Laser repetition frequency pulse power supply circuit and laser

Abstract

The invention belongs to the technical field of high-power laser power supply systems, and discloses a laser repetition frequency pulse power supply circuit and a laser, the laser repetition frequency pulse power supply circuit comprises a front-stage charging power supply module, a rear-stage driving discharge module and a plurality of energy storage modules, the front-stage charging power supply module is connected with a direct current bus end for supplying power to the front-stage charging power supply module, and the rear-stage driving discharge module is connected with a load. The plurality of energy storage modules are connected between the front-stage charging power supply module and the rear-stage driving discharging module, the front-stage charging power supply module comprises a two-phase interleaved magnetic integration CRM-Boost DC-DC topological circuit, and the rear-stage driving discharging module comprises a capacitance energy storage type pulse discharging topological circuit with a tail cutting circuit. The CRM mode is beneficial for reducing conduction loss and improving efficiency, the Boost circuit has the advantages of large step-up ratio and stable output voltage, the rear-stage driving discharge module adopts a capacitance energy storage type pulse discharge topology with a tail-cutting circuit, absorption loop control is added, high-voltage output can be realized, and stress of a switching tube can be reduced at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-power laser power supply systems, and particularly relates to a laser repetitive pulse power supply circuit and a laser. Background Art

[0002] The energy transmission in the space power supply system is inseparable from the working environment. High-power loads in the aerospace laser power supply system are increasingly widely used. It is urgent to improve the output level of the laser repetitive pulse power supply, which puts forward higher requirements for the design of the laser power supply system. With the development of laser power supply technology, the aerospace laser repetitive pulse power supply plays an important role and must achieve breakthroughs in many aspects. Since the aerospace laser repetitive pulse power supply needs to achieve the dual goals of high efficiency and high power density, while improving efficiency and power density at present, how to realize a laser repetitive pulse power supply with high voltage, large current, high repetition frequency and pulse width is the key point and difficulty in the design. Summary of the Invention

[0003] The present invention proposes an aerospace laser repetitive pulse power supply circuit based on silicon carbide. By adopting a front-stage charging power supply module and a rear-stage driving and discharging module of SiCMOSFET, the front-stage circuit adopts a coupled inductor form, the topology adopts an interleaved parallel Boost circuit, and the critical state mode is adopted. The rear-stage topology adopts a capacitive energy storage circuit, and an absorption circuit control is added. It can achieve the characteristics of high voltage, large current, high repetition frequency and pulse width output.

[0004] The specific technical solution adopted by the present invention is: a laser repetitive pulse power supply circuit, including a front-stage charging power supply module, a rear-stage driving and discharging module and a plurality of energy storage modules. The front-stage charging power supply module is connected to the DC bus terminal that supplies power to it, the rear-stage driving and discharging module is connected to the load, and the plurality of energy storage modules are connected between the front-stage charging power supply module and the rear-stage driving and discharging module;

[0005] The front-stage charging power supply module includes a magnetically integrated CRM-Boost DC-DC topology circuit with two-phase interleaved parallel connection, which boosts the supply voltage and charges the plurality of energy storage modules;

[0006] The rear-stage driving and discharging module includes a capacitive energy storage type pulse discharging topology circuit with a tail-cutting circuit, which is supplied with energy by the plurality of energy storage modules and outputs a pulse current with a repetition frequency.

[0007] Further, the CRM-Boost DC-DC topology circuit includes a first MOSFET - Q1, a first coupled inductor L1, a first diode D1, a second MOSFET - Q2, a second coupled inductor L2, a second diode D2, a capacitor C0, and a resistor R Ld ; input terminal Vin The positive electrodes are respectively connected to the like-named ends of the first coupled inductor L1 and the second coupled inductor L2. The unlike-named ends of the first coupled inductor L1 are respectively connected to the drain of the first MOSFET-Q1 and the positive electrode of the first diode D1. The unlike-named ends of the second coupled inductor L2 are respectively connected to the drain of the second MOSFET-Q2 and the positive electrode of the second diode D2. The negative electrodes of the first diode D1 and the second diode D2 are respectively connected to one end of the capacitor C0 and the resistor R Ld One end of the first MOSFET-Q1 and the source of the second MOSFET-Q2 are respectively connected to the other end of the capacitor C0 and the resistor R Ld The other end is connected.

[0008] Furthermore, both the first MOSFET-Q1 and the second MOSFET-Q2 in the CRM-Boost DC-DC topology circuit are silicon carbide semiconductor field effect transistors (SiC MOSFETs).

[0009] Furthermore, the input current operating mode of the magnetically integrated CRM-Boost DC-DC topology circuit adopts the critical conduction mode (CRM). The waveforms of the drive signals of the first MOSFET-Q1 and the second MOSFET-Q2 are 180° out of phase. The waveforms of the inductor currents of the first coupled inductor L1 and the second coupled inductor L2 are 180° out of phase;

[0010] The waveforms of the drive signals of the first MOSFET-Q1 and the inductor current of the first coupled inductor L1 are in phase. The waveforms of the drive signals of the second MOSFET-Q2 and the inductor current of the second coupled inductor L2 are in phase.

[0011] Furthermore, the closed-loop circuit of the post-stage pulse discharge module includes an error amplification circuit, a power amplification circuit, a current sampling circuit, and a feedback circuit;

[0012] The error circuit includes a first resistor R1, a first capacitor C1, a second resistor R2, and an amplifier U1. When the pulsed current given signal passes through, the stray signals are filtered out and output to the power amplification circuit;

[0013] The power amplification circuit includes a totem pole drive circuit composed of a third triode Q3 and a fourth triode Q4, a third resistor R3, and a fourth resistor R4. The voltage signal output by the error circuit is filtered by the third resistor R3 and amplified by the totem pole drive circuit and then flows through the fourth resistor R4 to drive the switching tube S;

[0014] The current sampling circuit includes a sampling resistor R C, the fourth capacitor C4, and the fifth resistor R5 are used to convert the pulsed current signal I on the main circuit L into a voltage signal;

[0015] The feedback circuit includes the second capacitor C2, the third capacitor C3, and the fourth capacitor C4, and is used to control the output pulsed current to follow the pulsed current given signal Iref.

[0016] Furthermore, the energy storage module is an electrolytic capacitor.

[0017] Furthermore, both the first diode D1 and the second diode D2 are fast recovery diodes.

[0018] On the other hand, a multi-channel cascaded laser pulse repetition rate power supply circuit cascades the input ends and output ends of several above-mentioned laser pulse repetition rate power supply circuits head-to-tail for different loads to meet the requirements of system output indicators.

[0019] On yet another hand, a laser includes the laser pulse repetition rate power supply circuit described in any one of the above.

[0020] Generally speaking, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0021] 1. The pre-stage charging power supply module adopts an interleaved parallel CRM-Boost DC-DC topology circuit based on magnetic integration, which effectively reduces the input current ripple and power loss. The CRM mode is beneficial to reducing the conduction loss and improving the efficiency. The Boost circuit has the advantages of a large boost ratio and stable output voltage;

[0022] 2. The post-stage drive discharge module adopts a capacitive energy storage type pulse discharge topology with a tail-cutting circuit, and at the same time adds an absorption circuit control. It can reduce the stress of the switching tube while achieving high voltage output. At the same time, on the premise of considering the synchronous conduction of parallel switching tubes, it can accelerate the rising edge of the pulse waveform and reduce the top drop. When the switching tube is turned off, the tail-cutting circuit is connected to the main circuit to optimize the falling edge of the waveform;

[0023] 3. The introduction of the interleaved parallel technology effectively reduces the input current ripple and power loss; in the CRM mode, the conduction loss of the power device is effectively reduced and the efficiency is improved;

[0024] 4. The silicon carbide semiconductor field effect transistor has the characteristics of high voltage resistance, fast switching speed, high operating frequency, heat resistance and radiation resistance in high power and high frequency applications. Compared with Si MOSFET, the silicon carbide semiconductor field effect transistor has an operating temperature as high as 600°C, a breakdown field strength 10 times that of Si materials, and a much higher operating voltage than similar Si devices, meeting the requirements of anti-radiation, high voltage, high frequency, and high temperature. Its advantages are more suitable for the power supply design for aerospace applications;

[0025] 5. The power inductor adopts a reverse coupling method, further reducing the power supply volume, decreasing the current ripple, achieving the balance of low current ripple and equivalent steady state (inductor current turn-off process) and transient inductor (inductor current turn-on process) response, improving the efficiency and reducing the loss of power devices;

[0026] 6. Connecting the input and output ends of the laser repetitive pulse power supply circuit composed of multiple pre-stage charging power supply modules and post-stage driving discharge modules end to end can meet the requirements of different loads, facilitate modular configuration, make the system have good scalability and flexibility, and the operation of each module is independent of each other, with high reliability. Description of the Drawings

[0027] Figure 1 It is the design block diagram of the laser repetitive pulse power supply circuit in an embodiment of the present invention;

[0028] Figure 2 It is the structure block diagram of the pre-stage charging power supply module in an embodiment of the present invention, where (2a) is the alternating magnetic flux diagram of the side column and the middle column, (2b) is the equivalent magnetic circuit diagram of the coupled inductor, and (2c) is the three-dimensional diagram of the inductance current pulsation coefficient ratio of the coupled inductor and the discrete inductor;

[0029] Figure 3 It is the structure block diagram of the post-stage driving discharge module in an embodiment of the present invention, where (3a) is the pulse discharge topology diagram of the tail-cutting circuit, (3b) is the closed-loop circuit of the pulse discharge module, and (3c) is the driving circuit diagram of the SiC MOSFET;

[0030] Figure 4 It is the schematic diagram of the discrete inductor topology in the CRM state of the CRM-Boost DC-DC topology circuit in an embodiment of the present invention;

[0031] Figure 5 It is the waveform diagram of the discrete inductor topology in the CRM state of the CRM-Boost DC-DC topology circuit in an embodiment of the present invention;

[0032] Figure 6 It is the waveform diagram of the coupled inductor topology in the CRM state of the CRM-Boost DC-DC topology circuit in an embodiment of the present invention;

[0033] Figure 7 It is the multi-stage stacking design structure diagram of the laser repetitive pulse power supply circuit in an embodiment of the present invention. Detailed Embodiments

[0034] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application; in addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0036] As Figure 1 shown, a laser pulse repetition rate power supply circuit of the present application includes a pre-stage charging power supply module, a post-stage driving and discharging module, and a plurality of energy storage modules. The pre-stage charging power supply module is connected to the DC bus terminal that powers it, the post-stage driving and discharging module is connected to the load, and the plurality of energy storage modules are connected between the pre-stage charging power supply module and the post-stage driving and discharging module. The pre-stage charging power supply module includes a magnetically integrated CRM-Boost DC-DC topology circuit with two-phase interleaved parallel connection, which boosts the supply voltage and charges the plurality of energy storage modules. This topology can maintain stable output dynamic characteristics, reduce current ripple, improve efficiency, and reduce power device losses. According to the application scenarios and power requirements of space power, by analyzing the magnetic circuit of the coupled inductor and considering various factors such as the magnetic core structure, magnetic flux density, magnetic resistance, magnetic flux linkage, and air gap of magnetic integration, the magnetic integration technology can reduce the impact on the converter, proving the rationality and feasibility of the design of the pre-stage charging power supply module. The post-stage driving and discharging module is connected in parallel to the load terminal and includes a capacitive energy storage type pulse discharging topology circuit with a tail-cutting circuit. It is powered by a plurality of energy storage modules and outputs pulsed current with a repetitive frequency. It can not only withstand high voltage but also optimize the quality of the current output waveform. The absorbing circuit of the tail-cutting will be quickly released when the switching tube is turned off, which can effectively reduce the pulse falling edge time. In this embodiment, there is one energy storage module; in another embodiment, multiple energy storage modules can be connected in series according to needs.

[0037] The interleaved parallel Boost topology circuit has the advantages of simple control, large boost ratio, small input current ripple, interleaved balance, and convenient modular design. If a problem occurs in one of the phases, the impact on the converter will be greatly reduced. Its input current ripple is correspondingly reduced after the superposition of the current ripples of the two-phase inductors, the switching frequency becomes twice, each path bears half of the total power, the total power is evenly distributed, it has lower device current stress and higher power level, reduces the operating cost, improves the overall efficiency and power density of the machine, and increases the effective payload of the aerospace satellite. Compared with the single-phase, the interleaved parallel circuit has more obvious advantages. It is suitable for application in the boost module of the high-power non-isolated high-voltage space secondary distribution power supply.

[0038] As Figure 4 shown, in this embodiment, the CRM-Boost DC-DC topology circuit includes a first MOSFET - Q1, a first coupled inductor L1, a first diode D1, a second MOSFET - Q2, a second coupled inductor L2, a second diode D2, a capacitor C0, and a resistor R Ld ; the positive pole of the input terminal V in is respectively connected to the same-named ends of the first coupled inductor L1 and the second coupled inductor L2. The different-named end of the first coupled inductor L1 is respectively connected to the drain of the first MOSFET - Q1 and the positive pole of the first diode D1. The different-named end of the second coupled inductor L2 is respectively connected to the drain of the second MOSFET - Q2 and the positive pole of the second diode D2. The negative poles of the first diode D1 and the second diode D2 are respectively connected to one end of the capacitor C0 and one end of the resistor R Ld . The sources of the first MOSFET - Q1 and the second MOSFET - Q2 are respectively connected to the other end of the capacitor C0 and the other end of the resistor R Ld . When the first MOSFET - Q1 is turned on and the second MOSFET - Q2 is turned off, the bus input voltage V in charges the first coupled inductor L1 and rises linearly. The energy stored in the capacitor C0 flows to the load end, and the power flows to the load end through the second diode D2; when the second MOSFET - Q2 is turned on and the first MOSFET - Q1 is turned off, the bus input voltage V in charges the second coupled inductor L2 and rises linearly. The energy stored in the capacitor C0 flows to the load end, and the power flows to the load end through the first diode D1; when both the first MOSFET - Q1 and the second MOSFET - Q2 are turned on, the bus input voltage V inWhen charging the first coupled inductor L1 and the second coupled inductor L2, the energy stored in the capacitor C0 flows to the load terminal; when the first MOSFET - Q1 and the second MOSFET - Q2 are both turned off, the first diode D1 and the second diode D2 conduct, and the capacitor C0 is charged, and the power flows directly from the bus terminal to the load terminal. In this embodiment, both the first diode D1 and the second diode D2 are fast - recovery diodes.

[0039] Meanwhile, in order to improve the high - voltage resistance, fast switching speed, high operating frequency, heat resistance and radiation resistance of the control switch transistors, the control switch transistors, the first MOSFET - Q1 and the second MOSFET - Q2, in the CRM - Boost DC - DC topology circuit are both SiC MOSFETs.

[0040] In the boost - conversion discrete - inductor topology, a low - ripple input current can be achieved, but the inductor - current ripple will not be reduced, and the alternating magnetic flux generated in the middle leg of the corresponding magnetic core remains unchanged, and there is no substantial change in the loss of the power device. In order to achieve the balance between low - current ripple and the equivalent steady - state (inductor - current turn - off process) and transient inductor (inductor - current turn - on process) responses, the input - current operating mode of the magnetically - integrated CRM - Boost DC - DC topology circuit adopts the critical - conduction mode. The waveforms of the drive signals of the first MOSFET - Q1 and the second MOSFET - Q2 are 180° out of phase, and the waveforms of the inductor currents of the first coupled inductor L1 and the second coupled inductor L2 are 180° out of phase; meanwhile, the waveform of the drive signal of the first MOSFET - Q1 and the waveform of the inductor current of the first coupled inductor L1 are in the same phase, and the waveform of the drive signal of the second MOSFET - Q2 and the waveform of the inductor current of the second coupled inductor L2 are in the same phase.

[0041] As Figure 2 (2a) shows, for the two - phase integration, the voltages V1 and V2 on the first path and the second path are 180° out of phase, and the alternating magnetic fluxes applied to the two side - leg windings of the three - leg magnetic core are the same and 180° out of phase. In interleaved parallel connection, it is desired that the alternating magnetic flux in the middle leg is smaller. It can be seen that the alternating magnetic flux in the forward - coupling mode is significantly larger than that in the reverse - coupling mode. Although the discrete inductor and the coupled inductor are consistent in the working state and the drive - signal timing, the parameter design of the magnetic components of the coupled inductor is very different, and magnetic - circuit analysis is required to verify the applicability of the coupled inductor in interleaved parallel connection. Through Figure 2 (2b) gives the equivalent magnetic - circuit model of the coupled inductor. According to Ampere's law, the magnetic - flux circuits of the two side legs are calculated as shown in formula (1):

[0042]

[0043] Among them, in the formula, R s and Rc represent the reluctances of the coupled inductor side legs and the middle leg respectively, φ1 and φ2 are the DC magnetic fluxes of the left and right side legs respectively, N cp is the number of turns of the coil, i L1 is the current of the first inductor, i L2 is the current of the second inductor.

[0044] According to the above formula (1), it can be known that the voltages on the first and second inductor windings of the two-phase integration are obtained by differentiating the magnetic flux, as shown in formula (2):

[0045]

[0046] When selecting a three-leg magnetic core, since the effective cross-sectional area of the middle leg of the magnetic core is approximately twice that of the side leg, and the reluctance is one-half of that of the side leg. If the self-inductance values before and after coupling remain unchanged, the stronger the coupling coefficient, the larger the number of turns of the coupled inductor winding, and it is necessary to increase the winding and the cross-sectional area of the magnetic core, resulting in an increase in the inductor volume. The stronger the coupled inductor, the smaller its transient equivalent inductance value, and the larger the input current ripple. Therefore, a compromise selection of the coupling coefficient is required during design. The side legs and the middle leg of the magnetic core have the same air gap, so the coupling coefficient of the two windings in the coupled inductor is as shown in formula (3):

[0047]

[0048] Among them, k is the coupling coefficient, M is the mutual inductance coefficient, and L is the self-inductance coefficient.

[0049] Through analysis, the use of magnetic integration technology can effectively reduce the steady-state inductor current ripple, while ensuring a fast transient response speed of the converter and reducing voltage disturbance. With the same three-segment air gap, as the duty cycle increases, the reduction ratio of the inductor current ripple is large, and as the coupling coefficient increases, the reduction ratio of the inductor current ripple also increases. The larger its transient equivalent inductance value, the larger the magnetic flux in the magnetic core, the larger the number of turns of the winding, and the larger the volume. The stronger the coupling coefficient, the larger the input current ripple. In order to minimize the inductor current ripple as much as possible and improve the dynamic response speed. When designing the coupled inductor, increase the equivalent steady-state inductance as much as possible to correspondingly reduce the transient equivalent inductance.

[0050] From Figure 2 (2c), it can be seen that the ratio of the two ripple coefficients is always less than 1, and the inductor current ripple of the coupled inductor is smaller than that of the discrete inductor under any conversion conditions. For the boost converter with a coupled inductor, when the duty cycle is greater than 0.5, it can be seen that this suppression effect increases with the increase of the coupling coefficient. Due to the decrease of the inductor current ripple, the turn-on loss of its power device decreases accordingly, having a better efficiency advantage.

[0051] Assume that the topology operates in the CRM state. Let D be the duty cycle, V1 and V2 be the voltages corresponding to the inductors in the two-phase Boost circuit respectively. Both V1 and V2 can be represented by the combination of V in and V o In the cases of D ≤ 0.5 and D > 0.5, there are four different stages, namely four current directions. The working states of each component in its main circuit are analyzed as shown in Table 1 below:

[0052] Table 1 Analysis Table of Circuit Working States for D ≤ 0.5 and D > 0.5

[0053]

[0054] As Figure 5 shown, the working state of each Boost circuit in the interleaved parallel circuit is the same as that of a single Boost circuit. For the interleaved parallel circuit, the phases of the driving signals and the inductor current waveforms differ by 180°. The input-output variation relationship in the stable state of the discrete inductor is obtained through the inductor volt-second balance principle. Among them, the left figure is the waveform diagram when D ≤ 0.5, and the right figure is the waveform diagram when D > 0.5.

[0055] Assume that the converter operates in the CRM state. The coils, materials, and winding structures of the coupled inductors are exactly the same. For D ≤ 0.5 and D > 0.5, the converter has four different working stages respectively. According to the following formula (4),

[0056]

[0057] where V1 and V2 in the formula are the voltages corresponding to the inductors in the two-phase Boost circuit respectively, L1 and L2 are the self-inductance coefficients corresponding to the inductors in the two-phase Boost circuit respectively, and are the differentials of the inductor currents in the two-phase Boost circuit respectively, is the differential of i L1 and i L2 sum, α is the coupling coefficient, M is the coupled inductance, i L1 is the current of the first inductor, i L2 is the current of the second inductor;

[0058] and formula (5),

[0059]

[0060] where in the formula, L is the self-inductance coefficient, M is the mutual inductance coefficient, D is the duty cycle, V in is the input voltage, V o is the output voltage, T s is the switching period.

[0061] The relationship of the change rate of the inductor current at each stage can be obtained and is listed in Table 2 below:

[0062] Table 2 Change Rate of Inductor Current

[0063]

[0064]

[0065] As Figure 6 shown, when D ≤ 0.5, the discharge rate of the inductor current of i L1 is the same during the time period from t1 to t2 and from t3 to t4, and the energy storage area of i L1 is equal to the dotted part of the discrete inductor during the time period from t0 to t4. Similarly, when D > 0.5, a similar conclusion can be obtained. The circuit operating principle and the switching tube control timing within one switching period are the same as those of the discrete inductor circuit. The pulsation value of each-phase inductor current is equal to its peak value, and the average value of each-phase inductor current is 1 / 2 of the peak value. The change rate of the input current is related to the transient equivalent inductance L eq2 and has nothing to do with the equivalent inductance values in other stages. When D ≤ 0.5, the pulsation value during the rising stage of the inductor current is determined by the equivalent steady-state inductance L eq1 . When D > 0.5, the pulsation value during the falling stage of the inductor current is determined by the equivalent steady-state inductance L eq3 . Figure 6 In the waveform, the first and second rows are the driving waveforms, the third and fourth rows are the voltage waveforms, the fifth and sixth rows are the inductor current waveforms, and the seventh row is the input current waveform.

[0066] Taking the first coupled inductor L1 as an example, when analyzing the steady-state operation in the CRM state with D < 0.5 and D > 0.5, through the above analysis, the inductor current of the first coupled inductor L1 is in an equilibrium state within the switching period. When D < 0.5, comparing the change slopes of the inductor current of the first coupled inductor L1 in stage one and stage two, the inductor current slope in stage two is steeper, and waveform distortion occurs during the inductor discharge process. When D > 0.5, comparing the change slopes of the inductor current of the first coupled inductor L1 in stage one and stage two, the inductor current slope in stage one is steeper, and waveform distortion occurs during the inductor charging process.

[0067] Based on the above embodiments, the closed-loop circuit of the post-stage pulse discharge module includes an error amplification circuit, a power amplification circuit, a current sampling circuit, and a feedback circuit. The error circuit includes a first resistor R1, a first capacitor C1, a second resistor R2, and an amplifier U1. When the pulsed current given signal passes through, the stray signals are filtered out and output to the power amplification circuit; the power amplification circuit includes a totem pole drive circuit composed of a third triode Q3 and a fourth triode Q4, a third resistor R3, and a fourth resistor R4. The voltage signal output by the error circuit is filtered by the third resistor R3 and then amplified by the totem pole drive circuit and flows through the fourth resistor R4 to drive the switching tube S operating in the linear state. Here, the fourth resistor R4 is set to prevent damage to the chip caused by excessive current flow; the current sampling circuit includes a sampling resistor R C , a fourth capacitor C4, and a fifth resistor R5, which are used to convert the pulsed current signal I L on the main circuit into a voltage signal. Among them, the fifth resistor R5 converts the pulsed current signal I L into a voltage signal, and the fourth capacitor C4 removes high-frequency spike interference; the feedback circuit includes a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, which are used to control the output pulsed current to follow the pulsed current given signal Iref. Specifically, the first end of the first resistor R1 is connected to the pulsed current given signal Iref, the second end of the first resistor R1 is connected to the first end of the first capacitor C1 and the first end of the second resistor R2, the second end of the first capacitor C1 is grounded, the second end of the second resistor R2 is connected to the positive input terminal of the amplifier U1, and the negative input terminal of the amplifier U1 is respectively connected to the second end of the second capacitor C2, the second end of the third capacitor C3, the first end of the fourth capacitor C4, and the first end of the fifth resistor R5. The output terminal of the amplifier U1 is respectively connected to the first end of the second capacitor C2 and the first end of the third resistor R3. The second end of the second capacitor C2 is also connected to the second end of the third capacitor C3, the first end of the fourth capacitor C4, and the first end of the fifth resistor R5. The second end of the third resistor R3 is respectively connected to the bases of the third triode Q3 and the fourth triode Q4. The emitters of the third triode Q3 and the fourth triode Q4 are respectively connected to the first end of the third capacitor C3 and the first end of the fourth resistor R4, and the collectors are respectively grounded. The first end of the third capacitor C3 is also connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 is connected to the gate of the switching tube S. The second end of the fifth resistor R5 is respectively connected to the second end of the fourth capacitor C4, the first end of the sampling resistor R C , and the source of the switching tube S. The second end of the sampling resistor R C is grounded, and the drain of the switching tube S is connected to the semiconductor laser load LDA.

[0068] As Figure 3As shown in Fig. (3a), the rising edge of the current pulse waveform mainly depends on the SiC MOSFET, which will affect the controllability, electromagnetic compatibility and output waveform quality of the pulse discharge module. The extreme discharge environment of the subsequent pulse discharge module poses high requirements on the pulse discharge switch. The main discharge SiC MOSFET needs to withstand a high blocking voltage, strong pulse current and high current rising slope. The pulse falling edge is controlled by incorporating a tail-cutting circuit across the two ends of the module. Its working process is as follows: when the pulse switch finishes working, the switch in the tail-cutting circuit starts to work and is connected in parallel across the load, then the energy stored in the distributed capacitance of the circuit and the semiconductor laser will be quickly released, which can effectively reduce the pulse falling edge time. In the tail-cutting circuit, a resistor is connected in series as the energy-absorbing resistor of the absorption circuit. The selected energy-absorbing resistor is a high-power non-inductive ceramic resistor, which is commonly used in high-frequency and high-current pulse circuits, especially in high-energy absorption circuits, and has unique advantages. Its main features are: the inductance in the resistor is very small (<0.1uH), usually one-fortieth of the inductance of other non-inductive resistors, or even less than the inductance parasitic at the two connection terminals of the resistor, so its inductance can be ignored and it can be regarded as non-inductive; it has a high withstand voltage and can be used in high-voltage circuits; it can withstand a high current impact. The resistor is mainly made of inorganic materials and has a relatively large heat capacity. Compared with other types of resistors, it can absorb more electrical energy under the same temperature rise.

[0069] As shown in the appendix Figure 3 As shown in Fig. (3b), where Iref is the pulse current given signal. The specific working principle is as follows: the current signal on the semiconductor laser load LDA is converted into a voltage signal through the sampling resistor Rc, and then this sampling signal is sent back to be subtracted from the pulse current given signal Iref to obtain a deviation signal. Finally, this deviation signal is amplified by the power amplifier circuit and then used to drive the SiC MOSFET. The pulse discharge SiC MOSFET is turned on, and the pulse discharge current is output in the semiconductor laser load LDA.

[0070] The block diagram of the closed-loop control system for pulse discharge is as shown in Figure 3As shown in (3c), its working principle is as follows: First, the stray signals are filtered out by the filter circuit composed of R1 and C1. The voltage output by U1 is conducted to the totem-pole drive circuit composed of Q3 and Q4 through the current-limiting resistor R3. The current signal is amplified by the totem-pole drive circuit, causing the drive voltage VG to gradually increase. When the drive voltage rises to the threshold voltage of the switching transistor S, the switching transistor S starts to conduct and current appears, and the load current IL starts to flow. The pulsed current signal IL on the main circuit is converted into a voltage signal through the sampling resistor Rc, and then, through the feedback loop composed of R5, C4, C3, and C2, the output pulsed current is controlled to follow the pulsed current given signal Iref. As the drive voltage VG gradually increases, the current value flowing through the switching transistor S will also gradually rise to the rated value set by the given signal Iref. This control scheme mainly utilizes the transfer characteristics of the switching transistor. When the drive voltage VG is greater than the threshold voltage of the switching transistor S, the switching transistor S operates in the linear region, and its drain current and the drive voltage VG will show a corresponding linear relationship. Therefore, the waveform of the current flowing through the load can be indirectly controlled by controlling the drive voltage.

[0071] For different loads, the input and output ends of the multi-channel laser repetition-rate pulse power supply circuit are cascaded end to end, that is, the input and output ends of the laser repetition-rate pulse power supply circuit composed of several pre-stage charging power supply modules, energy storage modules, and post-stage drive discharge modules are cascaded end to end to meet the requirements of the system output index. Especially in the laser power supply system for aerospace applications, the output power of the semiconductor laser increases as the output power of the laser repetition-rate pulse power supply increases. Currently, it has gradually developed to increase the output power by connecting the outputs of multiple laser repetition-rate pulse power supplies in parallel and coupling them into a laser beam through optical fibers. As Figure 7 shown, when multiple modules need to be cascaded for output, only the input and output of a single module need to be connected end to end and cascaded together. The range of the output power can be determined by the number of cascaded modules. Each module charges one or more corresponding energy storage capacitors respectively. There is a pulsed power control switch in each module. By sending instructions from the control unit to control the on-off of the switch, the number of modules participating in the work can be controlled, and the output power level can be changed to meet the requirements of the wide-range output of the system. Compared with using a single-channel module, the stress borne by each device in each path is smaller, ensuring the stability and reliability of the power supply.

[0072] Based on the laser repetition-rate pulse power supply circuit provided in the above embodiments, the present application also provides a laser, which uses the above laser repetition-rate pulse power supply circuit, making the laser have the characteristics of small volume, fast speed, high precision, long continuous fault-free working time, and reusability.

[0073] In summary, in view of the requirement for high efficiency of the repetitive pulse power supply, the present invention designs the pre-stage boost conversion circuit, improving the efficiency of the overall repetitive pulse power supply circuit. For the post-stage pulse charge and discharge circuit, capacitive energy storage is adopted to reduce the overall volume. The pre-stage boost circuit adopts the magnetic integration method to reduce the volume. Among them, SiC MOSFETs are used for the control switching tubes, achieving high temperature resistance, high voltage resistance, high frequency and radiation resistance.

[0074] It is easy for those skilled in the art to understand that the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A laser repetition rate pulse power supply circuit, characterized in that, It includes a pre-stage charging power supply module, a post-stage driving and discharging module, and several energy storage modules. The pre-stage charging power supply module is connected to the DC bus terminal that powers it. The post-stage driving and discharging module is connected to the load. The several energy storage modules are connected between the pre-stage charging power supply module and the post-stage driving and discharging module; The pre-stage charging power supply module includes a magnetically integrated CRM-Boost DC-DC topology circuit with two-phase interleaved parallel connection, which boosts the supply voltage and charges the several energy storage modules; The post-stage driving and discharging module includes a capacitive energy storage type pulse discharging topology circuit with a tail-cutting circuit, which obtains energy from the several energy storage modules and outputs a pulsed current with a repeating frequency.

2. The laser repetition rate pulse power supply circuit according to claim 1, wherein The described CRM-Boost DC-DC topology circuit includes a first MOSFET-Q1, a first coupled inductor L1, a first diode D1, a second MOSFET-Q2, a second coupled inductor L2, a second diode D2, a capacitor C0, and a resistor R Ld ; The positive pole of the input terminal V in is respectively connected to the same-named terminals of the first coupled inductor L1 and the second coupled inductor L2. The different-named terminal of the first coupled inductor L1 is respectively connected to the drain of the first MOSFET-Q1 and the positive pole of the first diode D1. The different-named terminal of the second coupled inductor L2 is respectively connected to the drain of the second MOSFET-Q2 and the positive pole of the second diode D2. The negative poles of the first diode D1 and the second diode D2 are respectively connected to one end of the capacitor C0 and the resistor R Ld at one end. The negative pole of the input terminal V in is respectively connected to the source of the first MOSFET-Q1, the source of the second MOSFET-Q2, the other end of the capacitor C0, and the resistor R Ld at the other end.

3. The laser repetition rate pulse power supply circuit according to claim 2, characterized in that, The first MOSFET - Q1 and the second MOSFET - Q2 in the CRM-Boost DC-DC topology circuit are both silicon carbide semiconductor field effect transistors.

4. A laser repetition rate pulse power supply circuit according to claim 2, characterized in that, The input current operating mode of the magnetically integrated CRM-Boost DC-DC topology circuit adopts the critical conduction mode. The waveforms of the driving signals of the first MOSFET - Q1 and the second MOSFET - Q2 have a phase difference of 180°. The waveforms of the inductor currents of the first coupled inductor L1 and the second coupled inductor L2 have a phase difference of 180°; The waveforms of the driving signals of the first MOSFET - Q1 and the inductor current of the first coupled inductor L1 have the same phase. The waveforms of the driving signals of the second MOSFET - Q2 and the inductor current of the second coupled inductor L2 have the same phase.

5. A laser repetition rate pulse power supply circuit according to claim 1, characterized in that, The closed-loop circuit of the post-stage pulsed discharging module includes an error amplification circuit, a power amplification circuit, a current sampling circuit, and a feedback circuit; The error circuit includes a first resistor R1, a first capacitor C1, a second resistor R2, and an amplifier U1. When the pulsed current given signal passes through, it filters out the stray signals therein and outputs to the power amplification circuit; The power amplification circuit includes a totem-pole driving circuit composed of a third triode Q3 and a fourth triode Q4, a third resistor R3, and a fourth resistor R4. The voltage signal output by the error circuit is filtered by the third resistor R3 and amplified by the totem-pole driving circuit and then flows through the fourth resistor R4 to drive the switching tube S; The current sampling circuit includes a sampling resistor R C , a fourth capacitor C4, and a fifth resistor R5, which are used to convert the pulse current signal I L on the main circuit into a voltage signal; The feedback circuit includes a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, which is used to control the output pulsed current to follow the pulsed current given signal Iref.

6. The laser repetition rate pulse power supply circuit according to claim 1, wherein The energy storage module is an electrolytic capacitor.

7. The laser repetition rate pulse power supply circuit according to claim 2, wherein The first diode D1 and the second diode D2 are both fast-recovery diodes.

8. A multi-channel cascaded laser pulse-repetition frequency power supply circuit, characterized in that, For different loads, the input and output ends of the laser repetition rate pulsed power supply circuit according to any one of claims 1 - 7 are cascaded head-to-tail to meet the requirements of the system output index.

9. A laser, characterized in that, It includes the laser repetition rate pulsed power supply circuit according to any one of claims 1 - 8.

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