船舶电力推进变频输出电压谐波抑制研究

The Output Voltage Harmonics Suppression Research on Ship Electric Propulsion Variable Frequency Driver

根据船舶电力推进变频驱动的特点,提出了一种新型变频器输出混合有源正弦波滤波器,在变频器的输出侧接上一个LC基波串联谐振电路,使变频器的输出电压对基波呈现低电抗、对谐波呈现高阻抗;同时实时检测负载端电压,根据瞬时无功功率理论可直接检测出谐波电压波形,并通过变流器和串联变压器反馈一个与谐波电压幅值相等、相位相反的电压去抵消系统中剩余的谐波电压。阐述了新型变频器输出混合有源正弦波滤波器的结构和工作原理,分析了滤波器的谐波抑制原理,给出了滤波器的仿真结果及分析。仿真结果表明:此滤波器设计新颖、结构简单、可靠性高,在各种工况条件下都能得到优化的滤波效果,很好地改善变频器的输出电压波形。

Depending on the characteristic of modern ship electric propulsion which is droven by frequency converter, a new type hybrid active power filter of sine wave is proposed. It is found that if a LC fundamental series-connected resonance branch is connected in the output side of a frequency converter, the series current converter will present low reactance to fundamental and the high impedance to the harmonics. At the same time,based on the instantaneous reactive power theory, the load line voltage can be measured in real time. Through an inverter and a series transformer, the voltage which has same value of harmonic voltage and is opposite to the phase of the harmonic voltage is injected into the load line voltage, thus the surplus harmonic voltage of the load line voltage can be counteracted. The construction and principle of the new type hybrid active power filter of sine wave are introduced in this paper and the theory of suppressing harmonics voltage is analyzed, and is simulated by MATLAB . The results of simulation show that the design of the filter is novel and the filter possesses the simple structure and the perfect reliability, and the optimum results of filter can be obtained in all kinds of work condition and the waveform of output voltage of frequency converter is improved clearly.