中文说明：随机调制信号下的模拟ppm，pwm整流器的建模仿真，结合PCA的尺度不变特征变换(SIFT)算法，快速扩展随机生成树算法，重要参数的提取，详细画出了时域和频域的相关图。
English Description：
Random modulation signal simulation ppm, the modeling and Simulation of PWM rectifier, combined with PCA scale invariant feature transform (SIFT) algorithm, the rapid expansion of the random spanning tree algorithm, extraction of important parameters, with painting the time domain and frequency domain correlation diagram.