Modular circuit of high repetition frequency pulse power supply and control method thereof

Abstract

The invention relates to the technical field of power supply circuits, in particular to a modular circuit of a high-repetition-frequency pulse power supply and a control method of the modular circuit. According to the technical scheme, the device comprises a preceding-stage AC-DC charging unit, an energy storage capacitor, two pulse discharging modules connected in parallel and a discharging switch, and the preceding-stage AC-DC charging unit is used for converting alternating current input into direct current. According to the invention, by adopting a standardized and parallelizable modular circuit architecture, flexible and linear adjustment of the maximum output current of the system is realized, the product development and delivery cycle for different current requirements is remarkably shortened, and the customization and maintenance cost is reduced; meanwhile, the total power is dispersed to a plurality of independent modules through the design, the limit requirement for a single power device is lowered, and the reliability and maintainability of the whole system are improved; under the design of synchronous triggering and current sharing, all the modules can cooperatively output high-quality and high-consistency pulse current.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply circuit, and particularly relates to a modular circuit of a high-repetition-frequency pulse power supply and a control method thereof. BACKGROUND

[0002] Pulse lasers play a vital role in industrial processing, medical and cosmetic treatment, scientific research and national defense technology. Among them, diode-pumped solid-state lasers (DPSSL) have become the core light source in the above-mentioned fields due to their high efficiency, small size, long life, good stability and other outstanding advantages. Laser diodes as the pumping source of DPSSL system, their performance directly determines the power, beam quality and reliability of the final laser output. And the driving power supply as the "control center" of the laser diode, the precision and stability of its output current, especially the ability to generate high-repetition-frequency large current pulses, are the key to determine the performance of the whole system.

[0003] At present, the mainstream large-current high-repetition-frequency pulse driving power supply on the market generally adopts a customized design scheme with fixed current level. That is, for a specific laser power and application demand, the parameters such as the topological structure, power switch device, magnetic element and heat dissipation system of the power supply are determined in the design stage, so as to fix its maximum output current. This scheme has the following significant defects:

[0004] Long development cycle and high customization cost: when the market demand changes and different output current specifications of the power supply are needed, even if the core topology does not change, the power stage, key components and control parameters of the power supply must be redesigned, calculated and experimentally verified. This process is time-consuming and laborious, resulting in a long development cycle and high research and development and customization cost.

[0005] Poor flexibility and scalability: the traditional single power supply design lacks the modularization idea, and its output capacity is fixed after the design is completed, which cannot be flexibly and linearly adjusted. In order to adapt to different current demands, the entire power supply main circuit must be redesigned, which lacks scalability and is difficult to quickly respond to diversified market applications.

[0006] Poor system reliability and maintainability: in a single large-power power supply, the core power switch device usually works in the limit state, which is extremely demanding on the performance and reliability of the device itself. Once a key device fails, it is easy to cause the entire power supply system to malfunction, and it is difficult and costly to maintain on site.

[0007] Therefore, there is an urgent need in the art for a high-current high-repetition-rate pulse driving power supply solution that can be flexibly configured, significantly shorten the development cycle, effectively reduce the customization cost, and improve the system reliability and maintainability. The present application proposes a modular circuit of a high-repetition-rate pulse power supply and a control method thereof. SUMMARY

[0008] The purpose of the present application is to address the problem of long development cycle, poor flexibility and scalability of mainstream high-current high-repetition-rate pulse driving power supply in the background art, and proposes a modular circuit of a high-repetition-rate pulse power supply and a control method thereof.

[0009] In a first aspect, the present application provides a modular circuit of a high-repetition-rate pulse power supply, comprising:

[0010] A pre-stage AC-DC charging unit for converting alternating current input into direct current;

[0011] An energy storage capacitor connected to the output end of the pre-stage AC-DC charging unit for storing energy required for pulse discharge;

[0012] At least two pulse discharge modules connected in parallel, the input end of each pulse discharge module being connected to the energy storage capacitor, and the output ends being connected in parallel and then commonly connected to a discharge switch;

[0013] A discharge switch having an input end connected to the output end of the pulse discharge module and an output end connected to a load;

[0014] Wherein, the maximum output current of the system is linearly adjusted by increasing or decreasing the number of parallel pulse discharge modules.

[0015] Optionally, it further comprises a total control unit connected to the pre-stage AC-DC charging unit, each pulse discharge module and the discharge switch, for sending a synchronous trigger signal to each pulse discharge module to control all pulse discharge modules to perform pulse discharge synchronously.

[0016] Optionally, the pulse discharge module is based on a Buck chopper circuit topology.

[0017] Optionally, the pulse discharge module comprises a high-speed switching device, a freewheeling diode and a filter inductor.

[0018] Optionally, the high-speed switching device is a wide-bandgap semiconductor device.

[0019] Optionally, the wide-bandgap semiconductor device is a SiC MOSFET.

[0020] Optionally, the discharge switch comprises a high-power IGBT and a freewheeling diode.

[0021] In a second aspect, the present application provides a control method of a modular circuit of a high-repetition-frequency pulse power supply as described in the first aspect, comprising the following steps:

[0022] charging the energy storage capacitor to a predetermined voltage through the front-stage AC-DC charging unit;

[0023] sending a synchronous trigger signal to all the parallel-connected pulse discharge modules;

[0024] controlling the discharge switch to be turned on, so that the pulse discharge modules output pulse current to the load;

[0025] Each pulse discharge module synchronously operates in response to the synchronous trigger signal, and collectively provides total output pulse current.

[0026] Optionally, before the discharge switch is controlled to be turned on, there is also an inductance energy storage stage: the inductance in the pulse discharge module is controlled to store energy through the synchronous trigger signal, and when the inductance current reaches a set value, the discharge switch is controlled to be turned on.

[0027] Optionally, after the pulse discharge ends, the synchronous trigger signal and the discharge switch are turned off, and the filter inductance in each pulse discharge module flows through a freewheeling diode until the current decreases to zero.

[0028] Compared with the prior art, the present application has at least one of the following beneficial technical effects:

[0029] By increasing or decreasing the number of parallel-connected standardized pulse discharge modules, the maximum output current of the system can be directly and linearly adjusted, without the need to redesign the main circuit for different current requirements.

[0030] With a unified modular architecture, when developing new current specification products, only the parallel connection of modules and the adaptation of mechanical structures are needed, avoiding repeated design and verification of the main circuit topology, magnetic elements and control strategies, shortening the development time and reducing the development and customization costs.

[0031] The total power of the system is shared by multiple modules, reducing the performance limit requirements of a single power device. When a single module fails, it can be isolated and replaced online without causing the entire system to malfunction, improving the mean time between failures and simplifying the maintenance process.

[0032] Under the control of the synchronous trigger signal of the total control unit, all pulse discharge modules can synchronously operate, and in combination with the current sharing design, collectively provide a large current pulse with a flat top and steep front to the load, ensuring the stability and current sharing effect of the multi-module parallel output.

[0033] The application realizes flexible and linear regulation of the maximum output current of the system by adopting a standardized and parallelizable modular circuit architecture, significantly shortens the product development and delivery cycle for different current requirements, and reduces the customization and maintenance costs. Meanwhile, the design disperses the total power to multiple independent modules, reduces the limit requirements for a single power device, and improves the overall reliability and maintainability of the system. Under the synchronous triggering and current sharing design, each module can cooperatively output high-quality and consistent pulse current. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A circuit topology of a high-repetition-frequency pulse power modular circuit design provided by an embodiment of the application;

[0035] Figure 2 A reference circuit of an AC-DC energy storage capacitor charging part provided by an embodiment of the application;

[0036] Figure 3 A reference circuit of a post-stage discharge part provided by an embodiment of the application;

[0037] Figure 4 A voltage and current waveform diagram of a system 400A output pulse provided by an embodiment of the application.

[0038] The drawings show that: 1, a front-stage AC-DC charging unit; 2, an energy storage capacitor unit; 3, a total control unit; 4, a pulse discharge module; 5, a discharge switch unit. DETAILED DESCRIPTION

[0039] The embodiments of the application are described below through specific and concrete examples, and those skilled in the art can easily understand other advantages and effects of the application from the disclosure of the specification. The application can also be implemented or applied through other different specific embodiments, and each detail in the specification can be modified or changed based on different views and applications without departing from the spirit of the application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0040] Embodiment 1

[0041] Reference Figure 1 An embodiment of a high-repetition-frequency pulse power modular circuit design provided by the application includes: a front-stage AC-DC charging unit 1, an energy storage capacitor unit 2, a total control unit 3, a plurality of parallelly connected pulse discharge modules 4, and a discharge switch unit 5.

[0042] The input of the front-stage AC-DC charging unit 1 is connected to the mains. In the embodiment, the unit first rectifies the mains into direct current, and then generates stable 100V direct current to charge the back-stage energy storage capacitor by using the isolation DC-DC technology. Of course, other isolation or non-isolation DC-DC topologies such as flyback and full-bridge can also be used to realize the function.

[0043] The energy storage capacitor unit 2 is composed of a plurality of electrolytic capacitors and film capacitors in parallel, and the positive and negative electrodes thereof are connected to the output positive and negative electrodes of the front-stage DC-DC charging unit 1 respectively. The unit is used to store a large amount of energy required for pulse discharge, and the total capacitance value is determined according to the width of the target output pulse and the system repetition frequency, for example, can be selected as 1000μF.

[0044] The total control unit 3 takes a high-performance digital signal processor (DSP) as the core (such as TMS320F28335 of TI Company). The DSP controls the synchronous output of pulse current of a plurality of back-stage pulse discharge modules through the PWM output pin thereof, and simultaneously controls the front-stage AC-DC charging unit 1 to charge the energy storage capacitor unit 2.

[0045] The plurality of pulse discharge modules 4 are completely identical in structure and electrical parameters, and constitute the core of the application. The input of each module is connected to the energy storage capacitor unit 2 in parallel through a bus bar.

[0046] The discharge switch 5 is composed of a large-current IGBT, the input of which is connected to the parallel-connected pulse discharge modules 4, and the output thereof is also connected in parallel through a copper bar and is commonly connected to the load, which is a laser diode array in the embodiment.

[0047] Reference Figure 2 is shown, which shows the specific circuit composition of the charging unit 1. The unit uses a rectifier bridge 1 to convert the mains into stable direct current, and uses an isolation DC-DC unit 2 to convert the direct current into stable 100V constant current output to charge the back-stage energy storage capacitor.

[0048] Reference Figure 3 is shown, which shows the specific circuit composition of the back-stage discharge part, including the pulse discharge module and the discharge switch. The pulse discharge module is based on the Buck chopper circuit topology, including a high-speed switching device S, a freewheeling diode D, and a filter inductor L, and the actual circuit also includes a driving part, a power supply part and the like. The discharge switch is a large-current electronic switch based on IGBT, including two high-power IGBTs and four freewheeling diodes.

[0049] The working principle and process of the application are as follows:

[0050] Charging stage: the total control unit 3 outputs control instructions to make the pre-stage AC-DC charging unit 1 start to charge the energy storage capacitor unit 2 in a constant current mode until the voltage reaches a preset value (such as 100V). The DSP simultaneously monitors the charging current and voltage to prevent overcharging.

[0051] Standby stage: after charging is completed, the system enters a standby state.

[0052] Inductor energy storage and discharge stage: when a pulse needs to be output, the system first enters the inductor energy storage stage, and the DSP of the total control unit 3 simultaneously sends completely synchronized PWM pulses as trigger signals to the local drive circuits of multiple pulse discharge modules 4. At this time, the system stores energy in the inductors in the pulse discharge modules 4. When the inductor current reaches the output value, the DSP controls the discharge switch 5 to turn on, realizing constant current pulse discharge, and the pulse width is the time when the discharge switch 5 is turned on.

[0053] Turn-off and freewheeling stage: when the set pulse width ends, the total control unit 3 turns off the synchronous trigger signal, and the discharge switch 5 is turned off. The remaining energy in each filter inductor L continues to freewheel through its corresponding freewheeling diode D, and the current flows back to the energy storage capacitor until the inductor current decreases to zero, completing a complete pulse period.

[0054] Effect of the embodiment: assuming that each pulse discharge module 4 can stably output a current of 50A under a pulse width of 300μs, then 8 modules in parallel can stably provide a pulse current of 400A to the load in this embodiment. Referring to Figure 4 , the output current pulse has a flat top and a steep rising edge, and the current deviation between modules is less than 2%, showing excellent current sharing performance and output quality. Through 8 parallel pulse discharge modules, a stable pulse current output of 400A is realized, proving that modular circuit design can achieve the output capability of traditional single power supply through the cooperative work of multiple standard modules. The output current pulse of this embodiment has a flat top and a steep rising edge, and the current deviation between modules is less than 2%, verifying that under the design of synchronous triggering and current sharing, the multi-module parallel system can provide high-quality and highly consistent output waveforms. This embodiment specifically illustrates the selection and connection relationship of the pre-stage AC-DC charging, energy storage capacitor, total control unit (DSP), pulse discharge module (based on Buck circuit), and discharge switch (IGBT), providing a specific implementation scheme for modular design.

[0055] Embodiment 2:

[0056] On the basis of embodiment 1, if the system output current capacity needs to be increased to 600A, without changing any circuit design, only four same pulse discharge modules 4 are needed to be connected in parallel in the original system. The general discharge switch is designed for 1000A, which can be compatible with 600A current output. At this time, the total control unit 3 of the system does not need to be modified in hardware, and only needs to identify the number of modules or directly output the synchronous trigger signal in software (because its driving capacity is sufficient to drive more local driving circuits of the module). 12 modules work together under the synchronous trigger, automatically current-sharing, realizing the linear doubling of the output capacity. This fully proves the core advantage of the application that the flexible expansion is realized through modularization. On the basis of embodiment 1, only by increasing 4 same pulse discharge modules, the system output current capacity can be increased from 400A to 600A, without changing the main circuit topology, control architecture and key component selection. In order to meet the new and higher current demand, the whole power supply does not need to be redesigned, only the module superposition is needed on the existing mature architecture, which significantly shortens the research and verification time of upgrading iteration. The driving capacity of the original discharge switch (designed for 1000A) and the total control unit can be compatible with the new working condition after the number of modules is increased, which shows that the core components have a certain design margin to support the linear expansion of the system.

[0057] The above specific embodiments are only several optional embodiments of the application, and based on the technical solutions of the application and the related inspiration of the above embodiments, those skilled in the art can make various alternative improvements and combinations on the above specific embodiments.

Claims

1. A modular circuit for a high repetition frequency pulse power supply, characterized in that, include: The pre-amplifier AC-DC charging unit is used to convert AC input to DC power; An energy storage capacitor is connected to the output terminal of the front-end AC-DC charging unit and is used to store the energy required for pulse discharge. At least two pulse discharge modules are connected in parallel. The input terminal of each pulse discharge module is connected to the energy storage capacitor, and the output terminals are connected in parallel and then connected to the discharge switch. A discharge switch, the input terminal of which is connected to the output terminal of the pulse discharge module, and the output terminal of which is connected to the load; The maximum output current of the system is linearly adjusted by increasing or decreasing the number of the pulse discharge modules connected in parallel.

2. The modular circuit of a high repetition frequency pulse power supply according to claim 1, characterized in that, It also includes a main control unit, which is connected to the front-end AC-DC charging unit, each of the pulse discharge modules and the discharge switch, and is used to send a synchronous trigger signal to each of the pulse discharge modules to control all pulse discharge modules to perform pulse discharge synchronously.

3. The modular circuit of a high repetition frequency pulse power supply according to claim 1, characterized in that, The pulse discharge module is based on a Buck chopper circuit topology.

4. The modular circuit of a high repetition frequency pulse power supply according to claim 3, characterized in that, The pulse discharge module includes a high-speed switching device, a freewheeling diode, and a filter inductor.

5. The modular circuit of a high repetition frequency pulse power supply according to claim 4, characterized in that, The high-speed switching device is a wide bandgap semiconductor device.

6. The modular circuit of a high repetition frequency pulse power supply according to claim 5, characterized in that, The wide bandgap semiconductor device is a SiC MOSFET.

7. The modular circuit of a high repetition frequency pulse power supply according to claim 1, characterized in that, The discharge switch includes a high-power IGBT and a freewheeling diode.

8. A control method for a modular circuit of a high repetition frequency pulse power supply as described in any one of claims 1-7, characterized in that, Includes the following steps: The energy storage capacitor is charged to a predetermined voltage by the front-end AC-DC charging unit. Send a synchronization trigger signal to all the pulse discharge modules connected in parallel; The discharge switch is turned on, causing the pulse discharge module to output pulse current to the load; Each of the pulse discharge modules responds to the synchronization trigger signal, operates synchronously, and together provides the total output pulse current.

9. The control method for a modular circuit of a high repetition frequency pulse power supply according to claim 8, characterized in that, Before the discharge switch is turned on, there is an inductor energy storage stage: the inductor in the pulse discharge module is controlled to store energy by the synchronous trigger signal, and the discharge switch is turned on when the inductor current reaches the set value.

10. The control method for a modular circuit of a high repetition frequency pulse power supply according to claim 8, characterized in that, After the pulse discharge ends, the synchronous trigger signal and the discharge switch are turned off, and the filter inductors in each pulse discharge module continue to flow through the freewheeling diode until the current drops to zero.

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