大容量光伏逆变器LCL滤波器参数优化设计

对于大容量联网光伏逆变器系统，其配置的LCL滤波器总电感量大小直接关系到系统的尺寸和成本。为此，提出了一种根据滤波性能要求，使总电感量最小的LCL参数优化设计方法。该方法以电容支路消耗无功大小，注入电网谐波电流与对应频次谐波电压幅度比作为滤波器性能考核参数。通过引入电容支路与网侧电感支路对高频谐波电流的分流比参数，建立了总电感量与主要设计参数之间的函数关系，给出了总电感量最小的参数条件及其求解方法。设计算例及仿真结果验证了所提出设计方法的实用性与有效性。

Parameter optimization design for LCL filter of large capacity PV inverter

For the large-scale grid-connected PV inverter system, the total inductance of the LCL filter is directly related to the size and cost of the system. Therefore, a LCL parameters optimization design method is proposed to make its total inductance minimum meeting the filtering performance requirements. The consumption of reactive power of the capacitance branch and the amplitude ratio of the injected harmonic current to the corresponding frequency harmonic voltage are set as filter performance appraisal parameters in this method. By introducing the split ratio parameter of the high frequency harmonic current of capacitance branch and the grid side inductance branch to the high frequency harmonic current, the functional relationship between the total inductance and the main design parameters is established, and the parameter condition of minimum total inductance and its solving method are given. The design example and simulation verify the practicability and availability of the proposed design method.