonance combines LC series and parallel connections resonance puts forward.Relative to conventional resonance, LLC can regulate when input and load wide variation; ZVS can be realized in the gamut regulated; Well make use of the parasitic parameter of prototype part.

The operation principle of LLC resonant converter 4, as shown in Figure 3, Fig. 3 is the rough schematic view of LLC resonant converter half-bridge circuit.In Fig. 3, Lk is the leakage inductance of transformer, and Lm is magnetizing inductance, and Cr is resonant capacitance.As can be seen from Figure 3, when being operated under case of heavy load, form series resonant tank by leakage inductance, resonant capacitance and load.Resonant frequency is when being operated under no-load condition, leakage inductance, resonant capacitance, magnetizing inductance is had to form series resonant tank.Resonant frequency is

For resonant network, carry out equivalent inpnt model by the first-harmonic method of equal effect, as shown in Figure 4.For the input of resonant network, be called half-bridge mid point, its voltage waveform is an amplitude is the square wave of Vdc, obtains through Fourier decomposition:

$\mathrm{Vi}\left(t\right)=\frac{2}{\mathrm{\π}}{V}_{\mathrm{dc}}\sin \left(2\mathrm{\πft}\right)---\left(1\right)$

Virtual value is $\mathrm{Vi}\left(t\right)=\frac{\sqrt{2}}{\mathrm{\π}}{V}_{\mathrm{dc}}---\left(2\right)$

The relation of transformer two side resistance can be obtained by full-wave rectifying circuit:

$R_{\mathrm{ac}}=\frac{n^{2}8}{{\mathrm{\π}}^2}{R}_{\mathrm{out}}---\left(3\right)$

The gain that can be obtained resonant network by formula (2), (3) is:

$M(f,k,Q)=\frac{{\mathrm{nV}}_{\mathrm{out}}}{V_i}=\frac{1}{\sqrt{(1+\frac{1}{k}-\frac{1}{{\mathrm{kf}}^2}{)}^2+Q^2{(f-\frac{1}{f})}^2}}---\left(4\right)$

Wherein, resonant frequency is: $f_r=\frac{1}{2\mathrm{\π}\sqrt{L_r{C}_r}},k=\frac{L_k}{L_r}$

Quality factor is: $Q=\frac{\sqrt{L_r/C_r}}{\mathrm{Re}}=\frac{{2\mathrm{\πf}}_r{L}_r}{R},$ Normalized frequency $f_n=\frac{f}{f_r}.$

Gain curve corresponding to different Q can be obtained, namely Q value curve, as shown in Figure 5 according to formula above.As can be seen from Figure 5, corresponding to different Q value curves, be ZVS region on the right side of its hump, left side is ZCS region; When switching frequency equals resonant frequency, duty and the load of LLC transformer have nothing to do, and this is the advantage of LLC resonant converter 4 uniqueness.Affect LLC gain because have f _n, k, Q, under reasonably these parameters of collocation can make resonant network be operated in more satisfactory state.

As can be seen from Q value curve, k value is less, and Q value curve is more precipitous, and when obtain identical gain, change of frequency is less.But k value is too small, when can make identical Lr, magnetizing inductance Lm is less, and the loss of switching tube can increase, so k is taken between 3 ~ 7.

In the utility model, for the selection of voltage regulating mode, that general inversion pressure regulation adopts is PWM and PFM.PWM (pulsewidth modulation) circuit, it is the change being realized output by the size of change dutycycle, the change of pulse width will inevitably produce higher hamonic wave, the break-make of such switch tube and the normal work of high frequency transformer all can have a great impact, and add loss and make waveform create burr.PFM (pulse frequency modulated) circuit, is the umber of pulse being changed each cycle by the size of change frequency, thus changes the size of output voltage.And due to output voltage and incoming frequency be not the change of linear relationship, this is difficult to realize voltage in large-scale linear change.

In the utility model, adopt dutycycle and frequency to fix, carried out the control method of regulation output voltage swing by the size of regulation voltage amplitude.So both make use of the advantage that LLC resonance circuit realizes Sofe Switch, turn avoid the shortcoming that LLC frequency modulation curve is not linear.By fixed switching frequency, resonant frequency, k value, allow switching frequency at resonant frequency f _r1and f _r2between, make inverter power tube and transformer secondary diode operation under Sofe Switch state, adjusted the size of busbar voltage simultaneously by BUCK circuit, so just significantly can adjust voltage while the loss reducing switching tube.Also under filament supply being made to be operated in low harmony wave, high stability, high-frequency situation simultaneously.

In addition, for the control circuit 7 in the utility model, this control circuit 7 comprises signal processing circuit, drive circuit, sample circuit etc.The dsp chip of the TMS320F2812 that signal processing circuit adopts TI company to produce.TMS320F2812 is one of dsp chip that current cost performance is the highest.Not only there is powerful digital signal processing capability, and have perfect Time Management.Produce three road PWM waveforms mainly through the full comparing unit in task manager, a road waveform is by changing the IGBT break-make of the size control BUCK circuit of pulse width; Another two-way waveform is symmetrical up and down, is controlled the IGBT of inversion half-bridge by drive circuit.The pulsewidth and the frequency that control the PWM waveform of inversion half-bridge pass through debugging, after making the break-make of IGBT meet Sofe Switch, just no longer to its adjustment, when adjusting voltage swing, can only need the pulsewidth of the PWM waveform regulating BUCK circuit.

Drive circuit adopts the M57962L of Mitsubishi, the features such as it has high-voltage isolating, overcurrent protection, and driving force is strong.Sampling adopts difference chip ACPL-728 to carry out voltage x current sampling, has the advantages that precision is high, isolation performance is good.Closed-loop system adopts pi regulator, to be sampled realization by dsp chip, A/D.

In order to verify the correctness of the design, design a stylobate in the filament supply of LLC resonant converter 4.Input transformer voltage is 40V, output voltage 10V, and output current is 15A.

According to designing requirement, the material of selected high frequency transformer is ferrite, and shape is loop configuration, and turn ratio is 4:1.Lm＝60uH，Lr＝15uH，Cr＝1uF。IGBT adopts the FS10R06VE3_B2 module of Infineon.BUCK contactor frequency is set to 30kHz, and BUCK circuit change in duty cycle scope is 0 ~ 0.9, and inverter duty cycle is set to 0.9 and immobilizes.

Can be calculated fr1=41.7kHz, fr2=18.4kHz, gets fr2<fr<fr1, now adjusts the frequency f r of inverter, by fr from 18kHz to rise, find out and can either realize no-voltage and open and can ensure to export the resonance point met the demands.

Compared to the shortcoming and defect of prior art, the utility model has following beneficial effect: the utility model is by introducing LLC resonant converter, both improve the operating frequency of power supply, additionally reduce switching loss and clutter, make switching device can realize Sofe Switch very easily, further increase the stability of power supply, reduce ripple factor.

The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all do within spirit of the present utility model and principle any amendment, equivalent to replace and improvement etc., all should be included within protection domain of the present utility model.

Claims (4)

1. a rail welding electron-beam welder filament supply device, is characterized in that, comprises power input, the first rectification circuit, BUCK circuit, half-bridge inversion circuit, LLC resonant converter, the second rectification circuit, power output end and heating load; Wherein,

Described power input, the first rectification circuit, BUCK circuit, half-bridge inversion circuit, LLC resonant converter, the second rectification circuit, heating load and power output end are linked in sequence successively;

The single-phase alternating current of the 220V of power input is treated to galvanic current by described first rectification circuit; Described BUCK circuit regulates this DC bus-bar voltage, direct current after this voltage-regulation is transformed to the alternating current of high frequency through half-bridge inversion circuit process, and described LLC resonant converter is carried out the optimization of waveform to the alternating current that half-bridge inversion circuit exports and realized the Sofe Switch of switching tube; Described second rectification circuit is carried on heating load the direct current of stable output after carrying out rectification and filtering again after voltage transformation and isolation.

2. rail welding electron-beam welder filament supply device as claimed in claim 1, it is characterized in that, described rail welding electron-beam welder filament supply device also comprises control circuit and drive circuit; Described heating load with the connection line of power output end separates a road and is connected with the input of control circuit; Described control circuit output be connected with the input of drive circuit; First output of described drive circuit is connected with the input of BUCK circuit, and the second output is connected with half-bridge inversion circuit input; Wherein,

Described control circuit is used for carrying out controlling functions to BUCK circuit and LLC resonant converter breaker in middle element, and described drive circuit amplifies the control signal that control circuit sends and isolates.

3. rail welding electron-beam welder filament supply device as claimed in claim 2, it is characterized in that, described first rectification circuit comprises EMC filter circuit and the first current rectifying and wave filtering circuit; The input of described EMC filter circuit is connected with power input, and output is connected with the input of the first current rectifying and wave filtering circuit, and the output of described first current rectifying and wave filtering circuit is connected with the input of BUCK circuit; Wherein,

The single-phase alternating current of the 220V of power input is carried out electromagnetic interference by described EMC filter circuit, and described first current rectifying and wave filtering circuit is to going the alternating current after electromagnetic interference to carry out uncontrollable rectification and capacitor filtering obtains galvanic current.

4. rail welding electron-beam welder filament supply device as claimed in claim 3, it is characterized in that, described second rectification circuit comprises high frequency transformer and the second current rectifying and wave filtering circuit; Described LLC resonant converter, high frequency transformer, the second current rectifying and wave filtering circuit, heating load and power output end are linked in sequence; Wherein,

Described high frequency transformer converts voltage and isolates; Described second current rectifying and wave filtering circuit carries out the direct current of stable output after rectification and filtering to the high-frequency alternating current that high frequency transformer exports.