磁悬浮开关功放数学模型与控制实现

Mathematical model and control implementation of switching power amplifier in magnetical-levitated system

提出了一种基于数字信号处理器(DSP)的数字开关功率放大器设计方法,采用DSP实现了电流闭环控制算法,产生脉冲宽度调制(PWM)信号驱动功率桥从而实现期望电流,阐明了PWM信号的产生逻辑与不同调制模式下PWM的实现方式.采用傅里叶级数对线圈两端电压进行展开,建立了数字开关功率放大器的等效模型,并进行仿真分析.搭建了数字开关功率放大器实验平台,实验结果验证了提出的设计方法的有效性,且基于等效数学模型的仿真结果与实验结果较为接近,其模型能为功率放大器设计作参考.

Digital switching power amplifier design method based on digital signal processor (DSP) was put forward,in which current closed-loop control algorithm was implemented in DSP and pulse width modulation (PWM)signals were generated to drive power bridge for implementing desired cur-rent.The PWM signal generation logic and implementation in different modulation modes was dis-cussed.Based on equivalent model of switching power amplifier established by the Fourier series ex-pansion of voltage across the coil,simulation analysis was carried on.Experimental platform for digit-al switching amplifier was built for relevant experiment,which proved the validity of the proposed de-sign method.Simulation results based on equivalent mathematical model are close to the experimental results,and it means the model can guide the power amplifier design.