High-low voltage alternate charging type energy storage resistance welding machine system circuit

Abstract

The utility model discloses a high-low voltage alternate charging type energy storage resistance welding machine system circuit which comprises a full-bridge half-control rectification module, a high-low voltage alternate charging control module, an energy storage capacitor C, a discharging control module and a welding transformer. The full-bridge half-control rectification module is electrically connected with the high-low voltage alternate charging control module, a filter capacitor C1 is connected between a loop formed by the full-bridge half-control rectification module and the high-low voltage alternate charging control module, a charging loop is formed between the high-low voltage alternate charging control module and the energy storage capacitor C, and an inductance element L is connected to the charging loop. The energy storage electric capacitor C is connected with the welding transformer, and a discharging loop is formed between the energy storage electric capacitor C and the welding transformer and connected with a discharging control module. During charging, low-voltage and high-voltage alternate charging can be realized, the polarity of the charging circuit is not reversed, and the requirement on voltage resistance of components is low.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage resistance welding machine technology, specifically relating to a high and low voltage alternating charging type energy storage resistance welding machine system circuit. Background Technology

[0002] In traditional energy storage welding circuits, the capacitor can often only support a single or limited charging voltage range, thus failing to adapt to diverse welding needs and limiting the flexibility and application range of the welding process. Welding quality largely depends on the energy released during welding. If the energy storage capacitor cannot be charged at high or low voltage as needed, insufficient energy may result in failure to penetrate thicker materials and form a strong weld, or excessive energy may lead to spatter, overheating, or even damage to the welding material. Utility Model Content

[0003] To address the aforementioned problems, this utility model provides a high-low voltage alternating charging type energy storage resistance welding machine system circuit, including a full-bridge semi-controlled rectifier module, a high-low voltage alternating charging control module, an energy storage capacitor C, a discharge control module, and a welding transformer. The full-bridge semi-controlled rectifier module is electrically connected to the high-low voltage alternating charging control module, and a filter capacitor C1 is connected between the two circuits. A charging circuit is formed between the high-low voltage alternating charging control module and the energy storage capacitor C, and an inductor L is connected to the charging circuit. The energy storage capacitor C is connected to the welding transformer, and a discharge circuit is formed between them, with the discharge control module connected to the discharge circuit. The high-low voltage alternating charging control module includes IGBT modules Q1 and Q2. IGBT modules Q3 and Q4 are configured such that one end of the inductor L is electrically connected to the emitter of IGBT module Q1 and the collector of IGBT module Q2, and the other end of the inductor L is electrically connected to the emitter of IGBT module Q3 and the collector of IGBT module Q4. The collector of IGBT module Q1 is electrically connected to the anode of the filter capacitor C1, the emitter of IGBT module Q1 is electrically connected to the collector of IGBT module Q2, the emitter of IGBT module Q2 is electrically connected to the cathode of the filter capacitor C1 and the emitter of IGBT module Q4, the collector of IGBT module Q3 is electrically connected to the anode of the energy storage capacitor C, the emitter of IGBT module Q3 is electrically connected to the collector of IGBT module Q4, and the emitter of IGBT module Q4 is electrically connected to the cathode of the energy storage capacitor C.

[0004] Preferably, the input terminal of the inductor L is connected to a charging current sensor.

[0005] Preferably, a primary current sensor is connected to the input terminal of the welding transformer, and a secondary current sensor is connected to the output terminal of the welding transformer.

[0006] Preferably, the discharge control module includes an IGBT module Q5 and a diode D8. The collector of the IGBT module Q5 is electrically connected to the anode of the energy storage capacitor C. The emitter of the IGBT module Q5 is electrically connected to the cathode of the diode D8 and the upper end of the input of the welding transformer. The anode of the diode D8 is electrically connected to the cathode of the energy storage capacitor C and the lower end of the input of the welding transformer.

[0007] Preferably, the discharge control module includes IGBT modules Q6, Q7, Q8, and Q9. The collector of IGBT module Q6 is electrically connected to the anode of the energy storage capacitor C and the collector of IGBT module Q8. The emitter of IGBT module Q6 is electrically connected to the collector of IGBT module Q7 and the upper end of the welding transformer input. The emitter of IGBT module Q8 is electrically connected to the lower end of the welding transformer input and the collector of IGBT module Q9. The emitters of IGBT modules Q7 and Q9 are electrically connected to the cathode of the energy storage capacitor C.

[0008] Preferably, the full-bridge semi-controlled rectifier module includes thyristors D2, D3, and D4, as well as diodes D5, D6, and D7. The anodes of thyristors D2, D3, and D4 are electrically connected to the cathodes of diodes D5, D6, and D7, respectively. The anodes of diodes D5, D6, and D7 are electrically connected to the cathode of filter capacitor C1. The cathodes of thyristors D2, D3, and D4 are electrically connected to the anode of filter capacitor C1.

[0009] Preferably, the thyristors D2, D3, and D4 are electrically connected to a three-phase power supply, one phase of the three-phase power supply is electrically connected to a charging diode D1, the charging diode is electrically connected to a charging resistor R1, and the other end of the charging resistor R1 is electrically connected to the thyristor D2.

[0010] The advantages of this utility model are:

[0011] 1. This solution utilizes a high-low voltage alternating charging control module to precisely control the charging voltage and process. This ensures that the energy released during welding is just right, preventing insufficient energy from penetrating thicker materials and avoiding excessive energy that could cause spatter, overheating, or even damage to the welding material, thus significantly improving welding quality. Furthermore, because the charging circuit does not reverse polarity, the voltage withstand requirements for components are relatively low, reducing system complexity and cost.

[0012] 2. In this design, the inductor L can be used to recover and store energy. When the charging current stops, the inductor L will release the stored energy to continue charging the capacitor, thus avoiding waste of this energy.

[0013] 3. This solution allows for control of the current drop rate during discharge, adapting to different welding requirements. Furthermore, by controlling the switches of the two IGBT modules, the direction of the welding current can be switched at will, accommodating different welding process needs. Attached Figure Description

[0014] Figure 1 This is a circuit diagram of Embodiment 1 of the present invention.

[0015] Figure 2 This is a circuit diagram of Embodiment 2 of the present invention.

[0016] In the diagram: 1 Full-bridge semi-controlled rectifier module, 2 High and low voltage alternating charging control module, 3 Discharge control module, 4 Welding transformer, 5 Charging current sensor, 6 Primary current sensor, 7 Secondary current sensor. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Example 1

[0018] like Figure 1 As shown, a high-low voltage alternating charging type energy storage resistance welding machine system circuit includes a full-bridge semi-controlled rectifier module 1, a high-low voltage alternating charging control module 2, an energy storage capacitor C, a discharge control module 3, and a welding transformer 4. The full-bridge semi-controlled rectifier module 1 and the high-low voltage alternating charging control module 2 are electrically connected, and a filter capacitor C1 is connected between the two circuits. A charging circuit is formed between the high-low voltage alternating charging control module 2 and the energy storage capacitor C. An inductor L is connected to the charging circuit. The inductor L is a charging filter inductor. The energy storage capacitor C and the welding transformer 4 are electrically connected, and a discharge circuit is formed between the two. The discharge control module 3 is connected to the discharge circuit.

[0019] The full-bridge semi-controlled rectifier module 1 includes thyristors D2, D3, and D4, as well as diodes D5, D6, and D7. The anodes of thyristors D2, D3, and D4 are electrically connected to the cathodes of diodes D5, D6, and D7, respectively. The anodes of diodes D5, D6, and D7 are electrically connected to the cathode of filter capacitor C1. The cathodes of thyristors D2, D3, and D4 are electrically connected to the anode of filter capacitor C1.

[0020] By triggering the full-bridge semi-controlled rectifier module 1, when the voltage reaches approximately 500V, thyristors D2, D3, and D4 are turned on, and the voltage of filter capacitor C1 reaches its maximum value. At this point, the circuit forms a stable DC power supply to charge the energy storage capacitor C. The current first passes through filter capacitor C1. Filter capacitor C1 filters out high-frequency noise, smooths the DC voltage, and stabilizes the voltage waveform to ensure normal circuit operation. A resistor R2 is connected in parallel with filter capacitor C1 to achieve better filtering effect and stability.

[0021] The high-low voltage alternating charging control module 2 includes IGBT modules Q1, Q2, Q3, and Q4. One end of the inductor L is electrically connected to the emitter of IGBT module Q1 and the collector of IGBT module Q2. The other end of the inductor L is electrically connected to the emitter of IGBT module Q3 and the collector of IGBT module Q4. The collector of IGBT module Q1 is electrically connected to the anode of filter capacitor C1. The emitter of IGBT module Q1 is electrically connected to the collector of IGBT module Q2. The emitter of IGBT module Q2 is electrically connected to the cathode of filter capacitor C1 and the emitter of IGBT module Q4. The collector of IGBT module Q3 is electrically connected to the anode of energy storage capacitor C. The emitter of IGBT module Q3 is electrically connected to the collector of IGBT module Q4. The emitter of IGBT module Q4 is electrically connected to the cathode of energy storage capacitor C. A charging current sensor 5 is also connected to the input terminal of the inductor L.

[0022] The energy for each welding operation is drawn from the energy stored in the energy storage capacitor C. When charging the energy storage capacitor C, if its voltage is lower than that of the filter capacitor C1 (a low-voltage charging state), the pulse width of the IGBT module Q1 is adjusted. Controlled by the current feedback from the charging current sensor 5, the charging current flows through the inductor L, then through the diode in IGBT module Q3, and finally forms a freewheeling circuit with the diode in IGBT module Q2. When IGBT module Q1 is turned on, current flows into the energy storage capacitor C through the inductor L. When IGBT module Q1 is turned off, due to the presence of the charging filter inductor, it acts as a power source. The charging filter inductor, energy storage capacitor C, IGBT module Q2, and IGBT module Q3 form a current loop, continuing to charge the energy storage capacitor C. Charging stops when the voltage of the energy storage capacitor C reaches the predetermined target voltage. The charging filter inductor can be used to recover and store energy. When the charging current stops, the charging filter inductor releases the stored energy to continue charging the energy storage capacitor C, thus avoiding energy waste.

[0023] When the voltage of the energy storage capacitor C is higher than the voltage of the filter capacitor C1, it is in a high-voltage charging state. By controlling the pulse width of IGBT modules Q1 and Q4, when IGBT module Q4 is turned on, the current flows from the positive terminal of the filter capacitor C1, through IGBT module Q1, inductor L, and IGBT module Q4 to the negative terminal of the energy storage capacitor C. When IGBT module Q4 is turned off, the current in inductor L cannot change abruptly. The energy stored in inductor L will flow through IGBT module Q3 and then to the energy storage capacitor C, making the voltage of the energy storage capacitor C higher than the voltage of the filter capacitor C1. The above charging circuit does not reverse polarity and has low voltage withstand requirements for components.

[0024] The anodes of thyristors D2, D3, and D4 are electrically connected to the three-phase power supply. One phase of the three-phase power supply is electrically connected to the anode of charging diode D1. The cathode of charging diode D1 is electrically connected to one end of charging resistor R1, and the other end of charging resistor R1 is electrically connected to the cathode of diode D2. Charging diode D1 and charging resistor R1 form a small-current charging circuit, used to charge filter capacitor C1 with a small current.

[0025] An energy storage capacitor C is electrically connected to a welding transformer 4, forming a discharge circuit between the energy storage capacitor C and the welding transformer 4. A discharge control module 3 is connected to the discharge circuit. In this embodiment, the discharge control module 3 includes an IGBT module Q5 and a diode D8. The collector of the IGBT module Q5 is electrically connected to the anode of the energy storage capacitor C, the emitter of the IGBT module Q5 is electrically connected to the cathode of the diode D8 and the upper end of the input of the welding transformer 4, and the anode of the diode D8 is electrically connected to the cathode of the energy storage capacitor C and the lower end of the input of the welding transformer 4. After the IGBT module Q5 is turned off, the diode D8 can maintain the continuity of the current in the discharge circuit, preventing voltage fluctuations and electromagnetic interference caused by sudden current interruption. This helps to maintain the stability and reliability of the welding process. A primary current sensor is connected to the input line of the welding transformer 4 to collect the primary welding current, and a secondary current sensor is connected to the output of the welding transformer 4 to detect the secondary welding current.

[0026] This embodiment uses a unidirectional discharge method, with discharge control performed by a single IGBT module. Although it can only control unidirectional current, it uses only one IGBT module, resulting in low manufacturing costs. Example 2

[0027] like Figure 2As shown, this embodiment shares the same parts as Embodiment 1. The difference between this embodiment and Embodiment 1 lies in the discharge control module 3. In this embodiment, the discharge control module 3 includes IGBT modules Q6, Q7, Q8, and Q9. The collector of IGBT module Q6 is electrically connected to the anode of the energy storage capacitor C and the collector of IGBT module Q8. The emitter of IGBT module Q6 is electrically connected to the collector of IGBT module Q7 and the upper end of the input of the welding transformer 4. The emitter of IGBT module Q8 is electrically connected to the lower end of the input of the welding transformer 4 and the collector of IGBT module Q9. The emitters of IGBT modules Q7 and Q9 are electrically connected to the cathode of the energy storage capacitor C. A primary current sensor is connected to the input line of the welding transformer to collect the primary welding current, and a secondary current sensor is connected to the output of the welding transformer to detect the secondary welding current.

[0028] In this embodiment, four IGBT modules are used to discharge alternately. The advantage of alternating discharge is that it avoids transformer magnetization. During discharge, discharge IGBT Q2 and discharge IGBT Q5 are turned on simultaneously, with the current flowing in one direction. Discharge IGBT Q3 and discharge IGBT Q4 are turned on simultaneously, with the current flowing in another direction. Only one set is turned on for each welding operation. By controlling the turn-off of the IGBT modules, the current drop rate can be controlled to adapt to different welding requirements. Furthermore, by controlling the switching of the two sets of IGBT modules, the direction of the welding current can be switched arbitrarily to adapt to different welding process requirements.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-low voltage alternating charging type energy storage resistance welding machine system circuit, characterized in that: The system includes a full-bridge semi-controlled rectifier module (1), a high-low voltage alternating charging control module (2), an energy storage capacitor C, a discharge control module (3), and a welding transformer (4). The full-bridge semi-controlled rectifier module (1) and the high-low voltage alternating charging control module (2) are electrically connected, and a filter capacitor C1 is connected between the two. A charging circuit is formed between the high-low voltage alternating charging control module (2) and the energy storage capacitor C. An inductor L is connected to the charging circuit. The energy storage capacitor C is connected to the welding transformer (4), and a discharge circuit is formed between them. A discharge control module (3) is connected to the discharge circuit. The high-low voltage alternating charging control module (2) includes an IGBT module Q1 and an IGBT module Q2. IGBT modules Q3 and Q4 are configured such that one end of the inductor L is electrically connected to the emitter of IGBT module Q1 and the collector of IGBT module Q2, and the other end of the inductor L is electrically connected to the emitter of IGBT module Q3 and the collector of IGBT module Q4. The collector of IGBT module Q1 is electrically connected to the anode of the filter capacitor C1, the emitter of IGBT module Q1 is electrically connected to the collector of IGBT module Q2, the emitter of IGBT module Q2 is electrically connected to the cathode of the filter capacitor C1 and the emitter of IGBT module Q4, the collector of IGBT module Q3 is electrically connected to the anode of the energy storage capacitor C, the emitter of IGBT module Q3 is electrically connected to the collector of IGBT module Q4, and the emitter of IGBT module Q4 is electrically connected to the cathode of the energy storage capacitor C.

2. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 1, characterized in that: The input terminal of the inductor L is connected to a charging current sensor (5).

3. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 2, characterized in that: The input terminal of the welding transformer (4) is connected to a primary current sensor (6), and the output terminal of the welding transformer (4) is connected to a secondary current sensor (7).

4. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 3, characterized in that: The discharge control module (3) includes an IGBT module Q5 and a diode D8. The collector of the IGBT module Q5 is electrically connected to the anode of the energy storage capacitor C. The emitter of the IGBT module Q5 is electrically connected to the cathode of the diode D8 and the upper end of the input of the welding transformer (4). The anode of the diode D8 is electrically connected to the cathode of the energy storage capacitor C and the lower end of the input of the welding transformer (4).

5. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 3, characterized in that: The discharge control module (3) includes IGBT module Q6, IGBT module Q7, IGBT module Q8, and IGBT module Q9. The collector of IGBT module Q6 is electrically connected to the anode of the energy storage capacitor C and the collector of IGBT module Q8. The emitter of IGBT module Q6 is electrically connected to the collector of IGBT module Q7 and the upper end of the input of the welding transformer (4). The emitter of IGBT module Q8 is electrically connected to the lower end of the input of the welding transformer (4) and the collector of IGBT module Q9. The emitters of IGBT modules Q7 and Q9 are electrically connected to the cathode of the energy storage capacitor C.

6. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 4 or claim 5, characterized in that: The full-bridge semi-controlled rectifier module (1) includes thyristors D2, D3, and D4, as well as diodes D5, D6, and D7. The anodes of thyristors D2, D3, and D4 are electrically connected to the cathodes of diodes D5, D6, and D7, respectively. The anodes of diodes D5, D6, and D7 are electrically connected to the cathode of filter capacitor C1. The cathodes of thyristors D2, D3, and D4 are electrically connected to the anode of filter capacitor C1.

7. The high-low voltage alternating charging type energy storage resistance welding machine system circuit according to claim 6, characterized in that: The thyristors D2, D3, and D4 are electrically connected to a three-phase power supply. One phase of the three-phase power supply is electrically connected to a charging diode D1. The charging diode is electrically connected to a charging resistor R1. The other end of the charging resistor R1 is electrically connected to the thyristor D2.

Images