基于双随机调制的特定频率谐波消除方法研究

Research on specific frequency harmonic elimination method based on dual randomized modulation

为解决随机脉宽调制技术在自主式水下潜航器应用过程中可能引起系统共振的问题,提出基于双随机调制的特定频率谐波消除法。从随机调制导致共振与功率谱的内在联系出发,并依据特定频率处的频谱零点,建立随机脉冲延迟系数、占空比与开关周期的关系,从而实现双随机调制与特定频率谐波消除法的有效结合。经过仿真和实验验证,证明双随机调制特定频率消除法相比单随机调制技术的特定频率谐波消除法在抑制谐波方面更具优势,弥补了单随机调制技术中因开关周期随机性较差而导致的功率谱密度产生谐波峰值的缺点。其在抑制高频噪声的基础上同时消除了特定频率处的谐波,使谐波能量分散更加均匀,有效避免随机调制过程中带来的电机驱动系统共振问题。

In order to solve the problem that the random pulse width modulation technology may cause system resonance in the application of autonomous underwater vehicle,a specific frequency harmonic elimination method based on dual randomized modulation has been proposed in terms of the internal relationship between resonance caused by random modulation and power spectrum.According to the specific frequency spectral nulls,the relationship between random pulse delay coefficient,duty cycle and switching period was established to realize effective combination of dual randomized modulation and specific frequency harmonic elimination method.Through simulation and experimental verification,dual randomized modulation the harmonic suppression effect is better than the specific frequency harmonic elimination method based on single random modulation technology,which is a remedy for the shortcoming of harmonic peak generated by power spectral density due to poor randomness of switching period in single random modulation technology.And on the basis of suppressing high frequency noise,the harmonic at specific frequency was eliminated at the same time,so that the harmonic energy dispersion is more uniform,and the resonance problem of motor drive system caused by random modulation is effectively avoided.