Design Of Driving Power Source For High Power Fiber Laser

Fiber lasers have the advantages of high conversion efficiency,good beam quality,low maintenance cost,and good heat dissipation performance,etc.Especially,high-power fiber lasers are widely used in 3D printing,laser manufacturing and other fields.However,the requirements for the driving power of high-power fiber lasers are relatively high.The price of related products at home and abroad is also relatively higher.In this paper,a fiber laser drive power supply above 2000 W is developed according to the special performances of one company required.The modular design method has been adopted.The prototype of a driving power has advantages such as high efficiency,low cost,high stability and high reliability,etc.The main work is as follows:1.A kind of fiber laser driving power is designed according to the newly developed fiber laser driving power parameters.In order to achieve a stable power output and a large power adjustment range,a constant current module is developed.Each module has a driving power of 750 W and a constant current output falling between 0 A and 15 A.We use the MOSFET to adjust current output based on the voltage-controlled current source.Current output is efficient and stable.In order to improve the stability of the system,high-precision sampling resistor is used to obtain the real-time value of the output signal in the main circuit.Accurate adjustment of the current is achieved by comparing the reference voltage with the feedback unit directly.The voltage between the MOSFET source electrode and the gate electrode is adjusted finely.In order to improve system reliability,the modular design is adopted in hardware circuits.The over-current protection circuit,anti-surge circuit,microprocessor circuit and auxiliary power circuit are also designed according to the parameters required.2.A kind of high-performance processor STM32 is used to the main control chip of the driving power supply,and an automatic control program is developed to protect the load device.The system has two working mode,there are ordinary working mode and highprecision working mode.It could be adapted to different scenarios.A high-precision current control algorithm program is developed in the high-precision working mode,and a precise control of the drive current is accomplished.According to practical applications,the two driving modes can be switched freely.3.In order to meet the actual technical requirements of the driving power,a PI algorithm based on the power supply control system is adopted,and high-precision current control algorithm program is developed.The control signal is limited to prevent the system output current from fluctuating to improve accuracy of current output.Experimental results show that stability of current output is improved by at least 3.12%.Compared to the normal working mode,the accuracy of current output is improved at least 50.88%.The experimental results of the system we developed show that the continuous current output of one module is between 0 A and 15 A,the highest power output is 750 W,the accuracy is 0.1% and ripple coefficient is less than 1%.Current stability coefficient is less than 0.1%.It is obvious that all technical parameters meet or precede the requirements.The designed modules of constant current can be used in parallel,and could be assembled according to different power desired.The system we developed has the advantages of small size,good heat dissipation effect,high accuracy,low cost,etc.