In a photovoltaic array (PVA) tied grid system, PVA and the grid are connected at AC bus (ACB) to feed the power to the grid and the load connected locally at the ACB. The photovoltaic energy conversion system (PVECS) requires an improved dynamic controller to control the grid voltage harmonics under variable solar power and nonlinear unbalanced load conditions. The conventional filtering controllers are unable to remove the sub-harmonics and DC-offset in the input signal. Moreover, their attenuation for the dominant lower order harmonics is unsatisfactory for unbalanced loading conditions and highly nonlinear loads. A MMLSTOGI (mixed multi-level second and third order generalized integrator) based control is used in this work. It effectively mitigates the dominant lower-order harmonics and the DC-offset of load currents and extracts their in-phase and quadrature-phase fundamental components (FCs). The PVA is connected at ACB through interfacing voltage source converter (VSC). The DC-link voltage is ascertained by generating its reference value using an incremental conductance (InC) based maximum power point tracking. The PVA power is feed-forwarded in the control to enhance the dynamics of the system. The control is validated on a developed model in MATLAB SIMULINK background, and using a developed prototype.

中文翻译：

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基于MMLSTOGI的控制可抑制光伏并网电网中的电流谐波

在光伏阵列（PVA）并网系统中，PVA和电网在AC总线（ACB）处连接，以向电网馈电，而负载则在ACB处本地连接。光伏能量转换系统（PVECS）需要改进的动态控制器，以在可变太阳能和非线性不平衡负载条件下控制电网电压谐波。传统的滤波控制器无法消除输入信号中的次谐波和直流偏移。此外，对于不平衡的负载条件和高度非线性的负载，它们对于主要的低阶谐波的衰减是不令人满意的。在这项工作中使用基于MMLSTOGI（混合的多级第二和第三级广义积分器）的控件。它有效地减轻了主要的低阶谐波和负载电流的直流偏移，并提取了它们的同相和正交相基本分量（FC）。PVA通过接口电压源转换器（VSC）连接到ACB。直流母线电压通过使用基于增量电导（InC）的最大功率点跟踪生成参考值来确定。PVA电源在控制系统中进行前馈，以增强系统的动力。该控件已在MATLAB SIMULINK后台的开发模型上验证，并使用了开发的原型。直流母线电压通过使用基于增量电导（InC）的最大功率点跟踪生成参考值来确定。PVA电源在控制系统中进行前馈，以增强系统的动力。该控件已在MATLAB SIMULINK后台的开发模型上验证，并使用了开发的原型。直流母线电压通过使用基于增量电导（InC）的最大功率点跟踪生成参考值来确定。PVA电源在控制系统中进行前馈，以增强系统的动力。该控件已在MATLAB SIMULINK后台的开发模型上验证，并使用了开发的原型。