CN205430082U - Contravariant welding machine electrical power generating system with power factor correction function - Google Patents

Abstract

The utility model discloses a contravariant welding machine electrical power generating system with power factor correction function, include the power factor correction circuit based on the BOOST chopper, the power factor correction circuit is including the EMI filter circuit, diode, inverter circuit and the rectification filter circuit that establish ties in proper order, it has the MOS switch tube to connect in parallel on the power factor correction circuit, diode output linked switch converter circuit, the switch converter circuit includes reference voltage, voltage error amplifier, current error amplifier, multiplier, PWM modulator and voltage sampler and current sample ware, beneficial effect does: use the contravariant welding machine power that has a power factor correction function of above -mentioned scheme, can reduce to input harmonic current, improve the power factor of contravariant welding machine, reduce the pollution to the electric wire netting.

Description

Inverter welding machine power supply system with power factor correction function

【Technical field】

The utility model relates to in particular an inverter welding machine power supply system with power factor correction function.

【Background technique】

Welding power supply is an important equipment for welding. With the development of power electronics technology, the technology development of inverter welding machine is more mature and its application is more extensive. Since the inverter welding machine is manufactured based on power switching elements, these elements are typical nonlinear elements, resulting in a very low power factor of the system. The power factor has a great impact on the operating environment of the power grid, especially the high-order harmonic current is very harmful to the power grid, and even interferes with the normal operation of surrounding electrical equipment. Using PWM sorting circuit instead of traditional diode rectification can reduce the electrical pollution caused by welding equipment to the power grid, but the cost is very high, and it is not suitable for popularization and application in low-power occasions.

To sum up, the welding power source in the prior art has the following defects: its power factor will pollute the power grid during operation, thereby affecting the normal operation of peripheral equipment.

【Content of utility model】

The utility model provides a novel inverter welding machine power supply system with a power factor correction function to solve the problems of the prior art.

The technical scheme of the utility model is as follows: the inverter welding machine power supply system with power factor correction function includes a power factor correction circuit based on a BOOST chopper; the power factor correction circuit includes an EMI filter circuit, a diode, an inverter Transformer circuit and rectification filter circuit, the output end of the rectification filter circuit is connected to the load; the power factor correction circuit is connected with a MOS switch tube in parallel; the output end of the diode is connected to the switching converter circuit; the switching converter circuit includes a reference voltage, a voltage Error amplifier, current error amplifier, multiplier, PWM modulator, voltage sampler and current sampler; the load output terminal is sequentially output voltage detector, voltage error amplifier, multiplier and voltage sampler to the diode output terminal in series, so The output terminal of the diode is connected to the current sampler, the current error amplifier, the PWM modulator and the driver in sequence, the output terminal of the driver is connected to the gate of the MOS switch tube; the output terminal of the multiplier is connected to the input terminal of the current error amplifier.

In a preferred solution, the inverter circuit is a dual-tube reset single-ended forward inverter circuit, which includes a main switching element IGBT tube, and the IGBT tube includes a diode V1, a diode V2, a diode V3, and a diode V4, wherein the diode V1 and the diode V2 are connected in parallel, Diode V3 is connected in parallel with diode V4.

In a preferred solution, an RCD snubber circuit is connected in parallel between the collector and the emitter of the IGBT tube.

Preferably, the power factor correction circuit includes an ICE2PCS05 control chip, the ICE2PCS05 control chip has 8 pins, pin 1 is the chip ground terminal, pin 2 is the current control loop compensation terminal, grounded through a capacitor, and pin 3 is the current The detection input terminal is connected to the rectified output current through a resistor. Pin 4 is the switching frequency signal terminal, which is grounded through a resistor. Pin 5 is the voltage control loop compensation terminal, which is grounded through the voltage compensation circuit. Pin 6 is the output voltage detection feedback In the input terminal, pin 7 is the power supply input of the chip, and pin 8 is the gate output terminal of the chip, which is connected to the gate of the switch tube.

The beneficial effects of the utility model are: the use of the inverter welding machine power supply with power factor correction function of the above scheme can reduce the input harmonic current, improve the power factor of the inverter welding machine, and reduce the pollution to the power grid.

【Description of drawings】

Fig. 1 is the circuit topology diagram of the utility model inverter welding power supply;

Fig. 2 is the power factor correction circuit diagram based on the BOOST chopper of the utility model;

Fig. 3 is the circuit diagram of double-tube reset single-ended positive excitation inverter of the present invention;

Fig. 4 is a power factor correction circuit diagram composed of ICE2PCS05 of the utility model.

【detailed description】

The following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention can be implemented. The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only Refer to attached drawings for directions. Therefore, the used directional terms are used to illustrate and understand the present invention, but not to limit the present invention. In the figures, structurally similar units are denoted by the same reference numerals.

The utility model provides an inverter welding machine power supply system with a power factor correction function, and the system includes a power factor correction circuit based on a BOOST chopper;

Referring to Fig. 1, the power factor correction circuit includes an EMI filter circuit, a diode, an inverter circuit and a rectification filter circuit connected in series in sequence, and the output end of the rectification filter circuit is connected to a load; the power factor correction circuit is connected in parallel with a MOS switch tube ; The output end of the diode is connected to the switching converter circuit; this circuit shows the overall composition of the welding machine power supply, the AC grid voltage is rectified by diodes and power factor correction links to obtain a DC signal, and then provided to the welding machine through inverter and secondary rectification machine load.

Referring to Fig. 2, the power factor correction circuit diagram based on BOOST chopper is provided, and this figure is mainly used for explaining the working principle of PFC; Described switching converter circuit comprises reference voltage, voltage error amplifier, current error amplifier, multiplier, A PWM modulator, a voltage sampler and a current sampler; the load output terminal sequentially outputs a voltage detector, a voltage error amplifier, a multiplier and a voltage sampler to the diode output terminal in series, and the diode output terminal is sequentially connected to the current sampler, A current error amplifier, a PWM modulator and a driver, the output of the driver is connected to the gate of the MOS switching tube; the output of the multiplier is connected to the input of the current error amplifier; the output DC voltage of the main circuit is compared with the reference voltage, and the deviation Send it into the voltage error amplifier, the output of the voltage error amplifier and the rectified voltage are added to the multiplier together to obtain the current reference signal, which is compared with the input rectification circuit, and then sent into the current error amplifier to obtain the PWM driving signal of the switch tube to control the switching tube. on and off.

Refer to Figure 3, which shows the circuit diagram of double-tube reset and single-ended forward inverter; this circuit is the latter part of the power system, and its main function is to invert the DC power into AC power, and then provide it to the welder load through secondary rectification; diode V1 , diode V2, diode V3, and diode V4 are IGBT tubes. In practical applications, it is best to choose IGBT tubes of the same batch and type. The specific method of IGBT tube parameter selection is given below. Taking the input grid voltage of 220V as an example, after rectification and filtering, the peak value of the DC output voltage is calculated as:

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; a</span>}$

Considering k _u =1.1 voltage fluctuation coefficient and margin coefficient a=1.1, the peak voltage can reach 376V. Since the IGBT bears a larger voltage when it is turned off, the voltage borne by the IGBT can be calculated as follows:

U _ceps ＝(U _d ×k _u +U _l )×a

The overvoltage coefficient is taken as k _u =1.15, the peak voltage is taken as U _l =150V, and the margin coefficient a=1.1 is taken into consideration, the maximum turn-off peak voltage is 650V, and an IGBT of 1000V can be selected in actual use. Calculated according to the rated output current of 200A, the average current flowing through the IGBT is about 40A. Considering the overload capacity factor and surge current of 1.5 times, an IGBT with a rated current of 100A can be selected.

See Figure 4, which shows the power factor correction circuit diagram composed of ICE2PCS05; ICE2PCS05 control chip has 8 pins, pin 1 is the chip ground terminal, pin 2 is the compensation terminal of the current control loop, grounded through a capacitor, pin 3 It is the current detection input terminal, connected to the rectified output current through the resistor, pin 4 is the switching frequency signal terminal, grounded through the resistor, pin 5 is the voltage control loop compensation terminal, grounded through the voltage compensation circuit, and pin 6 is the output voltage Detection feedback input terminal, pin 7 is the chip power supply input, pin 8 is the chip gate output terminal, connected to the switch gate; this circuit provides the input rectification filter and PFC correction part, and the input side of the circuit is carried out through the fuse Overcurrent protection, using varistors for overvoltage protection, using resistors to reduce the inrush current at startup; the front-end filter is mainly used to filter out radio frequency interference signals; the rectifier bridge adopts diode full-bridge rectification; The control chip can be realized by simply building the peripheral circuit.

Claims (4)

1. there is the contravariant welding machine electric power system of power factor emendation function, it is characterised in that include circuit of power factor correction based on BOOST chopper；Described circuit of power factor correction includes EMI filter circuit, diode, inverter circuit and the current rectifying and wave filtering circuit being sequentially connected in series, and described rectification filter circuit output end connects load；MOS switch pipe it is parallel with on described circuit of power factor correction；Diode output connecting valve converter circuit；Described Switching Converter Topologies includes reference voltage, voltage error amplifier, current error amplifier, multiplier, PWM modulator and voltage sample device and current sampler；Described load outputs is sequentially connected in series output voltage detector, voltage error amplifier, multiplier and voltage sample device to diode output, described diode output is sequentially connected with current sampler, current error amplifier, PWM modulator and driving, and described drive output connects the gate pole of MOS switch pipe；Described multiplier outputs connects current error amplifier input.

The contravariant welding machine electric power system with power factor emendation function the most according to claim 1, it is characterized in that, described inverter circuit is two-tube reset single-end ortho-exciting inverter circuit, manage including main switch element IGBT, IGBT pipe includes diode V1, diode V2, diode V3 and diode V4, wherein diode V1 is in parallel with diode V2, and diode V3 is in parallel with diode V4.

The contravariant welding machine electric power system with power factor emendation function the most according to claim 1, it is characterised in that between colelctor electrode and the emitter stage of described IGBT pipe, RCD in parallel absorbs buffer circuit.

The contravariant welding machine electric power system with power factor emendation function the most according to claim 1, it is characterized in that, described circuit of power factor correction includes ICE2PCS05 control chip, ICE2PCS05 control chip has 8 pins, pin 1 is chip ground end, pin 2 compensates end for current regulator, pass through capacity earth, pin 3 is current sense input, the electric current of rectification output is accessed by resistance, pin 4 is switch frequency signal end, pass through resistance eutral grounding, pin 5 compensates end for voltage control loop, by voltage compensation loop ground connection, pin 6 detects feedback input end for output voltage, pin 7 inputs for chip power supply, pin 8 is chip gate pole outfan, it is connected to switching tube gate pole.