重复控制三相电压型准Z源光伏并网逆变系统

发布时间：2018-08-04 08:58

【摘要】：为提高准Z源逆变器的升压能力和并网电流质量,提出了一种采用重复控制的强升压能力的单级三相电压型准Z源光伏并网逆变系统,并对这种逆变系统的电路拓扑、改进的空间矢量脉宽调制(space vector pulse width modulation,SVPWM)控制策略、离散控制系统的稳定性和调制器设计进行了分析。该系统电路拓扑是由大升压比准Z源阻抗网络、三相逆变桥和三相LCL滤波器构成;改进的SVPWM控制策略包括光伏阵列最大功率点跟踪控制和储能电容电压外环、并网电流内环控制,其中并网电流内环采用逆变器侧电流反馈控制策略,且融入了电网电压比例前馈、重复控制和PI串联的嵌入式复合控制来提高并网电流质量。实验结果证实了所提逆变系统电路拓扑、控制策略和系统设计的有效性。
[Abstract]:In order to improve the boost capacity and grid-connected current quality of quasi-Z-source inverter, a single-stage three-phase voltage quasi-Z-source photovoltaic grid-connected inverter system with strong boost capacity of repetitive control is proposed. The circuit topology of this inverter system is also discussed. The improved space vector pulse width modulation (SVPWM) control strategy, the stability of discrete control system and the design of modulator are analyzed. The circuit topology of the system is composed of a large boost ratio quasi-Z source impedance network, a three-phase inverter bridge and a three-phase LCL filter. The improved SVPWM control strategy includes the maximum power point tracking control of photovoltaic array and the external loop of energy storage capacitor voltage. Grid-connected current inner loop control, in which grid-connected current inner loop adopts inverter side current feedback control strategy, and integrates power grid voltage proportional feedforward, repetitive control and Pi series embedded composite control to improve grid-connected current quality. The experimental results show the effectiveness of the proposed inverter circuit topology, control strategy and system design.
【作者单位】：福建省新能源发电与电能变换重点实验室(福州大学);
【基金】：国家自然科学基金重点项目(51537001)~~
【分类号】：TM464;TM615

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