基于DSP的数字化控制逆变式空气等离子切割电源研究

Study on air plasma arc cutting inverter power supply with DSP based on digital controller

采用数字信号处理器DSP56F805,建立了逆变式空气等离子切割电源数字化控制系统。利用霍尔电流传感器检测电源输出电流,通过采样与A/D变换、数字滤波和PID控制实现了稳定的恒电流输出特性,并通过大林算法克服了数字PWM控制以及功率变换电路输出本身的延迟效应。此外,电源系统还采用Boost电路进行有源功率因数校正,输入EMI滤波电路滤除高频干扰,从而有效地提高了电源系统的功率因数和工作稳定性,以及数字化控制系统的抗高频干扰能力。实验结果表明,该数字化控制逆变式空气等离子切割电源切割过程稳定,切割质量良好。

The digital control system for air plasma arc cutting inverter power supply has been developed by using digital signal processor DSP56F805.After sampling, A/D conversion and digital filtering on the output current of power supply, which is detected by Hall current sensor,a stable constant current output characteristic is realized via PID control, and the delay effect of digital PWM control and output itself of power converter is overcome via Dalin algorithm.Furthermore,the Boost converter is used for active power factor correction, and input EMI filter is used for eliminating high frequency disturbance in the power supply system, so that the power factor and operational stability of power supply system and the anti-disturbance ability to high frequency noise of digital control system are improved effectively.The experimental results show that the developed air plasma arc cutting inverter power supply with DSP based on digital controller has stable cutting process and good cutting quality.