变频器对船舶电网电流谐波影响及抑制方案

Influence of Frequency Converter on Current Harmonics of Propulsion System and Its Control Planning

针对变频调速推进系统对船舶电网电流谐波的影响,通过改变变频器输出功率和输出频率,观察变频器交流侧电网电流谐波的变化规律,详细分析了变频器在交流电网侧产生的间谐波。结果表明,变频器输出功率、输出频率降低,交流电网侧电流谐波畸变率增大;间谐波主要分布于低频段,间谐波频率越低,谐波幅值越大。由此提出了基于无源滤波器、直流侧电容和高通滤波器综合滤波方案,并利用Matlab建立仿真模型进行分析,有效验证了方案的可行性。

Variable-frequency control propulsion system has impact on the current harmonics of ship grid. The output power and output frequency of converter are changed to observe the current harmonics variation on AC grid side of converter. In addition, this paper analyzes the inter-harmonics produced on AC side of grid. The results show that the distortion ratio of current harmonic on AC grid side will increase when the converter decreases output power and output fre- quency; the inter-harmonics are mainly distributed among the low frequencies; with the lower of inter-harmonic frequen- cy, its amplitude is larger. On this basis, we put forward a filtering scheme coupled with passive power filter, DC capacitor and high pass filter. Simulation model with Matlab software verifies the feasibility of the proposed scheme.