Zero Dynamic DC-Link Voltage Control for Current Source Converter Under Grid Disturbances

DC-link dynamic is one of the most important issues for current source converters (CSC). In practice, the dc-link voltage suffers from the slow dynamic due to grid disturbances, which will affect the quality of output waveform and damage the converter. Many solutions have been presented to cope with it, but none of them achieve the zero dynamic dc-link voltage control. In order to fill the technical gap, a novel solution is proposed in this article. First, the impact of grid disturbances on the CSC is discussed with instantaneous power theory and small-signal model analysis. Second, a new solution is presented to eliminate the adverse impacts of grid disturbances, so as to achieve the zero dynamic dc-link control concept. Meanwhile, the power quality of grid current is improved. Finally, the experiments for the proposed solution under grid disturbances are carried out with TMS320F28335 DSP + XC3400 FPGA digital control hardware platform. The experimental results verify the effectiveness of the proposed solution.