两象限变频器直流电容纹波电流分析与抑制研究

Analysis and inhibition studies of the ripple current on the DC capacitor of two quadrant converter

两象限变频器直流环节设计的好坏决定着变频器整机性能优劣以及可靠性高低,而直流环节的设计又是以直流电容的选型设计为主。为了稳定中间环节直流电压,使其波动在所要求的设计范围之内,在进行直流电容选型时,设计者通常会选用容量大的电解电容。但电解电容额定纹波电流小,为保证电容的使用寿命,采取一定措施抑制电容纹波电流显得十分必要。本文通过对两象限变频器直流电容纹波电流进行分析,提出了添加直流电感抑制电容纹波电流的方法,并分别给出了计算电容纹波电流的数学解析式,最后通过MATLAB仿真验证了理论分析的正确性。

The DC-link design of two quadrant inverter determines the inverter performance and reliability, and the Dc-link design is mainly for de capacitance type selection. When making DC capacity selection, designers often use large capacity electrolytic capacitor to stabilize the voltage of DC-link, keep the voltage fluctuation in the design scope. Electrolytic capacitor rated ripple current is small so we must take measures to restrain ripple current for keeping the capacitance have longer service life. In this paper, the de capacitance ripple current of two quadrant inverter is analyzed, the method of adding the de inductance to inhibit capacitor ripple current is put forward, The analytic expression of capacitance ripple current is given. Finally the correctness of the theoretical analysis is verified by MATLAB simulation.