Control of Three-Phase Bidirectional Current-Source Converter to Inject Balanced Three-Phase Currents Under Unbalanced Grid Voltage Condition
Control of Three-Phase Bidirectional Current-Source Converter to Inject Balanced Three-Phase Currents Under Unbalanced Grid Voltage Condition
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DOI：
10.1109/tpel.2015.2503352
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发表时间：
2016-09
影响因子：
6.7
通讯作者：
V. Vekhande;V. K. Kanakesh;B. G. Fernandes
中科院分区：
文献类型：
--
作者：
V. Vekhande;V. K. Kanakesh;B. G. Fernandes
文献报道了一种将直流微电网与交流电网连接起来的单级双向电流源转换器 (CSC) 拓扑。在该拓扑中，在平衡电网电压条件下，直流母线电感电流可以在从零到额定值的宽范围内调节，而交流侧电流具有较低的谐波失真。然而，不平衡的电网电压会导致转换器直流侧的电流和功率产生二次谐波脉动。此外，由于负序分量的存在，交流侧电流也会不平衡。如果一相电流超过其额定值，这将导致转换器意外跳闸。文献中报道了在不平衡电网电压条件下电压源换流器运行的各种控制回路结构。然而，对 CSC 使用类似的控制环路结构可能会导致运行不稳定。因此，本文提出了一种在电网电压不平衡条件下向交流电网注入平衡三相电流的控制方案。使用转换器的小信号模型研究了所提出的控制方案的稳定性。使用 MATLAB/Simulink 研究了所提出的控制方案的性能并进行了实验验证。
A single-stage, bidirectional, current-source converter (CSC) topology to interface a dc microgrid with an ac grid is reported in the literature. In this topology, under a balanced grid voltage condition, the dc-link inductor current can be regulated over a wide range-from zero to rated value-while the ac-side current has low harmonic distortion. However, unbalanced grid voltages result in second-harmonic pulsation in the current and power on the dc side of the converter. In addition, the ac-side currents will be unbalanced due to the presence of a negative-sequence component. This would result in undesired tripping of the converter if one of the phase currents exceeded its rated value. Various control loop structures for the operation of voltage-source converter under unbalanced grid voltage conditions are reported in the literature. However, use of similar control loop structures for CSC may lead to unstable operation. Therefore, a control scheme to inject balanced three-phase currents into the ac grid under an unbalanced grid voltage condition is proposed in this paper. The stability of the proposed control scheme is studied using a small-signal model of the converter. Performance of the proposed control scheme is studied using MATLAB/Simulink and is experimentally validated.