A power supply management method and system applied to a fiber laser pumping source

Abstract

The application provides a power supply management and control method and system applied to a fiber laser pumping source and a fiber laser power supply management and control technical field. The application can accurately identify the current working mode of the pumping source by detecting the pressure difference between the two ends of the linear constant current source and obtaining the constant current source control signal state, and can set the corresponding target pressure difference range according to different working modes, and then adjust the output voltage of the constant voltage source through a closed loop, so that the pressure difference of the constant current source is always kept in a reasonable range. The scheme effectively solves the problem of large range fluctuation of the pressure difference of the constant current source caused by the wide range change of the voltage when multiple pumping sources are connected in series for power supply, reduces the heat dissipation of the constant current source, and improves the overall efficiency of the system.

Description

Technical Field

[0001] This invention relates to the field of power control technology for fiber lasers, and in particular to a power control method and system for a pump source of a fiber laser. Background Technology

[0002] The pump source is the core unit of a fiber laser. As a laser diode, it is typically powered by a constant current source to ensure stable output power and long-term product reliability. With the continuous increase in fiber laser output power, the current required by the pump source also increases. The rated operating current of a high-power fiber laser pump source is generally 40A-50A. Furthermore, to meet the requirements of processing systems, high-power fiber lasers need to rapidly change their output optical power, typically requiring a modulation frequency response of 5kHz. This is generally achieved by controlling the rapid change of the pump source's operating current through electrical modulation. Therefore, the pump source power supply system must simultaneously possess constant current output capability, fast modulation response capability, and high conversion efficiency.

[0003] Currently, the conventional solutions on the market mainly include the following three types. The first solution is to configure a separate high-power constant current source for each fiber laser pump source, and control the output current of each constant current source individually through a control system. While this solution can ensure the power supply stability of each pump source, as the output power of fiber lasers increases and the number of pump sources continues to increase, configuring a separate constant current source leads to a significant increase in the cost and control complexity of the entire system. The second solution is to use a single constant current source to power two or more fiber laser pump sources connected in series simultaneously, in order to reduce system cost. However, the load voltage associated with series pump sources will fluctuate significantly with changes in operating current: for a single pump source operating within the range of 0 to rated current, the associated voltage variation is approximately 5V; when N pump sources are connected in series, the range of associated voltage variation expands to N×5V. With a fixed output voltage from the constant voltage source, the voltage difference across the constant current source will change drastically, causing the constant current source module to overheat severely, making it prone to burnout, and resulting in very low overall efficiency of the power supply system. The third option is to use a constant voltage source with a constant current priority mode to power the pump source. Although this option can solve the efficiency problem to some extent, it cannot meet the frequency response required by the fast electrical modulation of fiber lasers due to its working principle.

[0004] Furthermore, the following voltage relationship exists between the constant voltage source output voltage Vs, the constant current source voltage difference Vds, the pump source accompanying voltage VLd, and the constant current source sampling resistor voltage drop VRS1: Vs = Vds + VLd + VRS1, where VRS1 is negligible relative to other voltage values. This relationship indicates that when Vs is fixed and the pump source operating current changes, causing a large range of changes in VLd, Vds will change in the opposite direction with a constant amplitude, resulting in significant fluctuations in the constant current source's heat dissipation. Therefore, existing technologies lack a power supply management scheme that can maintain constant current output, meet rapid modulation response, and simultaneously maintain a reasonable voltage difference in the constant current source module to improve efficiency when the voltage accompanying a high-power constant current source load changes dynamically and rapidly over a wide range. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a power control method and system for fiber laser pump sources.

[0006] In one aspect, the present invention provides a power supply management method for a pump source of a fiber laser, comprising: acquiring the actual voltage difference across a linear constant current source, the linear constant current source being used to supply power to the pump source of the fiber laser; acquiring the current state of a constant current source control signal, the constant current source control signal including an enable control signal and a current control signal; determining a current operating mode and a target voltage difference range corresponding to the current operating mode based on the current state of the constant current source control signal; determining whether the actual voltage difference is within the target voltage difference range; if the actual voltage difference is not within the target voltage difference range, generating a voltage adjustment signal, the voltage adjustment signal being used to adjust the output voltage of a constant voltage source supplying power to the linear constant current source, so that the actual voltage difference falls within the target voltage difference range.

[0007] In the method provided in this application, obtaining the actual voltage difference across the linear constant current source is fundamental to sensing the operating state of the constant current source. The actual voltage difference directly reflects the voltage margin of the constant current source under the current operating current and load conditions: when the voltage difference is too large, the voltage across the constant current source is too high, the heat dissipation power increases significantly, and the system efficiency decreases; when the voltage difference is too small, the power switching transistor inside the constant current source may enter the saturation region or the cutoff region, failing to maintain constant current output and affecting the power supply stability of the pump source. Obtaining the current state of the constant current source control signal enables the system to identify the current operating condition of the pump source. In actual operation, the pump source can output a constant current continuously, or it can switch and modulate the output at a certain frequency, or it can alternate between two different current values. The requirements for the voltage difference of the constant current source vary under different operating conditions, therefore, it is necessary to determine the corresponding target voltage difference range based on the state of the control signal. The system determines whether the actual pressure difference is within the target pressure difference range. When the actual pressure difference deviates from the target range, a voltage regulation signal is generated. By adjusting the output voltage of the constant voltage source, the pressure difference across the constant current source is brought back to the target range, thus achieving closed-loop adaptive control of the constant current source pressure difference. Through this scheme, even if multiple pump sources are connected in series, causing large variations in the load voltage, the constant current source can always operate within a reasonable pressure difference range by dynamically adjusting the output voltage of the constant voltage source. This avoids the problem of severe overheating due to excessive pressure difference and ensures that the constant current source has sufficient pressure difference margin to maintain constant current output capability. Furthermore, this closed-loop adjustment process does not rely on manual intervention and can quickly respond to changes in the pump source's operating state, meeting the needs of rapid electrical modulation in fiber lasers.

[0008] In some preferred embodiments, determining the current operating mode and the target differential voltage range corresponding to the current operating mode based on the current state of the constant current source control signal includes: if the enable control signal is continuously active and the current control signal is a fixed voltage value, then the current operating mode is determined to be a continuous output mode, and the target differential voltage range corresponding to the continuous output mode is a first differential voltage range; if the enable control signal alternates between active and inactive states at a preset switching frequency and the current control signal is a fixed voltage value, then the current operating mode is determined to be a switching modulation mode, and the target differential voltage range corresponding to the switching modulation mode is a second differential voltage range; if the enable control signal is continuously active and the current control signal alternates between two different voltage values, then the current operating mode is determined to be a current alternating output mode, and the target differential voltage range corresponding to the current alternating output mode is the second differential voltage range. By distinguishing different operating modes and configuring corresponding target differential voltage ranges for each mode, the system can adopt different differential voltage control strategies under both continuous pump source output and fast modulation conditions, taking into account both heat dissipation suppression and dynamic response speed. In continuous output mode, the voltage difference can be kept at a low level, thereby reducing the conduction loss of the constant current source. In switch modulation mode and alternating current output mode, a high voltage difference needs to be maintained to ensure the voltage slew rate at the moment of current switching, and to avoid the current rise time becoming slower due to insufficient voltage difference, which would affect the modulation accuracy.

[0009] In one optional implementation, the first voltage difference ranges from 1V to 3V, and the second voltage difference ranges from 3V to 5V. These numerical ranges are determined based on the saturation voltage drop characteristics of the power switch transistor in a high-power linear constant current source and the modulation response speed requirements: when the voltage difference is below 1V, the power switch transistor may not be able to maintain sufficient dynamic range, making it difficult to guarantee constant current accuracy; when the voltage difference is above 5V, the heat dissipation power of the constant current source increases significantly, reducing the overall system efficiency. Those skilled in the art can select appropriate target values ​​within the above ranges according to the actual device specifications.

[0010] In some preferred embodiments, obtaining the actual pressure difference across the linear constant current source includes: obtaining the actual pressure difference across the linear constant current source through an isolation sampling circuit, and transmitting the actual pressure difference in isolation to the control processing unit. Since the linear constant current source is located in the high-voltage power supply circuit, while the control processing unit is located in the low-voltage control circuit, isolating and transmitting the pressure difference signal from the high-voltage side to the low-voltage side through the isolation sampling circuit ensures the electrical safety of the control system and avoids interference from noise generated by the high-voltage power switch operation on the low-voltage control signal.

[0011] In some preferred embodiments, generating a voltage regulation signal includes: applying the voltage regulation signal to the control terminal of the constant voltage source after isolation conversion, so as to adjust the output voltage of the constant voltage source. The output voltage control terminal of the constant voltage source is also located on the high-voltage side. The low-voltage control signal output by the control processing unit is isolated and transmitted to the constant voltage source control terminal through an isolation conversion circuit, thereby achieving safe isolation between the low-voltage control loop and the high-voltage power loop and avoiding the impact of high-voltage side faults on the low-voltage control system.

[0012] In some preferred embodiments, the method further includes: pre-determining the expected voltage difference across the linear constant current source under different output currents based on the number of pump sources connected in series and the volt-ampere characteristics of the pump sources; determining the current output current value based on the current control signal; determining the deviation between the actual voltage difference and the expected voltage difference based on the current output current value and the expected voltage difference; if the deviation value is greater than a preset alarm threshold, determining that the pump source is malfunctioning, outputting an alarm signal, and cutting off the current output of the pump source. By pre-setting the number of pump sources connected in series and their volt-ampere characteristics, the system can calculate the expected voltage difference that should be presented across the constant current source based on the current output current value, and then compare the real-time detected actual voltage difference with the expected voltage difference. When the volt-ampere characteristics of the pump source change due to aging, performance drift, or damage, the actual voltage difference will deviate from the expected value. By comparing the deviation value, an alarm signal can be issued in time and the current output can be cut off before the fault worsens, realizing automatic protection against malfunctions of multiple pump sources connected in series.

[0013] In some preferred embodiments, the linear constant current source is a linear voltage-controlled constant current source, including a power switch, an operational amplifier, and a sampling resistor. The output current of the linear voltage-controlled constant current source is linearly proportional to the voltage value of the current control signal. This linear voltage-controlled constant current source utilizes the feedback characteristics of the operational amplifier in conjunction with the power switch to form a closed-loop negative feedback structure. The sampling resistor converts the output current into a voltage signal and feeds it back to the input of the operational amplifier, enabling the output current to accurately track changes in the current control signal. This results in advantages such as fast response speed, low output ripple, and high constant current accuracy.

[0014] On the other hand, the present invention also provides a power management system for a fiber laser pump source, comprising: a differential pressure detection module for acquiring the actual differential pressure across a linear constant current source, the linear constant current source being used to power the fiber laser pump source; a control signal detection module for acquiring the current state of a constant current source control signal, the constant current source control signal including an enable control signal and a current control signal; a mode determination module for determining the current operating mode and the target differential pressure range corresponding to the current operating mode based on the current state of the constant current source control signal; a judgment module for judging whether the actual differential pressure is within the target differential pressure range; and a voltage adjustment module for generating a voltage adjustment signal when the actual differential pressure is not within the target differential pressure range, the voltage adjustment signal being used to adjust the output voltage of the constant voltage source supplying power to the linear constant current source, so that the actual differential pressure falls within the target differential pressure range. Through the coordinated operation of the above modules, the system can maintain a reasonable differential pressure of the constant current source in real time under different operating conditions and different operating currents of the pump source, ensuring efficient and stable operation of the power supply system.

[0015] The present invention has the following beneficial effects: This invention accurately identifies the current operating mode of the pump source by real-time detection of the voltage difference across a linear constant current source and obtaining the constant current source control signal status. It then sets corresponding target voltage difference ranges for different operating modes and adjusts the constant current source output voltage through a closed-loop system to ensure the constant current source voltage difference remains within a reasonable range. This solution effectively solves the problem of large-range fluctuations in constant current source voltage difference caused by wide voltage variations when multiple pump sources are connected in series, reduces heat dissipation of the constant current source, and improves the overall system efficiency.

[0016] This invention, by detecting the constant current source control signal, can quickly identify changes in operating conditions when the pump source is switched and modulated at a certain frequency or outputs current alternately, and adjust the constant voltage source output voltage accordingly, thus meeting the frequency response requirements of the fiber laser's rapid electrical modulation and ensuring the stable operation of the power supply system under dynamic conditions.

[0017] This invention, by presetting the pump source voltage-current characteristics and monitoring the differential pressure deviation, can promptly issue an alarm and cut off the current output when the pump source operating characteristics change abnormally. This achieves automatic protection against abnormal operation of multiple series pump sources, improving the safety and reliability of fiber lasers during long-term operation. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the intelligent adaptive power management system for fiber laser pump sources according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a high-power linear voltage-controlled constant current source according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In high-power fiber laser applications, the power supply stability of the pump source directly determines the laser's output quality and lifespan. The pump source is a laser diode, and its forward voltage drop changes with the operating current; this forward voltage drop is the accompanying voltage during pump source operation. When multiple pump sources are connected in series and powered by the same constant current source, the change in accompanying voltage will linearly increase with the number of pump sources connected in series. If the output voltage of the constant current source cannot dynamically adjust to the changes in accompanying voltage, the voltage difference across the constant current source will fluctuate significantly, causing drastic changes in the heat dissipation power of the constant current source module. This can reduce power conversion efficiency or even burn out the constant current source components. The power management scheme provided in this application dynamically adjusts the output voltage of the preceding constant current source by real-time detection of the voltage difference across the constant current source and combining this with the constant current source control signal status to ensure the constant current source always operates within a reasonable voltage difference range. This satisfies the requirements for constant current output and rapid modulation while suppressing heat dissipation and improving system efficiency.

[0022] In this embodiment, a linear constant current source refers to a constant current source circuit operating in the linear amplification region, where the output current is linearly proportional to the input control voltage. Its specific implementation includes, but is not limited to, a linear voltage-controlled constant current source based on a power switch and an operational amplifier. The actual voltage difference refers to the voltage difference between the input and output terminals of the linear constant current source, i.e., the voltage that the linear constant current source itself withstands. This voltage is directly related to the heat dissipation power of the constant current source. The accompanying voltage refers to the voltage drop between the positive and negative terminals of the pump source laser diode under operating current. The target voltage difference range refers to the preset voltage difference interval under different operating modes to ensure that the constant current source meets both constant current accuracy and reasonable heat dissipation. Its upper limit is usually determined by heat dissipation power constraints, and its lower limit is determined by the saturation voltage drop of the power switch and the required dynamic voltage slew rate. The constant current source control signal includes two parts: an enable control signal and a current control signal. The enable control signal is used to control the output enable state of the constant current source, and the current control signal is used to control the magnitude of the output current of the constant current source.

[0023] Reference Figure 1 The power management system provided in this application includes a constant voltage source, a linear constant current source, a pump source load, an isolation voltage control module, an isolation differential voltage detection module, a control processing unit (MCU processing unit), an enable control signal (constant current source enable switch control signal), and a current control signal (e.g., controlling the voltage of the constant current source output current). The constant voltage source is an adjustable DC output constant voltage source, whose input terminal is connected to the AC power grid, and whose output terminal is connected to the power input terminal of the linear constant current source. The output voltage of the constant voltage source is controlled by the voltage adjustment signal output by the control processing unit through the isolation voltage control module. In this application embodiment, the output voltage of the constant voltage source is referred to as the constant voltage source voltage Vs. The input terminal of the linear constant current source is connected to the output terminal of the constant voltage source, and the output terminal of the linear constant current source is connected to the pump source load. The linear constant current source is used to convert the DC voltage output by the constant voltage source into a constant DC current to power the pump source load. The pump source load consists of one or more fiber laser pump sources connected in series, each pump source being a laser diode. The input of the isolated differential pressure detection module is connected to the two voltage detection terminals of the linear constant current source, and the output is connected to the analog input terminal of the control processing unit. This module acquires the actual differential pressure Vds across the linear constant current source and transmits the signal to the control processing unit after electrical isolation. The input of the isolated voltage control module is connected to the control output terminal of the control processing unit, and the output is connected to the voltage control terminal of the constant voltage source. This module applies the voltage adjustment signal output by the control processing unit to the control terminal of the constant voltage source after electrical isolation to adjust its output voltage. The enable control signal and current control signal are connected to the digital input terminal and analog input terminal of the control processing unit, respectively. The enable control signal controls the enable state of the linear constant current source, and the current control signal controls the output current of the linear constant current source.

[0024] In one embodiment, the enable control signal is a digital level signal. When it is at a high level, the linear constant current source is allowed to output current, and when it is at a low level, the linear constant current source is turned off. The current control signal is an analog voltage signal. The larger the voltage value, the larger the output current of the linear constant current source.

[0025] In this embodiment, the control processing unit is an MCU microcontroller, which integrates an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC). The control processing unit receives the differential pressure signal output from the isolated differential pressure detection module and the voltage value of the current control signal via the ADC, receives the level state of the enable control signal via the digital input pin, and outputs an analog voltage signal to the isolated voltage control module via the DAC. In this embodiment, the specific isolation method between the isolated differential pressure detection module and the isolated voltage control module can be optocoupler isolation or magnetic isolation; this embodiment is not limited to this. The purpose of adopting the isolation scheme is that the constant voltage source, linear constant current source, and pump source load constitute a high-voltage power circuit, while the control processing unit belongs to a low-voltage control circuit. The isolation device can block the destructive transmission of high-voltage side faults to low-voltage devices, and simultaneously suppress common-mode interference generated by the high-frequency operation of power switching devices from entering the control circuit.

[0026] Reference Figure 2The circuit implementation of the linear constant current source includes a power switch Q1, an operational amplifier U2A, an analog switch U1, a sampling resistor RS1, resistors R1, R2, R3, and R4. The drain of the power switch Q1 is connected to the positive output terminal of the constant voltage source. The source of the power switch Q1 is connected to the positive terminal (LD+) of the pump source load via the sampling resistor RS1, and the negative terminal (LD-) of the pump source load is connected to the negative output terminal of the constant voltage source. The non-inverting input of the operational amplifier U2A is connected to the current control signal, and the inverting input of the operational amplifier U2A is connected to the common terminal of the sampling resistor RS1 and the source. The output of the operational amplifier U2A is connected to the gate of the power switch Q1 via resistor R1. The analog switch U1 is connected between the output of the operational amplifier U2A and the gate of the power switch Q1, and the switching state of the analog switch U1 is controlled by an enable control signal. Resistor R2 is connected between the gate and source of power switch Q1 to provide a gate discharge path; resistors R3 and R4 form a voltage divider connection to set the operating point of operational amplifier U2A. The linear constant current source works as follows: When the enable control signal is high, analog switch U1 is turned on, and the output voltage of operational amplifier U2A is applied to the gate of power switch Q1 through resistor R1, turning on power switch Q1. Due to the closed-loop negative feedback of operational amplifier U2A, the voltage across sampling resistor RS1 is controlled to be equal to the voltage value of the current control signal. Therefore, the current through the pump source load is equal to the ratio of the voltage value of the current control signal to the resistance value of sampling resistor RS1, meaning the output current is linearly proportional to the voltage value of the current control signal. When the enable control signal is low, analog switch U1 is turned off, the gate of power switch Q1 discharges charge through resistor R2, power switch Q1 is turned off, and the constant current source has no current output. The operating voltage difference Vds across the linear constant current source is the potential difference between the Vs+ and Vs- terminals, which is the constant voltage source output voltage Vs minus the accompanying voltage VLd of the pump source load, and then minus the voltage VRS1 across the sampling resistor RS1. Since the resistance of VRS1 is very small, it can be ignored in the analysis; therefore, Vds is approximately equal to Vs minus VLd. From this relationship, it can be seen that, with Vs constant, the smaller VLd is, the larger Vds is, and the greater the power dissipation of the linear constant current source, which is consistent with the analysis in the background section above.

[0027] This invention provides a power supply control method for a pump source of a fiber laser, comprising the following steps: Step S100, obtaining the actual voltage difference across a linear constant current source; Step S200, obtaining the current state of the constant current source control signal; Step S300, determining the current operating mode and target voltage difference range based on the current state of the constant current source control signal; Step S400, determining whether the actual voltage difference is within the target voltage difference range; Step S500, if the actual voltage difference is not within the target voltage difference range, generating a voltage adjustment signal and adjusting the output voltage of the constant voltage source.

[0028] The core of the method provided in this application embodiment lies in sensing the differential pressure state of the constant current source in real time and identifying the current operating mode of the pump source, thereby determining a differential pressure control target that matches the current operating condition, and finally stabilizing the differential pressure of the constant current source within the target range by adjusting the output voltage of the constant current source through closed-loop regulation. The above five steps constitute a complete closed-loop control loop: step S100 provides feedback, step S200 provides operating condition information, step S300 sets the control target according to the operating condition, step S400 performs deviation judgment, and step S500 outputs control quantity. This closed-loop control structure ensures that no matter how the accompanying voltage of the pump source changes with the operating current, the differential pressure across the constant current source can always converge to the preset target range. Compared with the conventional fixed output voltage power supply method, the solution of this application embodiment has significant adaptability advantages in scenarios with a large number of series pump sources and a large range of accompanying voltage changes, avoiding the risk of thermal runaway of the constant current source due to excessive differential pressure, while ensuring that the constant current source has sufficient voltage margin when the current changes rapidly, thus taking into account both system efficiency and dynamic response performance.

[0029] The steps in the above method are explained in detail below.

[0030] For step S100, the actual voltage difference across the linear constant current source is obtained. This actual voltage difference refers to the voltage difference between the input and output terminals of the linear constant current source, and is a direct physical quantity reflecting the heat dissipation state of the constant current source. In the hardware implementation, an isolated voltage difference detection module is connected to the two voltage detection terminals of the constant current source, namely Vs+ and Vs-. The isolated voltage difference detection module samples the voltage difference between the two terminals, and the sampling result is isolated and output to the ADC pin of the control processing unit. The control processing unit reads the voltage difference signal in each control cycle, and obtains the current actual voltage difference Vds after analog-to-digital conversion. Since the constant current source operates in a high-power switching power supply environment, the voltage at its detection point contains a large common-mode voltage component and switching noise. Therefore, using an isolated voltage difference detection module can not only complete the signal transmission from the high-voltage side to the low-voltage side, but also effectively suppress the influence of common-mode interference on the measurement accuracy.

[0031] In specific implementations, the isolation differential pressure detection module of this application embodiment can adopt an isolation sampling circuit composed of a linear optocoupler and an operational amplifier, or a magnetically isolated isolation amplifier, or other analog isolation devices that can achieve electrical isolation and have linear transmission characteristics. This application embodiment does not limit this. The sampling bandwidth of the isolation differential pressure detection module should not be lower than the upper limit of the modulation frequency of the linear constant current source to ensure that the differential pressure sampling value can reflect the transient change trend of the differential pressure during the rapid modulation of the pump source. Since the output terminal of the isolation differential pressure detection module is usually equipped with a low-pass filter, the output differential pressure signal is actually the average differential pressure within a certain time window. Therefore, the actual differential pressure obtained in step S100 can be understood as the equivalent differential pressure value characterizing the average level of heat dissipation of the constant current source. For the control objective of this application embodiment, using the average differential pressure as the control feedback quantity can effectively avoid the modulation frequency component from introducing disturbances into the differential pressure control loop, so that the control loop only responds to the average change trend of the pump source's accompanying voltage, thereby ensuring the stability of the loop.

[0032] In practice, when the pump source operating current continuously varies between zero and the rated current, the DC component of the accompanying voltage changes accordingly, and the average value of the actual voltage difference also changes accordingly. The control processing unit can track this average change on a time scale of several modulation cycles and adjust the output voltage of the constant voltage source to achieve adaptive adjustment of the voltage difference. This control method does not require sensing instantaneous changes in the pump source current, can achieve efficient tracking of the constant voltage source output voltage with a low control bandwidth, and will not interfere with the pump source's fast current modulation function.

[0033] For step S200, the current state of the constant current source control signal is acquired. The constant current source control signal includes an enable control signal and a current control signal, wherein the enable control signal is a digital level signal and the current control signal is an analog voltage signal. The control processing unit detects the level state of the enable control signal through the digital input pin and acquires the voltage value of the current control signal through the ADC channel.

[0034] In practical systems, the enable control signal and current control signal are generated by the main control system of the fiber laser. The main control system generates the corresponding control signals based on the laser's operating timing and power requirements. The level state and high-low level switching frequency of the enable control signal reflect whether the pump source is in continuous operation, switching modulation, or off state; the voltage value and fluctuation pattern of the current control signal reflect the magnitude of the pump source's output current and whether it involves alternating switching of multiple current stages. The control processing unit samples the above two signals at a fixed period, which should be determined based on the highest modulation frequency of the pump source.

[0035] The control processing unit internally buffers the signal states sampled multiple times. By analyzing the signal change patterns within the buffer window, it extracts characteristic information representing the working mode, including whether the enable control signal is continuously active, whether the enable control signal has periodic high-low level alternation, whether the current control signal is a fixed voltage value, and whether the current control signal alternates between two voltage values.

[0036] In specific implementation, the continuous effective state of the enable control signal means that the enable control signal remains at an effective level for a period of time longer than a predetermined time threshold, which can be set to several modulation cycles; the alternating change of the enable control signal at a preset switching frequency means that the enable control signal periodically switches between effective and ineffective levels at a certain frequency and duty cycle, and this switching frequency is the switching modulation frequency of the pump source current; the fixed voltage value of the current control signal means that the voltage fluctuation amplitude of the current control signal does not exceed a preset fluctuation threshold within the sampling window; the alternating change of the current control signal between two different voltage values ​​means that the current control signal switches between high and low voltage values ​​at a certain frequency within the sampling window, corresponding to the alternating output state of the pump source between two different current magnitudes.

[0037] For step S300, based on the current state of the constant current source control signal, the current operating mode and the corresponding target differential pressure range are determined. After acquiring the state characteristics of the enable control signal and the current control signal, the control processing unit determines the current operating mode of the pump source according to the preset mode determination rules, and retrieves the corresponding target differential pressure range based on the operating mode.

[0038] In this embodiment, the operating modes include continuous output mode, switching modulation mode, and alternating current output mode. Specifically, when the enable control signal is continuously active and the current control signal is a fixed voltage value, the current operating mode is determined to be continuous output mode. In this mode, the pump source continuously emits light with a constant current. The constant current source does not need to frequently switch currents in this mode, so the target voltage difference range can be set to a lower first voltage difference range to reduce the heat dissipation loss of the constant current source. When the enable control signal alternates between active and inactive states at a preset switching frequency and the current control signal is a fixed voltage value, the current operating mode is determined to be switching modulation mode. In this mode, the pump source performs switching operations at a certain frequency and duty cycle. In this mode, the constant current source needs to switch rapidly between current output and zero current output. To ensure sufficient voltage slew rate on the rising and falling edges of the current, the target voltage difference range should be set to a higher second voltage difference range. When the enable control signal is continuously active and the current control signal alternates between two different voltage values, the current operating mode is determined to be the alternating current output mode. In this mode, the pump source alternates between two different current values. Similarly, the constant current source needs to quickly switch between the two current levels, and the target differential voltage range is set to the second differential voltage range. The above mode determination rules can be implemented through a state machine or feature recognition software module within the control processing unit.

[0039] In specific implementation, the control processing unit first determines the state of the enable control signal: if the enable control signal is always at an effective level, it further determines the form of the current control signal; if the current control signal is a fixed voltage value, it is determined to be a continuous output mode; if the current control signal alternates between two voltage values, it is determined to be a current alternating output mode; if the enable control signal alternates between high and low levels, it further determines the form of the current control signal; if the current control signal is a fixed voltage value, it is determined to be a switching modulation mode. For complex operating conditions such as simultaneous rapid changes in the enable control signal and the current control signal, the control processing unit can make a determination according to preset priority rules, which is not limited in this embodiment.

[0040] For step S400, it is determined whether the actual voltage difference is within the target voltage difference range. The control processing unit compares the actual voltage difference Vds obtained in step S100 with the target voltage difference range determined in step S300. If the actual voltage difference Vds is within the target voltage difference range, it indicates that the current voltage difference state of the linear constant current source meets the normal operation requirements of this working mode, and there is no need to adjust the output voltage of the constant voltage source. The control processing unit will maintain the current voltage regulation signal unchanged. If the actual voltage difference Vds is higher than the upper limit of the target voltage difference range, it indicates that the voltage difference across the linear constant current source is too large, the constant current source bears too much voltage margin, and the heat dissipation power is too high. At this time, it is necessary to reduce the output voltage of the constant voltage source to reduce the voltage difference. If the actual voltage difference Vds is lower than the lower limit of the target voltage difference range, it indicates that the voltage difference across the linear constant current source is too small, and the constant current source may not have enough voltage margin to maintain constant current output. Especially in the case where the pump source current needs to rise rapidly, insufficient voltage difference will cause the current rise time to slow down or even the constant current to fail. At this time, it is necessary to increase the output voltage of the constant voltage source to increase the voltage difference. In practice, to overcome the influence of residual ripple components in the differential pressure sampling signal on the judgment result, the control processing unit can adopt a hysteresis comparison strategy when comparing. That is, it is judged as too high only when the differential pressure is higher than the upper limit by a preset hysteresis amount, and it is judged as too low only when the differential pressure is lower than the lower limit by a preset hysteresis amount, thereby avoiding frequent switching of the control loop near the critical point.

[0041] For step S500, if the actual pressure difference is not within the target pressure difference range, a voltage adjustment signal is generated. This voltage adjustment signal is used to adjust the output voltage of the constant voltage source supplying power to the linear constant current source so that the actual pressure difference falls within the target pressure difference range. The control processing unit generates the corresponding voltage adjustment signal based on the determination result of step S400.

[0042] Specifically, if the actual voltage difference is higher than the upper limit of the target voltage difference range, a voltage regulation signal is generated to reduce the output voltage of the constant voltage source; if the actual voltage difference is lower than the lower limit of the target voltage difference range, a voltage regulation signal is generated to increase the output voltage of the constant voltage source. The voltage regulation signal is calculated digitally within the control processing unit, converted to an analog voltage by a DAC, and then output to the isolated voltage control module. The isolated voltage control module then converts the signal and applies it to the voltage control terminal of the constant voltage source. The constant voltage source is a high-power switching power supply with adjustable output voltage. After receiving the voltage regulation signal, its voltage control terminal adjusts the duty cycle of the power switching transistor through an internal feedback loop, thereby regulating the output voltage to the target value.

[0043] In terms of adjustment strategy, the control processing unit can adopt a step-approximation method, that is, apply a step increment to the voltage adjustment signal each time, and compare again after the constant voltage source output voltage stabilizes and the differential pressure sampling value is updated. Through multiple iterations, the actual differential pressure gradually converges to the target differential pressure range. Alternatively, a proportional-integral adjustment method can be adopted, which directly calculates the adjustment amount of the voltage adjustment signal based on the magnitude of the differential pressure deviation, so that the differential pressure quickly approaches the target range.

[0044] In practical implementation, since the constant voltage source is a high-power switching power supply module, its output voltage adjustment process has a certain response delay. Therefore, the control processing unit needs to wait for a preset stabilization time after each adjustment before performing the next voltage difference sampling and comparison. This stabilization time can be configured according to the voltage adjustment response time constant of the constant voltage source, and this application embodiment does not limit it.

[0045] When the pump source operating current changes continuously, steps S100 to S500 are continuously executed in a loop, forming real-time dynamic tracking of the constant voltage source output voltage, ensuring that the voltage difference of the linear constant current source remains within a reasonable range throughout the entire operating current range. In specific implementation, for large-scale step changes in the pump source from zero current to rated current, the constant current source voltage difference will decrease rapidly as the accompanying voltage increases. Once the control processing unit detects that the voltage difference is below the lower limit of the target range, it immediately increases the voltage regulation signal, causing the constant voltage source output voltage to rise rapidly, and the voltage difference recovers to the target range within several control cycles. For step changes in the pump source from rated current to zero current, the accompanying voltage decreases rapidly, and the constant current source voltage difference will increase transiently. Once the control processing unit detects that the voltage difference is above the upper limit of the target range, it decreases the voltage regulation signal, causing the constant voltage source output voltage to decrease, and the voltage difference recovers to the target range. Through this closed-loop regulation mechanism, the linear constant current source does not need to withstand large voltage fluctuations, and its power switch always operates at a suitable voltage and current operating point, effectively suppressing heat dissipation.

[0046] To further improve the response speed of voltage regulation, in one optional implementation, the control processing unit can also perform feedforward regulation based on the changing trend of the current control signal. Specifically, when the current control signal is detected to switch from a low voltage value to a high voltage value, it is predicted that the pump source will enter a high-current operating state, accompanied by a voltage increase and a decrease in the constant current source voltage difference. Therefore, the voltage regulation signal is increased in advance at the moment the switch is detected, causing the output voltage of the constant voltage source to rise in advance. After the actual change in voltage difference occurs, only a small closed-loop correction is needed to reach the target range. This control method combining feedforward and feedback can further reduce the voltage difference fluctuation amplitude and adjustment time during large changes in pump source current.

[0047] In the above steps, the differential pressure information and control signal status information acquired in steps S100 and S200 together constitute the input basis for the control processing unit to judge the working status and perform closed-loop adjustment. Step S300 establishes a control target based on the identification result of step S200, step S400 compares the feedback quantity of step S100 with the control target of step S300, and step S500 performs adjustment when a deviation exists. The data flow relationship between the five steps is as follows: the differential pressure detection data stream and the control signal status data stream converge in the control processing unit, output the target differential pressure range after pattern determination logic processing, output the voltage adjustment command after deviation comparison logic processing, and finally act on the voltage control terminal of the constant voltage source. There is no isolated relationship between the steps, but rather they form a complete signal chain with unidirectional information flow and step-by-step transmission of control effect. The method of this embodiment is implemented in the control processing unit through a firmware program, which runs in a periodic interrupt mode. In each interrupt cycle, the above five steps are executed sequentially. The length of the interrupt cycle can be configured according to the system sampling delay and control bandwidth requirements.

[0048] To maintain the stability of the constant current source differential pressure when the pump source is switched and modulated at a certain frequency and duty cycle, in one optional implementation, the differential pressure detection and control by the control processing unit in the switching modulation mode can adopt a modulation cycle synchronization method. Specifically, the control processing unit determines the starting boundary of the modulation cycle based on the level switching time of the enable control signal, samples the differential pressure during the effective conduction period of each modulation cycle, and uses the average value of the sampled values ​​in multiple consecutive modulation cycles as the current actual differential pressure for comparison in step S400. Since the constant current source differential pressure in the switching modulation mode has transient differences during the conduction and turn-off periods, synchronous sampling can obtain a stable differential pressure characterization value during the conduction period, avoiding the acquisition of non-representative instantaneous differential pressure at the signal switching edge.

[0049] In practice, the control processing unit can trigger ADC sampling at the rising edge of the enable control signal, and sample once in each of the conduction intervals corresponding to multiple consecutive rising edges. The arithmetic mean of the sampling results is then used as the actual differential pressure feedback value.

[0050] To precisely control the constant current source differential pressure of the pump source under different operating modes, in one optional embodiment, the target differential pressure range in step S300 is set differently depending on the operating mode. For continuous output mode, the target differential pressure range is set to a first differential pressure range; for switching modulation mode and alternating current output mode, the target differential pressure range is set to a second differential pressure range. The first and second differential pressure ranges are preset control parameters in the control processing unit and can be modified through the parameter configuration interface. By configuring different target differential pressure ranges for different operating modes, the system can pursue the lowest heat dissipation and the highest conversion efficiency in continuous output mode, while balancing fast current response capability and acceptable loss level in modulation mode.

[0051] In specific implementation, the first voltage difference range can be 1V to 3V, and the second voltage difference range can be 3V to 5V. The selection of the above numerical ranges is based on the following: When the power switch Q1 in the linear constant current source is outputting a constant current, a certain voltage margin needs to be maintained between its source and drain to keep the power switch working in the amplification region. When the voltage difference is lower than 1V, the voltage margin of the power switch Q1 is insufficient, which may lead to the output current not being accurately controlled and the constant current accuracy decreasing. When the voltage difference is higher than 5V, the voltage drop across the power switch Q1 is too large, and the heat dissipation power increases significantly. Calculated with a rated current of 50A, a 5V voltage difference corresponds to a dissipation power of 250W, which exceeds the continuous dissipation capacity of the power switch under conventional heat dissipation conditions. Therefore, it should not be higher than 5V. For continuous output mode, the pump source current remains constant, and there are no rapid transient changes in current. The voltage difference only needs to meet the minimum margin required for the normal operation of the power switch, so it can be set in a lower range of 1V to 3V to further reduce heat dissipation. For switching modulation mode and alternating current output mode, the pump source current needs to rise and fall rapidly in a short time. If the voltage difference is too small, it will limit the rate of current change. Therefore, it needs to be maintained in a higher range of 3V to 5V. Those skilled in the art will understand that the above numerical ranges are specific examples given in the embodiments of this application. In actual applications, they can be adjusted according to the device specifications of the constant current source, the number of pump sources in series, and the heat dissipation conditions. The embodiments of this application do not limit this.

[0052] To achieve safe isolation between the high-voltage power circuit and the low-voltage control circuit, in an optional embodiment, the process of obtaining the actual voltage difference across the linear constant current source in step S100 specifically includes: obtaining the actual voltage difference across the linear constant current source through an isolation sampling circuit, and transmitting the actual voltage difference in isolation to the control processing unit. The core component of the isolation sampling circuit is an isolation amplifier or a linear optocoupler, whose input terminal is connected to the two detection terminals of the constant current source, namely Vs+ and Vs-, and whose output terminal is connected to the ADC input pin of the control processing unit. The input and output sides of the isolation sampling circuit have electrical isolation characteristics and can withstand a certain isolation withstand voltage level.

[0053] In practical implementation, the isolation sampling circuit can use a voltage divider resistor network at the input to proportionally attenuate the voltage difference between Vs+ and Vs- to the allowable range of the isolation amplifier input, before linearly transmitting the signal to the output side via the isolation amplifier. Alternatively, a filter circuit and clamping protection circuit can be set on the output side to filter out high-frequency noise and limit the output signal to the allowable voltage range of the ADC input. Since the constant current source operates in a high-voltage, high-current environment, the common-mode voltage at its differential voltage detection points is relatively high. Therefore, the selection of the isolation sampling circuit needs to consider the common-mode rejection ratio (CMRR) to ensure accurate detection of the differential voltage signal even under high CMRR. In practical implementation, the output voltage of the constant voltage source may reach tens to hundreds of volts. When using an isolation amplifier, its CMRR can reach over 100dB, which can meet the accuracy requirements of differential voltage detection.

[0054] To safely transmit the low-voltage control signal output by the control processing unit to the constant voltage source control terminal on the high-voltage side, in an optional embodiment, the process of generating the voltage adjustment signal in step S500 specifically includes: applying the voltage adjustment signal to the control terminal of the constant voltage source after isolation conversion, so as to adjust the output voltage of the constant voltage source. The core component of the isolated voltage control module is an isolation converter, whose input terminal is connected to the DAC output pin of the control processing unit, and whose output terminal is connected to the voltage control terminal of the constant voltage source.

[0055] In specific implementations, the isolated voltage control module can employ PWM isolation transmission. The control processing unit outputs the voltage regulation signal in PWM duty cycle form, which is then transmitted to the high-voltage side via a digital isolator. The RC low-pass filter on the high-voltage side restores the PWM signal to a DC voltage, which is then applied to the voltage control terminal of the constant voltage source. Alternatively, the isolated voltage control module can use a linear isolation amplifier, directly transmitting the analog voltage signal to the high-voltage side via a linear optocoupler or magnetic isolation amplifier. PWM isolation offers advantages such as simple circuitry, strong anti-interference capability, and accuracy unaffected by the nonlinearity of the isolation device, and is therefore preferred in this embodiment. Since the constant voltage source typically integrates a voltage loop feedback control circuit, its voltage control terminal has a high input impedance. Therefore, the output stage of the isolated voltage control module can be equipped with a voltage follower to improve its load-carrying capacity.

[0056] To monitor the operational status of the pump source and provide timely protection in case of abnormal changes in its voltage-current characteristics, in an optional embodiment, the method of this application further includes a step of monitoring and protecting the pump source's operational status. This step specifically includes: pre-determining the expected voltage difference across the linear constant current source under different output currents based on the number of pump sources connected in series and the voltage-current characteristics of the pump sources; determining the current output current value based on a current control signal; determining the deviation between the actual voltage difference and the expected voltage difference based on the current output current value and the expected voltage difference; and if the deviation value exceeds a preset alarm threshold, determining that the pump source is malfunctioning, outputting an alarm signal, and cutting off the current output of the pump source.

[0057] In practical applications, the volt-ampere characteristics of pump sources of the same model typically exhibit good consistency. Based on the datasheet provided by the pump source manufacturer or actual calibration test results, a mapping relationship between the pump source's operating current and its accompanying voltage can be established. For a load with N pump sources connected in series, the total accompanying voltage is N times the accompanying voltage of a single pump source. Combining this with the output voltage of the constant voltage source and the voltage drop across the sampling resistor RS1, the expected voltage difference across the linear constant current source under different output currents can be calculated. The control processing unit stores these expected voltage differences in its internal memory in the form of a lookup table or function curve.

[0058] During operation, the control processing unit periodically maps the currently output current control signal to an output current value, retrieves the corresponding expected differential pressure value from a lookup table, and compares it with the actual differential pressure obtained in step S100. Under normal circumstances, the actual differential pressure should be within the allowable deviation range of the expected differential pressure, indicating that the volt-ampere characteristics of the pump source load conform to the preset characteristics. However, when the pump source experiences aging, performance drift, poor soldering, or device damage, its volt-ampere characteristics will deviate from the original curve, resulting in a significant deviation between the actual and expected differential pressure. When the deviation value exceeds the preset alarm threshold, the control processing unit determines that the pump source is in an abnormal operating state, outputs an alarm signal to the main controller of the fiber laser or the human-machine interface, and simultaneously cuts off the current output of the pump source by controlling the enable control signal or directly disconnecting the constant current source output circuit to prevent further deterioration of the abnormal state. In specific implementations, the value of the preset alarm threshold can be related to the width of the target differential pressure range, and this application embodiment does not limit this. In addition, when the number of pump sources in series changes or when a different model of pump source is replaced, the number of pump sources in series and the volt-ampere characteristic parameters can be updated through the parameter configuration interface to match the lookup table of expected differential pressure with the actual load.

[0059] To further illustrate the specific circuit implementation of the linear constant current source, in one optional embodiment, the linear constant current source is a linear voltage-controlled constant current source, which includes a power switch Q1, an operational amplifier U2A, and a sampling resistor RS1. The output current of the linear voltage-controlled constant current source is linearly proportional to the voltage value of the current control signal. In the specific circuit connection, the power switch Q1 is an N-channel MOSFET, its gate is connected to the output terminal of the operational amplifier U2A through a resistor R1, its drain is connected to the positive output terminal of the constant current source, and its source is connected to the positive terminal LD+ of the pump source load through the sampling resistor RS1. The non-inverting input terminal of the operational amplifier U2A receives the current control signal, and the inverting input terminal is connected to the common terminal of the sampling resistor RS1 and the source of the power switch Q1. When the enable control signal is valid, the analog switch U1 is closed, and the operational amplifier U2A adjusts its output voltage according to the voltage difference between the non-inverting and inverting input terminals, thereby controlling the gate voltage of the power switch Q1, causing a corresponding change in the drain current of the power switch Q1. When the equivalent resistance or accompanying voltage of the pump source load changes, the transient change in output current will cause a change in the voltage across the sampling resistor RS1. This change is quickly corrected by the negative feedback loop of operational amplifier U2A, ultimately making the voltage across the sampling resistor RS1 stably equal to the voltage value of the current control signal. Therefore, the output current value is equal to the ratio of the voltage value of the current control signal to the resistance value of the sampling resistor RS1. The sampling resistor RS1 is a high-power precision resistor with a low temperature coefficient to ensure the long-term stability and temperature stability of the current setting. This circuit structure is a typical closed-loop negative feedback linear constant current control structure. Its response speed is determined by the gain-bandwidth product of operational amplifier U2A and the parasitic capacitance of power switch Q1. By reasonably selecting components, a current modulation bandwidth of several kHz or higher can be achieved, meeting the requirements of fast electrical modulation of fiber laser pump sources.

[0060] In actual operation, the pump source switches between multiple modes depending on the laser's output timing. The system behavior under different operating conditions is explained below.

[0061] When the fiber laser needs to continuously emit light at a constant power, the main control system sets the enable control signal to a continuous high level and the current control signal to a fixed voltage value corresponding to that constant power. At this time, the control processing unit determines that it is currently in continuous output mode and sets the target voltage difference range to 1V to 3V. After the system powers on, the control processing unit first acquires the actual voltage difference and compares it with the 1V to 3V range. If the actual voltage difference is lower than 1V, it indicates that the constant current source's voltage difference margin is insufficient. The control processing unit gradually increases the output voltage of the constant voltage source until the actual voltage difference falls within the 1V to 3V range. If the actual voltage difference is higher than 3V, it indicates that the constant current source is subjected to excessive voltage, resulting in decreased system efficiency. The control processing unit gradually decreases the output voltage of the constant voltage source until the actual voltage difference falls back to the 1V to 3V range. During continuous light emission from the pump source and with a constant operating current, the accompanying voltage of the pump source remains relatively stable, and the output voltage of the constant voltage source remains at a fixed value. The control processing unit only needs to periodically check whether the actual voltage difference is still within the target range.

[0062] When the fiber laser needs to pulse light output at a certain frequency and duty cycle, the main control system sets the current control signal to a fixed voltage value corresponding to the peak power of the pulse output, while the enable control signal alternates between high and low levels at the same frequency. At this time, the control processing unit detects the periodic level switching of the enable control signal, determines that the current operating mode is switch modulation mode, and switches the target voltage difference range to 3V to 5V. In switch modulation mode, the control processing unit sets the target voltage difference to a higher range of 3V to 5V to ensure that the power switch Q1 has sufficient voltage margin to drive the current to build up quickly during the current rise. Because both the enable control signal and the current control signal are in a rapidly changing state in switch modulation mode, the control processing unit filters the sampled voltage difference value, takes the average value over several modulation cycles, and compares it with the target range to avoid erroneous adjustment caused by instantaneous voltage difference fluctuations.

[0063] When the fiber laser needs to rapidly switch between two output powers, the main control system sets the enable control signal to a continuous high level, and the current control signal alternates between two different voltage values ​​at a certain frequency. At this time, the control processing unit determines that the current operating mode is the alternating current output mode and sets the target voltage difference range to 3V to 5V. In the alternating current output mode, the pump source current rapidly switches between two current values; the larger current value corresponds to a higher accompanying voltage, and the smaller current value corresponds to a lower accompanying voltage. The voltage difference across the constant current source will differ between the two current states: the voltage difference is relatively smaller under the larger current state, and relatively larger under the smaller current state. The control processing unit detects the voltage difference under both states individually or in combination. When the voltage difference under either state exceeds the 3V to 5V range, the output voltage of the constant voltage source is adjusted so that the voltage difference under both states is within the target range. Because the accompanying voltages corresponding to the two current states are different, the output voltage of the constant voltage source needs to select a compromise value between them. Under this compromise value, the voltage difference under the larger current state should not be lower than 3V, and the voltage difference under the smaller current state should not be higher than 5V.

[0064] To ensure the safe operation of the system, the method in this application embodiment also includes a safety boundary condition judgment. Before initiating differential pressure regulation, the control processing unit needs to confirm that the output voltage of the constant voltage source is within the safe and permissible regulation range, that is, the output voltage of the constant voltage source does not exceed its rated output voltage upper limit, nor is it lower than the minimum output voltage required to maintain normal system operation. If the voltage regulation signal calculated by the control processing unit has reached the regulation boundary of the constant voltage source, but the actual differential pressure is still not within the target range, it indicates that the voltage regulation capability of the system is insufficient to cope with the current load change. The control processing unit will generate a voltage over-limit alarm and stop further regulation. In addition, during the period when the enable control signal is in an invalid state, that is, when the pump source is in an off state, the linear constant current source is turned off. At this time, the differential pressure state across the constant current source cannot reflect the normal operating characteristics of the pump source load. The control processing unit suspends the differential pressure closed-loop regulation during the period when the enable control signal is invalid, and keeps the current voltage regulation signal unchanged. When the enable control signal becomes valid again and the pump source starts to output current, differential pressure detection and regulation are resumed. By using the above boundary conditions and state judgments, the embodiments of this application can avoid performing meaningless adjustment actions under abnormal working conditions, thus ensuring the stability and safety of the control system.

[0065] Next, a complete workflow of the method in the embodiments of this application will be described. Step S101: The system is powered on and initialized. The control processing unit configures peripheral parameters such as ADC, DAC, and digital input / output, and loads configuration information such as preset operating mode determination rules, target differential voltage range parameters, and pump source volt-ampere characteristic parameters. Step S102: The control processing unit acquires the level state of the enable control signal and the voltage value of the current control signal. Step S103: It is determined whether the enable control signal is in a valid state. If it is in an invalid state, the process returns to step S102 to continue detection; if it is in a valid state, step S104 is executed. Step S104: The form of the current control signal is determined, i.e., whether the current control signal is a fixed voltage value or alternates between two voltage values. Step S105: The current operating mode is determined based on the combination of the states of the enable control signal and the current control signal. If the enable control signal is continuously effective and the current control signal is a fixed voltage value, the operating mode is continuous output mode; if the enable control signal alternates at a preset switching frequency and the current control signal is a fixed voltage value, the operating mode is switch modulation mode; if the enable control signal is continuously effective and the current control signal alternates between two voltage values, the operating mode is alternating current output mode. Step S106: Obtain the corresponding target differential pressure range according to the operating mode. Step S107: Obtain the actual differential pressure across the linear constant current source through the isolated differential pressure detection module. Step S108: Determine whether the actual differential pressure is within the target differential pressure range. If yes, return to step S102 to continue monitoring; if no, proceed to step S109. Step S109: Determine whether the current state is that the enable control signal is effective and has lasted for a sufficient period to eliminate erroneous adjustments under transient conditions. If yes, proceed to step S110. Step S110: Calculate the adjustment amount of the voltage regulation signal based on the differential pressure deviation, and adjust the output voltage of the constant voltage source through the isolated voltage control module. Step S111: Wait for the constant voltage source output voltage to stabilize. Step S112: Return to step S107 to re-detect the actual voltage difference until it falls within the target voltage difference range. Step S113: During pump source operation, periodically monitor the pump source's operating status, comparing the actual voltage difference with the preset expected voltage difference based on the volt-ampere characteristic. If the deviation exceeds the preset alarm threshold, output an alarm signal and cut off the pump source current output. Step S114: The system continues to run, repeating the above monitoring and adjustment process until the system stops operating.

[0066] It should be noted that the order of steps S101 to S114 described above is merely an exemplary process provided in this application embodiment. In actual applications, the execution order of each step can be adjusted according to the specific implementation of the system. For example, the differential pressure detection step S107 can be executed before the mode determination step to reduce the response delay from sampling to adjustment. Those skilled in the art can select a reasonable execution order according to actual needs.

[0067] Corresponding to the above method, this application also provides a power management system for a fiber laser pump source. This system includes a differential pressure detection module, a control signal detection module, a mode determination module, a judgment module, and a voltage regulation module. The differential pressure detection module is used to obtain the actual differential pressure across the linear constant current source; its specific implementation can be found in [reference needed]. Figure 1 The isolation differential pressure detection module includes an isolation sampling circuit and a signal conditioning circuit. The control signal detection module acquires the current state of the constant current source control signal. Its implementation includes a level detection circuit and an analog sampling circuit. The level detection circuit converts the level state of the enable control signal into a digital signal readable by the control processing unit. The analog sampling circuit conditions the voltage value of the current control signal and inputs it to the ADC channel of the control processing unit. The mode determination module determines the current operating mode and the corresponding target differential pressure range based on the current state of the constant current source control signal. Its implementation is a mode determination program running in the control processing unit. The mode determination program analyzes the state of the enable control signal and the form of the current control signal according to preset rules, determines the current operating mode, and retrieves the corresponding target differential pressure range parameters. The judgment module determines whether the actual differential pressure is within the target differential pressure range. Its implementation is a comparison operation logic in the control processing unit, comparing the actual differential pressure value sampled by the ADC with the upper and lower limits of the target differential pressure range. The voltage regulation module generates a voltage regulation signal when the actual pressure difference is not within the target pressure difference range. Its implementation includes a regulation algorithm program in the control processing unit and an isolated voltage control module. The regulation algorithm program calculates the voltage regulation amount based on the pressure difference deviation, and the isolated voltage control module converts the digital voltage regulation signal into an analog signal and transmits it in isolation to the voltage control terminal of the constant voltage source. The signal connections between these modules are as follows: the output of the pressure difference detection module is connected to the inputs of the mode determination module and the judgment module; the output of the control signal detection module is connected to the input of the mode determination module; the output of the mode determination module is connected to the input of the judgment module; the output of the judgment module is connected to the input of the voltage regulation module; and the output of the voltage regulation module is connected to the voltage control terminal of the constant voltage source. During system operation, these modules form a complete closed-loop control link, realizing adaptive adjustment of the constant voltage source output voltage.

[0068] In some embodiments of the above system, the mode determination module is further used to determine the operating mode based on the state of the enable control signal output by the control signal detection module and the shape of the current control signal. Different operating modes correspond to different target voltage difference ranges. Specifically, when the enable control signal is continuously active and the current control signal is a fixed voltage value, the current operating mode is determined to be a continuous output mode, and the corresponding target voltage difference range is the first voltage difference range. When the enable control signal alternates between active and inactive states at a preset switching frequency and the current control signal is a fixed voltage value, the current operating mode is determined to be a switching modulation mode, and the corresponding target voltage difference range is the second voltage difference range. When the enable control signal is continuously active and the current control signal alternates between two different voltage values, the current operating mode is determined to be a current alternating output mode, and the corresponding target voltage difference range is the second voltage difference range. In some embodiments, the first voltage difference range is 1V to 3V, and the second voltage difference range is 3V to 5V.

[0069] In some embodiments of the above system, the system further includes an anomaly monitoring module. This module pre-determines the expected voltage difference across the linear constant current source under different output currents based on the number of fiber laser pump sources connected in series and the pump source's volt-ampere characteristics. It then determines the current output current value based on the current control signal, calculates the deviation between the actual and expected voltage differences based on the current output current and the expected voltage difference, and determines a pump source malfunction when the deviation exceeds a preset alarm threshold. In this case, it outputs an alarm signal and cuts off the pump source's current output. The anomaly monitoring module can share a data path with the voltage difference detection module and the control signal detection module. It runs periodically as a background task within the control processing unit, without affecting the normal execution of the voltage difference closed-loop regulation.

[0070] In some embodiments of the above system, the differential pressure detection module includes an isolation sampling circuit, which is used to transmit the actual differential pressure in isolation to the mode determination module; the voltage regulation module includes an isolation conversion circuit, which is used to apply the voltage regulation signal to the control terminal of the constant voltage source after isolation conversion. The isolation sampling circuit and the isolation conversion circuit respectively realize signal isolation transmission between the high-voltage side and the low-voltage side, ensuring that the system operates safely and reliably between different ground potentials.

[0071] It should also be noted that the series connection of multiple pump sources involved in this application embodiment can be two or more pump sources connected in series. The specific type of pump source can be a single-tube laser diode, a laser diode bar, or a laser diode module, and the specifications of each pump source can be the same or different. The output voltage adjustment range of the constant voltage source needs to cover the voltage variation range accompanying the pump source load across the entire operating current range, with sufficient margin. The constant voltage source can be implemented using an isolated AC-DC switching power supply or a non-isolated DC-DC converter; this application embodiment does not limit this.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power supply control method for a fiber laser pump source, characterized in that, The method includes: The actual voltage difference across the linear constant current source is obtained; the linear constant current source is used to power the pump source of the fiber laser. Obtain the current state of the constant current source control signal, which includes an enable control signal and a current control signal; Based on the current state of the constant current source control signal, determine the current operating mode and the target differential pressure range corresponding to the current operating mode; Determine whether the actual pressure difference is within the target pressure difference range; If the actual pressure difference is not within the target pressure difference range, a voltage adjustment signal is generated. The voltage adjustment signal is used to adjust the output voltage of the constant voltage source supplying power to the linear constant current source so that the actual pressure difference falls within the target pressure difference range.

2. The method according to claim 1, characterized in that, The step of determining the current operating mode and the target differential pressure range corresponding to the current operating mode based on the current state of the constant current source control signal includes: If the enable control signal is continuously active and the current control signal is a fixed voltage value, then the current operating mode is determined to be a continuous output mode, and the target differential pressure range corresponding to the continuous output mode is the first differential pressure range. If the enable control signal alternates between an active state and an inactive state at a preset switching frequency and the current control signal is a fixed voltage value, then the current operating mode is determined to be a switching modulation mode, and the target differential voltage range corresponding to the switching modulation mode is the second differential voltage range. If the enable control signal is continuously active and the current control signal alternates between two different voltage values, then the current operating mode is determined to be the alternating current output mode, and the target differential pressure range corresponding to the alternating current output mode is the second differential pressure range.

3. The method according to claim 2, characterized in that, The first differential pressure range is 1V to 3V, and the second differential pressure range is 3V to 5V.

4. The method according to claim 1, characterized in that, The step of obtaining the actual pressure difference across the linear constant current source includes: obtaining the actual pressure difference across the linear constant current source through an isolation sampling circuit, and transmitting the actual pressure difference to the control processing unit in an isolated manner.

5. The method according to claim 1, characterized in that, The generation of the voltage regulation signal includes: applying the voltage regulation signal to the control terminal of the constant voltage source after isolation and conversion, so as to adjust the output voltage of the constant voltage source.

6. The method according to claim 1, characterized in that, The method further includes: The expected voltage difference across the linear constant current source under different output currents is determined in advance based on the number of pump sources connected in series and the volt-ampere characteristics of the pump sources. The current output current value is determined based on the current control signal; Based on the current output current value and the expected voltage difference, determine the deviation between the actual voltage difference and the expected voltage difference; If the deviation value is greater than the preset alarm threshold, the pump source is determined to be malfunctioning, an alarm signal is output, and the current output of the pump source is cut off.

7. The method according to claim 1, characterized in that, The linear constant current source is a linear voltage-controlled constant current source, which includes a power switch, an operational amplifier, and a sampling resistor. The output current of the linear voltage-controlled constant current source is linearly proportional to the voltage value of the current control signal.

8. A power control system for a fiber laser pump source, characterized in that, The system includes: A differential pressure detection module is used to obtain the actual differential pressure across a linear constant current source, which is used to power the pump source of a fiber laser. A control signal detection module is used to acquire the current state of the constant current source control signal, which includes an enable control signal and a current control signal. The mode determination module is used to determine the current working mode and the target differential pressure range corresponding to the current working mode based on the current state of the constant current source control signal. The judgment module is used to determine whether the actual pressure difference is within the target pressure difference range; A voltage regulation module is used to generate a voltage regulation signal when the actual pressure difference is not within the target pressure difference range. The voltage regulation signal is used to adjust the output voltage of the constant voltage source supplying power to the linear constant current source so that the actual pressure difference falls within the target pressure difference range.

9. The system according to claim 8, characterized in that, The pattern determination module is specifically used for: If the enable control signal is continuously active and the current control signal is a fixed voltage value, then the current operating mode is determined to be a continuous output mode, and the target differential pressure range corresponding to the continuous output mode is the first differential pressure range. If the enable control signal alternates between an active state and an inactive state at a preset switching frequency and the current control signal is a fixed voltage value, then the current operating mode is determined to be a switching modulation mode, and the target differential voltage range corresponding to the switching modulation mode is the second differential voltage range. If the enable control signal is continuously active and the current control signal alternates between two different voltage values, then the current operating mode is determined to be the alternating current output mode, and the target differential pressure range corresponding to the alternating current output mode is the second differential pressure range.

10. The system according to claim 8, characterized in that, The system also includes an anomaly monitoring module, which is used for: The expected voltage difference across the linear constant current source under different output currents is determined in advance based on the number of pump sources connected in series and the volt-ampere characteristics of the pump sources. The current output current value is determined based on the current control signal; Based on the current output current value and the expected voltage difference, determine the deviation between the actual voltage difference and the expected voltage difference; If the deviation value is greater than the preset alarm threshold, the pump source is determined to be malfunctioning, an alarm signal is output, and the current output of the pump source is cut off.

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