A high-voltage direct-current power supply for axial-flow CO2 laser

Abstract

The application discloses a high-voltage direct-current power supply for an axial fast-flow CO2 laser, and relates to the technical field of high-voltage direct-current power supplies, comprising a three-phase rectification module, a soft-start filtering module, a phase-shift full-bridge inversion module, a high-frequency voltage-boosting module, a high-voltage rectification output module, a setting signal input module, a laser energy feedback module, a phase shift control module, a primary-side current detection module and a protection module; three-phase alternating current is rectified, filtered, phase-shift inverter, isolated boosted and high-voltage rectified to form a high-voltage direct-current output; the phase shift control module adjusts a phase shift angle according to the deviation of a power setting signal and a laser energy feedback signal; and the primary-side current detection module triggers the protection module to shut off a driving output when the current reaches a preset condition. Through laser energy closed-loop regulation, primary-side current rapid protection, high-frequency voltage-boosting and water-cooling heat dissipation, the output stability and response capability are improved, negative resistance discharge overshoot is inhibited, abnormal discharge risk is reduced, and the power supply efficiency, power density and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of high voltage DC power supply technology, specifically a high voltage DC power supply for axial fast-flow CO2 lasers. Background Technology

[0002] The resistivity of most ordinary high-voltage power supply loads is linear, with load parameters remaining constant over a long period without real-time fluctuations. High voltage accuracy is required, but there are no strict requirements on current, and the discharge mode is not a concern; the power supply is generally single-loop voltage control. In contrast, axial fast-current CO2 gas lasers operate in a glow discharge state, exhibiting negative resistance characteristics and thus being nonlinear loads.

[0003] Existing high-voltage DC power supplies for axial fast-current CO2 gas lasers have the following technical problems: First, the laser discharge tube requires an ignition voltage several times higher than the operating voltage to break down the gas inside the tube, resulting in high voltage requirements for the power supply during startup. Second, due to the gas insulation characteristics of the laser, its long discharge tube structure, high power output requirements, and high-speed airflow design, it has a rigid requirement for a high-voltage power supply. Third, the magnitude of the power supply current directly affects the output power of the laser, while the internal heat dissipation structure of the laser limits the upper limit of the output current, thus restricting power improvement. Finally, the negative resistance characteristics of the laser gas are prone to causing current avalanche, affecting the stability and safety of the power supply.

[0004] Ordinary high-voltage power supplies can no longer meet the power requirements of axial fast-flow CO2 gas lasers. Therefore, this special high-voltage power supply was developed to improve the output power and output stability of the laser. Summary of the Invention

[0005] Based on the shortcomings of the prior art described above, the purpose of this invention is to provide a high-voltage DC power supply for axial fast-flow CO2 lasers to solve the aforementioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-voltage DC power supply for a fast-flowing axial CO2 laser, comprising: a three-phase rectifier module, a soft-start filter module, a phase-shifting full-bridge inverter module, a high-frequency boost module, a high-voltage rectifier output module, a setting signal input module, a laser energy feedback module, a phase-shift control module, a primary-side current detection module, and a protection module; The three-phase rectifier module is used to receive three-phase AC input and form DC bus voltage; The soft-start filter module is connected between the three-phase rectifier module and the phase-shifted full-bridge inverter module, and is used to suppress and filter the DC bus voltage during startup. Phase-shifting full-bridge inverter modules are used to convert DC bus voltage into high-frequency AC voltage; The high-frequency boost module is connected to the phase-shifted full-bridge inverter module and is used to isolate and boost the high-frequency AC voltage. The high-voltage rectifier output module is connected to the high-frequency boost module to rectify the boosted high-frequency AC voltage into a high-voltage DC output for use in the discharge of the axial fast-current CO2 laser. The setting signal input module is used to receive power setting signals input from an external control terminal; The laser energy feedback module is used to receive feedback signals that reflect the output energy or output power of the axial fast-flow CO2 laser; The phase shift control module is connected to the setting signal input module, the laser energy feedback module, and the phase-shifted full-bridge inverter module respectively. It is used to adjust the phase shift angle of the phase-shifted full-bridge inverter module according to the deviation between the power setting signal and the feedback signal, so as to adjust the high voltage DC output. The primary current detection module is used to detect the current status on the primary side of the high-frequency boost module; The protection module is connected to the primary current detection module and the phase shift control module respectively, and is used to shut off the drive output of the phase-shifting full-bridge inverter module when the primary current reaches the preset protection condition.

[0007] The present invention is further configured such that the phase-shift control module includes a phase-shift full-bridge control chip, the phase-shift full-bridge control chip is provided with an error amplification input terminal, a current detection terminal and a multi-bridge arm drive output terminal, the error amplification input terminal includes an error amplification inverting input terminal and an error amplification non-inverting input terminal, the error amplification inverting input terminal is used to receive feedback signals, the error amplification non-inverting input terminal is used to receive power setting signals, and the multi-bridge arm drive output terminal respectively outputs drive control signals for controlling the switching devices of each bridge arm in the phase-shift full-bridge inverter module.

[0008] The present invention is further configured such that the laser energy feedback module includes a feedback voltage divider unit and a negative feedback processing unit. The feedback voltage divider unit includes voltage divider resistors connected in series for dividing the laser feedback signal and outputting a feedback sampling signal at the voltage divider node. The negative feedback processing unit includes an operational amplifier, an input resistor, and a feedback resistor. The input resistor is connected between the voltage divider node and the inverting input terminal of the operational amplifier. The feedback resistor is connected between the output terminal and the inverting input terminal of the operational amplifier. The non-inverting input terminal of the operational amplifier is connected to a reference potential terminal. The output terminal of the operational amplifier outputs a feedback control voltage and inputs the feedback control voltage to the error amplification inverting input terminal of the phase-shifted full-bridge control chip.

[0009] The present invention is further configured such that the setting signal input module includes a setting voltage divider unit, which is used to perform voltage division processing on the power setting signal input from the external control terminal, and input the voltage-divided setting signal to the error amplification in-phase input terminal of the phase-shift full-bridge control chip, so that the phase-shift full-bridge control chip generates a phase shift adjustment signal according to the voltage difference between the error amplification inverting input terminal and the error amplification in-phase input terminal.

[0010] The present invention is further configured such that the primary-side current detection module includes a primary-side current sampling unit, a common-mode rejection unit, and a rectification processing unit. The primary-side current sampling unit is used to collect the current signal on the primary side of the high-frequency boost module, the common-mode rejection unit is used to suppress common-mode interference in the primary-side current signal, and the rectification processing unit is used to convert the primary-side current signal into a current detection voltage and input the current detection voltage to the current detection terminal of the phase-shifted full-bridge control chip.

[0011] The invention is further configured such that the protection module compares the current detection voltage with a preset current protection threshold. When the current detection voltage exceeds the preset current protection threshold, the phase-shifted full-bridge control chip stops outputting the bridge arm drive control signal to suppress the current overshoot caused by the negative resistance discharge of the axial fast-flow CO2 laser.

[0012] The present invention is further configured such that the phase-shifted full-bridge inverter module includes a first bridge arm and a second bridge arm, and the first bridge arm and the second bridge arm respectively include a pair of power switching devices; the multi-bridge arm drive output terminal is connected to the control terminal of the corresponding power switching device via a drive amplification unit and an isolation drive unit, so that the first bridge arm and the second bridge arm are alternately turned on according to the phase shift control relationship output by the phase shift control module.

[0013] The present invention is further configured such that the high-frequency boost module includes at least one high-frequency transformer, the high-voltage rectifier output module includes a high-voltage rectifier unit, the secondary winding of the high-frequency transformer is connected to the high-voltage rectifier unit, and the high-voltage rectifier unit is used to rectify the secondary output voltage of the high-frequency transformer and form a high-voltage DC output terminal.

[0014] The present invention is further configured to include an overvoltage detection module, which is connected to the high voltage DC output terminal and is used to collect the voltage status of the high voltage DC output terminal. When the voltage at the high voltage DC output terminal reaches a preset overvoltage condition, an overvoltage protection signal is output so that the protection module shuts off the drive output of the phase-shifting full-bridge inverter module according to the overvoltage protection signal.

[0015] The invention is further configured to include an isolation transmission module, a centralized control module, and a water-cooled heat dissipation module; the isolation transmission module is connected between the external control terminal and the setting signal input module, and is used to electrically isolate and transmit start / stop signals, power setting signals, or protection interlock signals input from the external control terminal; the centralized control module is used to generate corresponding power setting signals according to the power setting, light output time, and start / stop status; the water-cooled heat dissipation module is disposed inside the high-voltage DC power supply, and is used to dissipate heat from the heat-generating devices in the high-voltage DC power supply.

[0016] This invention provides a high-voltage DC power supply for a fast-flowing axial-axis CO2 laser, comprising a three-phase rectifier module, a soft-start filter module, a phase-shifted full-bridge inverter module, a high-frequency boost module, a high-voltage rectifier output module, a setting signal input module, a laser energy feedback module, a phase-shift control module, a primary-side current detection module, and a protection module. The three-phase rectifier module receives three-phase AC input and forms a DC bus voltage. The soft-start filter module is connected between the three-phase rectifier module and the phase-shifted full-bridge inverter module to perform start-up surge suppression and filtering on the DC bus voltage. The phase-shifted full-bridge inverter module converts the DC bus voltage into a high-frequency AC voltage. The high-frequency boost module is connected to the phase-shifted full-bridge inverter module to isolate and boost the high-frequency AC voltage. The high-voltage rectifier output module is connected to the high-frequency boost module to convert the boosted high-frequency... The AC voltage rectification provides a high-voltage DC output for the discharge of the axial fast-current CO2 laser; the setting signal input module receives the power setting signal from the external control terminal; the laser energy feedback module receives a feedback signal reflecting the output energy or power of the axial fast-current CO2 laser; the phase shift control module is connected to the setting signal input module, the laser energy feedback module, and the phase-shifted full-bridge inverter module, respectively, and adjusts the phase shift angle of the phase-shifted full-bridge inverter module according to the deviation between the power setting signal and the feedback signal to adjust the high-voltage DC output; the primary-side current detection module detects the current state on the primary side of the high-frequency boost module; the protection module is connected to the primary-side current detection module and the phase shift control module, respectively, and shuts off the drive output of the phase-shifted full-bridge inverter module when the primary-side current reaches the preset protection condition. The beneficial effects include: 1. By using a high-resolution sampling circuit to accurately acquire the output current, and combining the phase-shifted full-bridge main circuit topology and bridge arm drive timing optimization, the power supply can quickly identify changes in the primary side current and adjust or shut down the drive output in a timely manner when the load changes. This improves the current output accuracy and dynamic response speed, suppresses current overshoot under the negative resistance characteristics of gas, and thus improves the discharge stability, beam quality and processing consistency of the axial fast-current CO2 laser. 2. By adopting a power supply structure that combines full-bridge inverter, high-frequency boost, integrated magnetic components and water cooling, the heat-generating components under high power output conditions can be centrally cooled, and the dependence of traditional large-volume power frequency or low-frequency power supply structures on external heat dissipation devices is reduced. This improves the energy conversion efficiency and power density under high power output conditions, reduces the power supply volume, and makes the high-voltage DC power supply more suitable for long-term operation in axial fast-current CO2 laser equipment. 3. By setting up an isolation transmission module between the external control terminal and the power control terminal, and combining it with the high-frequency switching power supply control structure, primary current detection module and protection module, the electromagnetic interference of start / stop signals, power setting signals and protection interlock signals is reduced during transmission. At the same time, when the primary current exceeds the preset current protection threshold, the bridge arm drive output of the phase-shifting full-bridge control chip is turned off, which improves the anti-interference capability of the control signal, reduces the risk of false triggering of protection, and can quickly cut off abnormal discharge, thereby reducing the damage of arc discharge, current overshoot and pre-ionization abnormalities to the power supply and laser. 4. By adopting domestically produced magnetic components, integrated topology, and a design approach that reduces the number of discrete components, the high-voltage DC power supply can meet the requirements of high-voltage output and high-frequency isolation while reducing the dependence on core components, simplifying component configuration, reducing manufacturing costs, and improving subsequent maintenance convenience, thereby reducing the usage and maintenance costs of high-voltage DC power supplies for axial fast-flow CO2 lasers of the same power level. 5. By setting up an outer shell structure adapted to the operating environment of the high-voltage power supply, and combining moisture-proof and corrosion-proof treatment, conductive continuity shielding structure, interface shielding connection, heat dissipation channel and modular maintenance structure, the internal control circuit, power devices and connection terminals of the power supply can maintain stable operation in dust, humidity, vibration and electromagnetic interference environments, which enhances the adaptability to harsh working conditions, reduces the impact of environmental interference on the operation of the power supply, and improves the convenience of maintenance, thereby improving the long-term operational reliability of the high-voltage DC power supply for the axial fast-current CO2 laser. 6. By setting up a laser energy feedback module, a setting signal input module, and a phase shift control module, the feedback signal reflecting the laser output energy or output power and the power setting signal input from the external control terminal jointly participate in the phase shift angle adjustment of the phase-shift full-bridge inverter module, so that the high-voltage DC output can be closed-loop corrected according to the actual output state of the laser, thereby improving the output voltage stability and laser power stability under wide operating conditions. 7. By adopting a control structure that combines power setting signal input, laser energy feedback adjustment, primary current detection protection, and high-voltage rectification output, the power supply can adjust the high-voltage DC output according to the output power requirements, discharge state, and load changes of different axis fast-current CO2 lasers. This improves the adaptability to laser loads with different power levels, discharge states, and operating modes, thereby enhancing the compatibility of a single high-voltage DC power supply with multi-type axis fast-current CO2 laser loads. 8. By adopting a high-frequency isolation boost structure, a phase-shifted full-bridge soft-switching control method, a centralized control module, and a protection and detection module, the power supply can complete energy conversion, light output control, power setting, and abnormal protection under high-frequency operating conditions. This improves energy conversion efficiency and fault location efficiency, reduces operating energy consumption, and thus enhances the intelligent operation and maintenance capabilities and long-term operating economy of the high-voltage DC power supply for the axial fast-current CO2 laser.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A hardware block diagram of a high-voltage DC power supply for an axial fast-flow CO2 laser is shown as an exemplary embodiment of the present invention. Figure 2 A schematic diagram of the overall circuit operation principle is shown as an exemplary embodiment of the present invention; Figure 3 A schematic diagram of the main control PCB board circuit is shown as an exemplary embodiment of the present invention; Figure 4 A schematic diagram of a high-voltage PCB board circuit is shown as an exemplary embodiment of the present invention. Figure 5 A schematic diagram of an isolated transmission PCB circuit as shown in an exemplary embodiment of the present invention. Figure 6 A schematic diagram of a centralized control PCB board circuit is shown as an exemplary embodiment of the present invention. Figure 7 A high-voltage power supply water-cooled plate diagram illustrating an exemplary embodiment of the present invention; Figure 8 A high-voltage power supply housing diagram illustrating an exemplary embodiment of the present invention; Figure 9 The diagram illustrates the SPT control code as an exemplary embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0022] A high-voltage DC power supply for an axial fast-flow CO2 laser includes: a three-phase rectifier module, a soft-start filter module, a phase-shifted full-bridge inverter module, a high-frequency boost module, a high-voltage rectifier output module, a setting signal input module, a laser energy feedback module, a phase shift control module, a primary-side current detection module, and a protection module; The three-phase rectifier module is used to receive three-phase AC input and form DC bus voltage; The soft-start filter module is connected between the three-phase rectifier module and the phase-shifted full-bridge inverter module, and is used to suppress and filter the DC bus voltage during startup. Phase-shifting full-bridge inverter modules are used to convert DC bus voltage into high-frequency AC voltage; The high-frequency boost module is connected to the phase-shifted full-bridge inverter module and is used to isolate and boost the high-frequency AC voltage. The high-voltage rectifier output module is connected to the high-frequency boost module to rectify the boosted high-frequency AC voltage into a high-voltage DC output for use in the discharge of the axial fast-current CO2 laser. The setting signal input module is used to receive power setting signals input from an external control terminal; The laser energy feedback module is used to receive feedback signals that reflect the output energy or output power of the axial fast-flow CO2 laser; The phase shift control module is connected to the setting signal input module, the laser energy feedback module, and the phase-shifted full-bridge inverter module respectively. It is used to adjust the phase shift angle of the phase-shifted full-bridge inverter module according to the deviation between the power setting signal and the feedback signal, so as to adjust the high voltage DC output. The primary current detection module is used to detect the current status on the primary side of the high-frequency boost module; The protection module is connected to the primary current detection module and the phase shift control module respectively, and is used to shut off the drive output of the phase-shifting full-bridge inverter module when the primary current reaches the preset protection condition.

[0023] Specifically, such as Figure 1 As shown, the three-phase rectifier module, soft-start filter module, phase-shifted full-bridge inverter module, high-frequency boost module, and high-voltage rectifier output module sequentially form the main power transmission path, while the setting signal input module, laser energy feedback module, phase shift control module, primary-side current detection module, and protection module form the control and protection path. The three-phase AC input first enters the three-phase rectifier module, where it is rectified to obtain the DC bus voltage. This DC bus voltage is then filtered and suppressed by the soft-start filter module before being input to the phase-shifted full-bridge inverter module. Driven by the phase shift control module, the phase-shifted full-bridge inverter module converts the DC bus voltage into a high-frequency AC voltage. This high-frequency AC voltage is then boosted and isolated by the high-frequency boost module before being input to the high-voltage rectifier output module, which forms the high-voltage DC output used for the discharge of the axial fast-current CO2 laser.

[0024] like Figure 2 As shown, during overall circuit operation, the three-phase AC input is rectified, soft-started, and filtered before entering the power inverter section. The high-frequency voltage output from the power inverter section is boosted by a high-frequency transformer and then enters the high-voltage rectified output section, supplying power to the discharge tube of the axial fast-current CO2 laser through the high-voltage output terminal. Because the axial fast-current CO2 laser exhibits negative resistance characteristics in the glow discharge state, the load current is prone to sudden increases with changes in the discharge state. Therefore, a feedback control link and a protection link are set up outside the main power link. The feedback control link is used to correct the high-voltage output based on changes in the laser's output energy or power, and the protection link is used to quickly shut down the inverter drive when the primary current is abnormal, thereby preventing the discharge current from continuing to rise.

[0025] In one implementation, the high-frequency boost module uses a 70kHz high-frequency transformer to replace the traditional power frequency transformer, thereby reducing the transformer size and improving energy conversion efficiency; the magnetic core of the high-frequency transformer can use domestically produced nanocrystalline magnetic cores to reduce dependence on imported high-frequency transformer magnetic cores and improve the integration of the power supply structure.

[0026] like Figure 3As shown, the phase-shift control module can use the UC3875 phase-shift full-bridge control chip. The UC3875 has an error amplification inverting input terminal, an error amplification non-inverting input terminal, a current detection terminal, and a multi-bridge arm drive output terminal. The laser energy feedback module receives the laser feedback signal. The laser feedback signal is divided to form the UFBKSHUNT feedback sampling signal. The UFBKSHUNT feedback sampling signal enters the negative feedback processing unit composed of operational amplifier U18.1 and external resistors. The negative feedback processing unit includes an input resistor, a feedback resistor, and an operational amplifier. The input resistor is connected between the feedback sampling signal input terminal and the inverting input terminal of the operational amplifier. The feedback resistor is connected between the output terminal and the inverting input terminal of the operational amplifier. The non-inverting input terminal of the operational amplifier is connected to a preset reference potential terminal or a ground reference terminal. The output terminal of the operational amplifier outputs a feedback control voltage and inputs the feedback control voltage to the error amplification inverting input terminal of the UC3875.

[0027] Specifically, the UFBKSHUNT feedback sampling signal is the feedback signal obtained by voltage division of the laser feedback signal. This feedback signal is input to pin 3 of the UC3875 after passing through the negative feedback circuit composed of U18.1. Pin 3 of the UC3875 serves as the inverting input terminal of the error amplifier. The power setting signal input from the external control terminal is the SPT signal. The SPT signal is input to pin 4 of the UC3875 after being divided by 1 / 2. Pin 4 of the UC3875 serves as the non-inverting input terminal of the error amplifier. The voltage difference between pins 3 and 4 of the UC3875 determines the output voltage of pin 2 of the UC3875. The output voltage of pin 2 further determines the phase shift angle θ of the phase-shifted full-bridge inverter module, ultimately adjusting the high-voltage DC output of the high-voltage rectifier output module. When the output voltage of pin 2 of the UC3875 is less than 1V, the phase-shifted full-bridge inverter module achieves a 0° phase shift.

[0028] The power setting signal input from the external control terminal is the SPT signal. After being divided by the setting voltage divider unit, the SPT signal is input to the in-phase input of the error amplifier of the UC3875. Thus, the internal error amplifier of the UC3875 simultaneously receives the feedback control voltage and the power setting voltage, and changes the output state of the error amplifier terminal according to the voltage difference between the two, thereby changing the phase shift angle of the phase-shifted full-bridge inverter module. When the feedback signal indicates that the actual laser output deviates from the set power, the UC3875 adjusts the phase shift relationship between the bridge arm drive signals to change the effective output of the phase-shifted full-bridge inverter module, enabling the high-voltage DC output of the high-voltage rectifier module to undergo closed-loop correction according to the actual operating state of the laser. This control method allows the power output to be adjusted based on the actual output energy of the laser, rather than solely relying on a fixed voltage setting.

[0029] Furthermore, this embodiment employs a dual-loop control method combining a voltage outer loop and a transformer primary-side current constraint loop. The voltage outer loop, formed by the laser energy feedback signal UFBKSHUNT, the power setting signal SPT, and the internal error amplifier of the UC3875, is used to adjust the phase shift angle based on the deviation between the actual laser output and the set output. The transformer primary-side current constraint loop, formed by the primary-side current detection module, common-mode rejection unit, rectification processing unit, and the UC3875 current detection terminal, is used to shut down the bridge arm drive output when the primary-side current exceeds the protection condition. This dual-loop control method improves the current-limiting response capability during load changes and avoids current overshoot caused by the negative resistance characteristics of the gas.

[0030] The primary-side current detection module includes a primary-side current sampling unit, a common-mode rejection unit, and a rectification processing unit. The primary-side current sampling unit collects the current signal from the primary side of the high-frequency boost module, forming ACS1 and ACS2 signals. After common-mode interference suppression by a common-mode choke B82724, the ACS1 and ACS2 signals are rectified to obtain the C / S+ current detection voltage. The C / S+ current detection voltage is input to the current detection terminal of the UC3875. Specifically, the C / S+ current detection voltage is connected to pin 5 of the UC3875, which serves as the current detection terminal. When the primary-side current is within the normal range, the C / S+ voltage is below the preset current protection threshold, and the UC3875 maintains bridge arm drive output. When the primary-side current exceeds the preset range, the C / S+ voltage reaches or exceeds the preset current protection threshold, and the UC3875 stops outputting the bridge arm drive control signal, causing the phase-shifted full-bridge inverter module to stop transferring energy to the high-frequency boost module, thereby suppressing current overshoot caused by the negative resistance discharge of the axial fast-current CO2 laser.

[0031] In one implementation, the voltage threshold corresponding to the primary current protection threshold is 2.5V; when the C / S+ current detection voltage is less than 2.5V, the UC3875 maintains normal output; when the C / S+ current detection voltage exceeds 2.5V, the bridge arm drive output of the UC3875 is turned off, thereby turning off the high voltage output.

[0032] like Figure 4As shown in the high-voltage PCB circuit diagram, the phase-shifted full-bridge inverter module includes at least two bridge arms, each including a pair of power switching devices. The multi-arm drive control signals output by the phase-shifting control module are amplified by a drive amplifier and then input to the control terminals of the corresponding power switching devices, causing the first and second bridge arms to alternately conduct according to a preset phase shift relationship. The high-frequency AC voltage output by the phase-shifted full-bridge inverter module is input to a high-frequency boost module, which may include at least one high-frequency transformer. The secondary winding of the high-frequency transformer is connected to a high-voltage rectifier unit, which rectifies the secondary output voltage of the high-frequency transformer to form a high-voltage DC output terminal. The high-voltage DC output terminal can be connected to a laser discharge tube to provide the high-voltage DC power required for gas breakdown and stable discharge.

[0033] An overvoltage detection module is also installed on the high-voltage output side. This module is connected to the high-voltage DC output terminal and is used to collect the voltage status of the high-voltage DC output terminal. When the voltage at the high-voltage DC output terminal reaches a preset overvoltage condition, the overvoltage detection module outputs an overvoltage protection signal. Based on this signal, the protection module shuts off the drive output of the phase-shifted full-bridge inverter module. Therefore, in cases of abnormally high voltage rectified output, open-circuit laser load, or abnormal discharge state, the overvoltage protection link can block further energy input to the high-voltage side, reducing the risk of damage to high-voltage devices, discharge tubes, and internal power devices of the power supply.

[0034] Furthermore, the overvoltage detection module and the protection module are linked. When the overvoltage detection module detects an abnormal increase in the high voltage output, it outputs an overvoltage protection signal to the protection module. The protection module triggers a shutdown control based on the overvoltage protection signal, causing the phase-shifting full-bridge control chip to stop outputting bridge arm drive control signals, thereby shutting off the high voltage output.

[0035] In other embodiments, the protection module may also be connected to an over-temperature detection circuit, a discharge anomaly detection circuit, or an interlock protection circuit to trigger a shutdown action when device over-temperature, discharge anomaly, or external interlock anomaly occurs, so as to protect the operator, the laser discharge tube, and the power devices inside the high-voltage DC power supply.

[0036] like Figure 5 As shown in the schematic diagram of the isolated transmission PCB board, the isolated transmission module is positioned between the external control terminal and the power control terminal to provide electrical isolation for the transmission of start / stop signals, power setting signals, protection interlock signals, or status feedback signals. The isolated transmission module may include optocoupler isolation devices, analog switching devices, and power isolation branches, creating electrical isolation between the external control system and the internal control circuit of the high-voltage power supply. Through this isolated transmission structure, the control signals output from the external control terminal can be sent to the setting signal input module or the centralized control module, while simultaneously reducing the impact of electromagnetic interference generated by high-power discharge, high-frequency switching operations, and the operation of fans and pumps on the control signals.

[0037] In one implementation, the isolated transmission module employs a 0-10V input / output isolated transmission method. The 0-10V analog control signal input from the external control terminal is transmitted through isolation and then outputs a corresponding 0-10V control signal to transmit power setting signals or status control signals. This 0-10V isolated transmission method reduces the impact of electromagnetic noise generated by high-power discharge, fan inverters, or high-frequency switching on the control signal, preventing control signal distortion or false protection triggering.

[0038] like Figure 6 As shown in the schematic diagram of the centralized control PCB board, the centralized control module receives external start / stop commands, power setting commands, light output control commands, and interlock protection signals, and generates corresponding power setting signals and start / stop control signals based on these signals. The centralized control module can be connected to the CNC control terminal or other upper-level control terminals. Upon receiving a light output permission signal, it converts the power setting value into an SPT signal and outputs it to the setting signal input module. Upon receiving a light outage signal, protection interlock signal, or abnormal status signal, the centralized control module stops outputting valid power setting signals or outputs a shutdown control signal, causing the phase shift control module to stop driving the phase-shifting full-bridge inverter module. Thus, the centralized control module can correlate external processing control requirements with the internal power control process of the high-voltage power supply.

[0039] It should be noted that the UC3875, as a phase-shift full-bridge control chip, is mainly used to realize feedback adjustment, phase-shift control and protection triggering; the centralized control module is used to generate the corresponding SPT power setting signal according to the external power setting, light output time and start / stop status, and provide the SPT power setting signal to the setting signal input module.

[0040] like Figure 7 As shown, a high-voltage power supply water-cooled plate is used to form a water-cooled heat dissipation module. The water-cooled heat dissipation module is located inside the high-voltage DC power supply and is arranged corresponding to the heat-generating areas inside the power supply. These heat-generating areas include the area where the phase-shifted full-bridge inverter module is located, the area where the high-frequency boost module is located, and other areas where power devices are concentrated. The water-cooled plate can be equipped with an inlet, an outlet, and internal cooling channels. Coolant enters the internal channels of the water-cooled plate through the inlet, carries away the heat generated by the heat-generating devices, and is discharged through the outlet. By placing the water-cooled heat dissipation module adjacent to high-power switching devices, magnetic devices, or their mounting substrates, the temperature rise of the high-voltage DC power supply under high-power output conditions can be reduced, allowing the phase-shifted full-bridge inverter module, high-frequency boost module, and high-voltage rectifier output module to maintain within a stable operating temperature range.

[0041] In one embodiment, the water-cooling module is a direct water-cooling system, which is installed inside the high-voltage DC power supply and can dissipate heat from the high-frequency transformer, power switching devices, and other heat-generating components. The direct water-cooling system is integrated with the high-voltage DC power supply housing, allowing the high-voltage DC power supply to dissipate heat from its internal components without the need for an external cooling device.

[0042] like Figure 8 As shown, the high-voltage power supply housing houses a three-phase rectifier module, a soft-start filter module, a phase-shifting full-bridge inverter module, a high-frequency boost module, a high-voltage rectifier output module, a phase-shift control module, a protection module, an isolation transmission module, a centralized control module, and a water-cooling heat dissipation module. The housing can be equipped with input interfaces, output interfaces, control interfaces, mounting holes, and heat dissipation or maintenance structures. The input interface is used to connect to a three-phase AC power supply, the output interface is used to connect to the discharge tube of an axial fast-current CO2 laser, and the control interface is used to connect to an external control terminal or a CNC control terminal. The housing can also be equipped with shielding, grounding, fixing, and maintenance structures according to the installation environment of the high-voltage power supply to improve the assembly stability and maintenance convenience of the power supply in the industrial field.

[0043] In one embodiment, the high-voltage power supply casing adopts a moisture-proof and corrosion-resistant structure, and is combined with a water-cooled heat dissipation module to form a power supply casing suitable for harsh operating conditions. The casing can be made of corrosion-resistant metal materials or corrosion-resistant alloy materials. Sealing elements or shielded connectors can be installed at the casing interfaces. Circuit boards, connectors, or exposed conductors can be treated to prevent moisture, salt spray, or mold, so as to improve the operational stability of the high-voltage DC power supply in dusty, humid, vibrating, and electromagnetic interference environments.

[0044] like Figure 9 As shown, the SPT control code describes the control process of power setting and light emission timing by the centralized control module or external control terminal. The control program generates corresponding SPT power setting signals and light emission control states based on the set power, light emission time, start light emission signal, stop light emission signal, and reset signal. When the start light emission condition is met, the control program outputs an SPT signal corresponding to the set power. The SPT signal is input to the error amplification in-phase input terminal of the phase-shifted full-bridge control chip via the setting voltage divider unit. When the stop light emission condition is reached or a protection signal is detected, the control program stops outputting valid SPT signals or triggers shutdown logic, causing the high-voltage DC power supply to stop providing valid high-voltage output to the laser discharge tube.

[0045] In the above operation, the power setting signal from the external control terminal and the feedback signal generated by the actual laser output jointly determine the output state of the phase shift control module; the primary current detection module and the overvoltage detection module monitor the power supply operating status from the current side and the voltage side, respectively; the protection module shuts off the drive output of the phase-shifting full-bridge inverter module when overcurrent or overvoltage conditions are detected. Therefore, the high-voltage DC power supply can maintain good output stability during the ignition, stable discharge, and power regulation of the axial fast-current CO2 laser, and promptly cut off the power output in case of sudden load changes or abnormal discharge, reducing the impact of current surges caused by the negative resistance characteristics of the gas on the laser and the power supply.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-voltage DC power supply for an axial fast-flow CO2 laser, characterized in that, include: The system includes a three-phase rectifier module, a soft-start filter module, a phase-shifted full-bridge inverter module, a high-frequency boost module, a high-voltage rectifier output module, a setting signal input module, a laser energy feedback module, a phase shift control module, a primary current detection module, and a protection module. The three-phase rectifier module is used to receive three-phase AC input and form DC bus voltage; The soft-start filter module is connected between the three-phase rectifier module and the phase-shifted full-bridge inverter module, and is used to suppress and filter the DC bus voltage during startup. Phase-shifting full-bridge inverter modules are used to convert DC bus voltage into high-frequency AC voltage; The high-frequency boost module is connected to the phase-shifted full-bridge inverter module and is used to isolate and boost the high-frequency AC voltage. The high-voltage rectifier output module is connected to the high-frequency boost module to rectify the boosted high-frequency AC voltage into a high-voltage DC output for use in the discharge of the axial fast-current CO2 laser. The setting signal input module is used to receive power setting signals input from an external control terminal; The laser energy feedback module is used to receive feedback signals that reflect the output energy or output power of the axial fast-flow CO2 laser; The phase shift control module is connected to the setting signal input module, the laser energy feedback module, and the phase-shifted full-bridge inverter module respectively. It is used to adjust the phase shift angle of the phase-shifted full-bridge inverter module according to the deviation between the power setting signal and the feedback signal, so as to adjust the high voltage DC output. The primary current detection module is used to detect the current status on the primary side of the high-frequency boost module; The protection module is connected to the primary current detection module and the phase shift control module respectively, and is used to shut off the drive output of the phase-shifted full-bridge inverter module when the primary current reaches the preset protection condition.

2. The high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 1, characterized in that, The phase-shift control module includes a phase-shift full-bridge control chip. The phase-shift full-bridge control chip is equipped with an error amplification input terminal, a current detection terminal, and a multi-bridge arm drive output terminal. The error amplification input terminal includes an error amplification inverting input terminal and an error amplification non-inverting input terminal. The error amplification inverting input terminal is used to receive feedback signals, and the error amplification non-inverting input terminal is used to receive power setting signals. The multi-bridge arm drive output terminal outputs drive control signals for controlling the switching devices of each bridge arm in the phase-shift full-bridge inverter module.

3. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 2, characterized in that, The laser energy feedback module includes a feedback voltage divider unit and a negative feedback processing unit. The feedback voltage divider unit includes series-connected voltage divider resistors used to divide the laser feedback signal and output a feedback sampling signal at the voltage divider node. The negative feedback processing unit includes an operational amplifier, an input resistor, and a feedback resistor. The input resistor is connected between the voltage divider node and the inverting input terminal of the operational amplifier. The feedback resistor is connected between the output terminal and the inverting input terminal of the operational amplifier. The non-inverting input terminal of the operational amplifier is connected to the reference potential terminal. The output terminal of the operational amplifier outputs a feedback control voltage and inputs the feedback control voltage to the error amplification inverting input terminal of the phase-shifted full-bridge control chip.

4. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 3, characterized in that, The setting signal input module includes a setting voltage divider unit, which is used to divide the power setting signal input from the external control terminal and input the divided setting signal to the error amplification non-inverting input terminal of the phase-shifting full-bridge control chip, so that the phase-shifting full-bridge control chip generates a phase shift adjustment signal based on the voltage difference between the error amplification inverting input terminal and the error amplification non-inverting input terminal.

5. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 2, characterized in that, The primary-side current detection module includes a primary-side current sampling unit, a common-mode rejection unit, and a rectification processing unit. The primary-side current sampling unit is used to collect the current signal on the primary side of the high-frequency boost module. The common-mode rejection unit is used to suppress common-mode interference in the primary-side current signal. The rectification processing unit is used to convert the primary-side current signal into a current detection voltage and input the current detection voltage to the current detection terminal of the phase-shifted full-bridge control chip.

6. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 5, characterized in that, The protection module compares the current detection voltage with the preset current protection threshold. When the current detection voltage exceeds the preset current protection threshold, the phase-shifting full-bridge control chip stops outputting the bridge arm drive control signal to suppress the current overshoot caused by the negative resistance discharge of the axial fast-flow CO2 laser.

7. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 2, characterized in that, The phase-shifted full-bridge inverter module includes a first bridge arm and a second bridge arm, each of which includes a pair of power switching devices. The multi-bridge arm drive output terminal is connected to the control terminal of the corresponding power switching device via a drive amplification unit and an isolation drive unit, so that the first bridge arm and the second bridge arm are alternately turned on according to the phase shift control relationship output by the phase shift control module.

8. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 1, characterized in that, The high-frequency boost module includes at least one high-frequency transformer, and the high-voltage rectifier output module includes a high-voltage rectifier unit. The secondary winding of the high-frequency transformer is connected to the high-voltage rectifier unit, which is used to rectify the secondary output voltage of the high-frequency transformer and form a high-voltage DC output terminal.

9. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 8, characterized in that, It also includes an overvoltage detection module, which is connected to the high-voltage DC output terminal and is used to collect the voltage status of the high-voltage DC output terminal. When the voltage at the high-voltage DC output terminal reaches the preset overvoltage condition, it outputs an overvoltage protection signal so that the protection module can shut off the drive output of the phase-shifting full-bridge inverter module according to the overvoltage protection signal.

10. A high-voltage DC power supply for an axial fast-flow CO2 laser according to claim 1, characterized in that, It also includes an isolation transmission module, a centralized control module, and a water-cooling heat dissipation module; the isolation transmission module is connected between the external control terminal and the setting signal input module, and is used to electrically isolate and transmit start / stop signals, power setting signals, or protection interlock signals input from the external control terminal; the centralized control module is used to generate corresponding power setting signals according to the power setting, light output time, and start / stop status; the water-cooling heat dissipation module is set inside the high-voltage DC power supply, and is used to dissipate heat from the heat-generating components in the high-voltage DC power supply.

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