CN204615670U - Tri-level inversion welder circuit - Google Patents

Abstract

The utility model provides a kind of tri-level inversion welder circuit, comprising: power supply rectification filter circuit, three level translation circuit and inversion unit circuit; Three level translation circuit comprises IGBT pipe Q5, Q6, Q7 and Q8; The collector electrode of IGBT pipe Q5 connects the positive output end of power supply rectification filter circuit, and emitter connects the collector electrode of IGBT pipe Q6; The emitter of IGBT pipe Q6 connects the collector electrode of Q7, and the emitter of IGBT pipe Q7 connects the collector electrode of Q8; The emitter of IGBT pipe Q8 connects the negative output terminal of power supply rectification filter circuit; The emitter of IGBT pipe Q5 meets the first input end A of inversion unit circuit; The emitter of IGBT pipe Q7 meets the second input B of inversion unit circuit; The emitter of IGBT pipe Q6 connects the zero level node in power supply rectification filter circuit; The gate pole of IGBT pipe Q5, Q6, Q7 and Q8 connects Control timing sequence signal.The utility model can improve power supply reliability.

Description

Tri-level inversion welder circuit

Technical field

The utility model relates to inverter type welder, and some of especially a kind of inverter type welder three phase mains input circuit are improved.

Background technology

General inverter type welder three phase mains input circuit is all that three-phase electricity is directly added to inversion unit circuit after rectifying and wave-filtering, this circuit mode is simple and practical is belong to classical circuit design, this circuit applies very mature and reliable (as civil electric appliance) at below AC220V voltage, at the equipment (inversion welding machine of AC380V commercial power, plasma cutting machine, spraying source, Laser Power Devices, high power switching power supply etc.) after rectifying and wave-filtering, voltage can reach more than DC540V, so just higher to the requirement of withstand voltage of rear stage inversion unit circuit devcie, the operating frequency that these power supplys are general is all at more than 20KHz, what have reaches 100KHz, the switching loss of device is more much bigger than low-voltage device, the cost of device and spoilage are also higher, different impacts is also produced on the steady operation of various power supply.

Summary of the invention

For the deficiencies in the prior art, the utility model provides a kind of tri-level inversion welder circuit, solves the problem that in prior art, the requirement of inversion unit circuit devcie is high, can improve power supply reliability.The technical solution adopted in the utility model is:

A kind of tri-level inversion welder circuit, comprising: power supply rectification filter circuit, three level translation circuit and inversion unit circuit;

Three level translation circuit comprises IGBT pipe Q5, Q6, Q7 and Q8; The collector electrode of IGBT pipe Q5 connects the positive output end of power supply rectification filter circuit, and emitter connects the collector electrode of IGBT pipe Q6; The emitter of IGBT pipe Q6 connects the collector electrode of Q7, and the emitter of IGBT pipe Q7 connects the collector electrode of Q8; The emitter of IGBT pipe Q8 connects the negative output terminal of power supply rectification filter circuit; The emitter of IGBT pipe Q5 meets the first input end A of inversion unit circuit; The emitter of IGBT pipe Q7 meets the second input B of inversion unit circuit; The emitter of IGBT pipe Q6 connects the zero level node in power supply rectification filter circuit; The gate pole of IGBT pipe Q5, Q6, Q7 and Q8 connects Control timing sequence signal.

Further,

Power supply rectification filter circuit comprises three-phase commutation bridge Z1, electric capacity C1 and C2, resistance R1 and R2; The input termination three-phase alternating current of three-phase commutation bridge Z1; Between the positive output end that the branch road after electric capacity C1 and C2 connects is connected to three-phase commutation bridge Z1 and negative output terminal, between the positive output end that the branch road after resistance R1 and R2 connects is connected to three-phase commutation bridge Z1 and negative output terminal; The node that the node that electric capacity C1 with C2 is connected is connected with resistance R1 with R2 is connected, and as the zero level node in power supply rectification filter circuit.

The utility model has the advantage of: the utility model can make inverter type welder work more reliable and more stable, also reduce the requirement of withstand voltage of power device in inversion unit circuit, withstand voltage lower power tube can be selected, the volume that operating frequency reduces welding machine further can be improved simultaneously.

Accompanying drawing explanation

Fig. 1 is existing inverter type welder electrical schematic diagram.

Fig. 2 is inverter type welder electrical schematic diagram of the present utility model.

Embodiment

Below in conjunction with concrete drawings and Examples, the utility model is described in further detail.

The electric principle of existing inverter type welder is see Fig. 1, and input three-phase electricity is directly added to inversion unit circuit after rectifying and wave-filtering, and the voltage at inversion unit circuit two ends is DC540V; Higher to the requirement of withstand voltage of inversion unit circuit devcie.

The technical solution of the utility model is, the translation circuit that one is changed into DC540V+270V/0V/-270V three level is increased between original power supply rectification filter circuit and inversion unit circuit, the inversion unit circuit of rear stage only bears 1/2 busbar voltage (270V), therefore can select withstand voltage lower power tube, the volume that operating frequency reduces welding machine further can be improved simultaneously.

Circuit after improvement is shown in Fig. 2, adds three level translation circuit after power supply rectification filter circuit, is then being added to the inversion unit circuit of inverter type welder.

The tri-level inversion welder circuit that the utility model proposes comprises: power supply rectification filter circuit, three level translation circuit and inversion unit circuit; Also comprise other output transformer of the prior art, output current rectifying and wave filtering circuit etc.

Three level translation circuit comprises IGBT pipe Q5, Q6, Q7 and Q8; The collector electrode of IGBT pipe Q5 connects the positive output end of power supply rectification filter circuit, and emitter connects the collector electrode of IGBT pipe Q6; The emitter of IGBT pipe Q6 connects the collector electrode of Q7, and the emitter of IGBT pipe Q7 connects the collector electrode of Q8; The emitter of IGBT pipe Q8 connects the negative output terminal of power supply rectification filter circuit; The emitter of IGBT pipe Q5 meets the first input end A of inversion unit circuit; The emitter of IGBT pipe Q7 meets the second input B of inversion unit circuit; The emitter of IGBT pipe Q6 connects the zero level node in power supply rectification filter circuit; The gate pole of IGBT pipe Q5, Q6, Q7 and Q8 connects Control timing sequence signal.

Above-mentioned IGBT pipe Q5, Q6, Q7 and Q8 adopt Power Insulated Gate Bipolar transistor npn npn.

Power supply rectification filter circuit comprises three-phase commutation bridge Z1, electric capacity C1 and C2, resistance R1 and R2; The input termination three-phase alternating current of three-phase commutation bridge Z1; Between the positive output end that the branch road after electric capacity C1 and C2 connects is connected to three-phase commutation bridge Z1 and negative output terminal, between the positive output end that the branch road after resistance R1 and R2 connects is connected to three-phase commutation bridge Z1 and negative output terminal; The node that the node that electric capacity C1 with C2 is connected is connected with resistance R1 with R2 is connected, and as the zero level node in power supply rectification filter circuit.

Electric capacity Cl, C2 and R1, R2 provide 2 identical direct voltages (+270V and-270V) for circuit.When simultaneously conducting Q6 and Q8 turns off Q5 and Q7 simultaneously, electric current is from C1(+270V) → Q5 → inversion unit circuit A end → inversion unit circuit B end → Q7 → C1 (0V) is+270V at the input A of inversion unit circuit and B terminal voltage like this.When simultaneously conducting Q5 and Q7 turns off Q6 and Q8 simultaneously, electric current is from C2(0V) → Q6 → inversion unit circuit A end → inversion unit circuit B end → Q8 → C2 (-270V) is+270V at the input A of inversion unit circuit and B terminal voltage like this; Voltage between input A and B of such inversion unit circuit is always 1/2 of supply voltage.

Claims (2)

1. a tri-level inversion welder circuit, is characterized in that, comprising: power supply rectification filter circuit, three level translation circuit and inversion unit circuit;

Three level translation circuit comprises IGBT pipe Q5, Q6, Q7 and Q8; The collector electrode of IGBT pipe Q5 connects the positive output end of power supply rectification filter circuit, and emitter connects the collector electrode of IGBT pipe Q6; The emitter of IGBT pipe Q6 connects the collector electrode of Q7, and the emitter of IGBT pipe Q7 connects the collector electrode of Q8; The emitter of IGBT pipe Q8 connects the negative output terminal of power supply rectification filter circuit; The emitter of IGBT pipe Q5 meets the first input end A of inversion unit circuit; The emitter of IGBT pipe Q7 meets the second input B of inversion unit circuit; The emitter of IGBT pipe Q6 connects the zero level node in power supply rectification filter circuit; The gate pole of IGBT pipe Q5, Q6, Q7 and Q8 connects Control timing sequence signal.

2. tri-level inversion welder circuit as claimed in claim 1, is characterized in that:

Power supply rectification filter circuit comprises three-phase commutation bridge Z1, electric capacity C1 and C2, resistance R1 and R2; The input termination three-phase alternating current of three-phase commutation bridge Z1; Between the positive output end that the branch road after electric capacity C1 and C2 connects is connected to three-phase commutation bridge Z1 and negative output terminal, between the positive output end that the branch road after resistance R1 and R2 connects is connected to three-phase commutation bridge Z1 and negative output terminal; The node that the node that electric capacity C1 with C2 is connected is connected with resistance R1 with R2 is connected, and as the zero level node in power supply rectification filter circuit.