Stability Effect of Load Converter on Source Converter in a Cascaded Buck Converter
Stability Effect of Load Converter on Source Converter in a Cascaded Buck Converter
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DOI：
10.1109/tpel.2022.3199234
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发表时间：
2023-01
影响因子：
6.7
通讯作者：
Xi Zhang;Tianshi Wang;H. Bao;Yihua Hu;B. Bao
中科院分区：
文献类型：
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作者：
Xi Zhang;Tianshi Wang;H. Bao;Yihua Hu;B. Bao
在级联功率变换器中，负载变换器的输入电流纹波被前馈到源变换器的输出电容，从而重塑源变换器的输出电容电流和输出电压纹波。为了研究负载变换器前馈电流纹波对源变换器稳定性的影响，以由两个峰值纹波控制降压变换器组成的级联功率变换器为例。首先，对源变换器在级联工作和独立工作时所选电路参数的稳定性影响进行了论证和比较。其次，通过描述由前馈纹波引起的三种开关状态序列，建立了级联功率变换器的离散时间映射模型。基于映射模型，阐述了源变换器随电路参数变化的不稳定机理，并在电路参数平面上得到了稳定边界。结果表明，前馈纹波源变换器的电路参数对稳定性的影响与单机运行时有本质区别。仿真结果和实验结果验证了理论分析的正确性。
In a cascaded power converter, the input current ripple of load converter is fed forward to the output capacitor of source converter and results in reshaping the output capacitor current and output voltage ripples of source converter. To investigate the stability effect of feedforward current ripple of load converter on source converter, a cascaded power converter comprising two peak-voltage-ripple controlled buck converters is taken as an example. First, the stability effects of chosen circuit parameters of the source converter in cascaded operation and standalone operation are demonstrated and compared. Second, by describing three switching state sequences induced by the feedforward current ripple, a discrete-time map model is established for the cascaded power converter. Based on the map model, the instability mechanism of source converter with the variations of the circuit parameters is thereby expounded, and the stability boundaries are obtained in the circuit parameter planes. The results show that the stability effects of the circuit parameters of source converter with feedforward current ripple are essentially different from those in the standalone operation. The theoretical analyses are verified by the simulation results and experimental results.