基于扩频调制策略与无源滤波器相结合的SiC电驱系统电磁干扰噪声协同抑制方法OA

As power electronic power converters move towards higher frequencies,the high du/dt and di/dt generated by SiC MOSFETs can cause severe electromagnetic interference(EMI)issues in motor drive systems.Traditional EMI suppression methods employ two approaches:passive filters and spread-spectrum modulation,which have insufficient suppression bandwidth,bulky filter sizes,and poor system control stability.Balancing the suppression and system control performance is challenging.Therefore,it is essential to integrate the advantages of spread spectrum modulation techniques and passive filters to achieve effective broadband conducted interference suppression in SiC-based drive systems. First,based on the motor drive system's conduction path,the impact of random spread-spectrum modulation strategies on EMI suppression and system control performance is investigated.Through the Fourier transform of a single rectangular pulse,the mechanism of the random switching frequency SVPWM(RSF-SVPWM)strategy is analyzed.The formula shows that factors such as the average switching period,the spread spectrum range,and the random number influence the amplitude of conducted interference.When the switching frequency is fixed,increasing the spread-spectrum range reduces the amplitudes of conducted interference peaks.However,when the spread spectrum range exceeds 50%,residual noise in non-switching frequency harmonic bands begins to accumulate,leading to increased conducted interference amplitudes in the sideband and affecting overall suppression effectiveness. Secondly,a quarter-frequency random spread spectrum modulation strategy(QARSF-SVPWM)is proposed.This method divides the spread-spectrum range into four subintervals to reduce harmonics.Simulation results demonstrate that this strategy reduces the negative impact of the spread-spectrum range on system control performance while maintaining effective EMI suppression. Then,a collaborative EMI noise suppression method for motor drive systems is proposed,combining spread-spectrum modulation with passive filter design.This method integrates the average switching frequency and spread spectrum range into the EMI filter design process.Simulation results demonstrate that the proposed method maintains control performance while significantly reducing EMI noise. Experimental results show that: (1)The QARSF-SVPWM strategy can significantly reduce differential-and common-mode EMI noises across the motor drive system.Compared to the traditional random spread-spectrum modulation,this method minimizes the adverse effects of the spread-spectrum range on system control performance while maintaining EMI suppression. (2)By combining passive EMI filters with the improved random modulation strategy,the filter parameters are optimized.To rationally select the corner frequency of the EMI filter,the filter parameters are based on the given spread-spectrum range and the average switching frequency.Compared to traditional passive EMI filter methods for conducted interference suppression,the proposed approach achieves an additional 5～10 dBμV of noise attenuation for differential-mode interference and approximately 5 dBμV for common-mode interference in the mid-to-low frequency range of 10 kHz to 200 kHz.