以STC12C5A60S2高性能单片机作为控制核心，设计一种单自由度电流型PWM功率放大器，具有集成度高、体积小和成本优势。霍尔电流传感器完成电流信号到电压信号转换，单片机内部2路10位精度A/D分别采样控制信号和测量信号。离散PI控制器对8位精度PWM模块进行占空比调节，控制电流上升和下降速度。采用Simulink对比仿真了三电平控制策略，测试结果和仿真数据相一致，反映出功率放大器的静态电流精度高、纹波小，动态响应速度可以满足实际应用。从而得出控制策略有效，实现方法可行，系统稳定性好。%A current mode PWM power amplifier with single degree of freedom was designed by taking STC12C5A60S2 high performance microcontroller as the control core,which has the advantages of high integration,small size,and low cost. The Hall current sensor is used to convert the current signal into voltage signal. The 10⁃bit 2⁃channel A/D internal SCM is used to sample the control signal and measurement signal respectively. The discrete PI controller can adjust the duty cycle of PWM module with 8⁃bit precision,and control the current ascent rate and descent rate. The three⁃level control strategy is contrasted and simulated by means of Simulink. The test results and simulation data are consistent,which reflects that the current mode power amplifier has high quiescent current accuracy and small ripple,and the dynamic response speed can meet the practical application. The control strategy is effective,and the implementation method is feasible. The system has good stability.
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