SiC devices can upgrade the inverter performance to a new level by its potentially more than ten times higher switching speed compared to its Si counterpart. However, the high switching frequency and dv/dt, di/dt worsen the electromagnetic interference. Reduction of the common mode (CM) noise of the non-isolated photovoltaic (PV) inverters is addressed by many researchers through adding filters or balancing the circuit. However, most methods rely on the certainty of the parasitics in the system in advance. It is usually not practical for a PV inverter because the parasitic capacitance of PV panels that are to be installed in plants varies from case to case and further can be seriously affected by the damp environment. This article proposes a practical way to reduce the CM noise of the three-level active neutral point clamped (ANPC) inverters with uncertain parasitic capacitance of PV panels. First, the CM model of ANPC inverters with all parasitic capacitances is established. Next, most existing hardware-based reduction methods of the CM noise are summarized based on a unified mathematical model and further compared with each other. After the comparison, a practical method is proposed to reduce the CM noise of the ANPC inverter with uncertain parasitic capacitances, which just adds little volume and cost to the whole system. Finally, the simulation and experiments are conducted to validate the proposed method.

中文翻译：

---

光伏板寄生电容不确定的三电平有源中性点钳位逆变器的共模降噪

与 Si 器件相比，SiC 器件的开关速度可能高出十倍以上，因此可以将逆变器性能提升到一个新的水平。然而，高开关频率和 dv/dt、di/dt 会加剧电磁干扰。许多研究人员通过添加滤波器或平衡电路来降低非隔离光伏 (PV) 逆变器的共模 (CM) 噪声。然而，大多数方法预先依赖于系统中寄生参数的确定性。对于光伏逆变器来说，这通常是不切实际的，因为要安装在工厂中的光伏电池板的寄生电容因情况而异，并且还会受到潮湿环境的严重影响。本文提出了一种实用的方法来降低具有不确定光伏电池板寄生电容的三电平有源中性点钳位 (ANPC) 逆变器的共模噪声。首先，建立了具有所有寄生电容的ANPC逆变器的CM模型。接下来，基于统一的数学模型总结了大多数现有的基于硬件的CM噪声降低方法，并进一步相互比较。经过比较，提出了一种降低寄生电容不确定的ANPC逆变器共模噪声的实用方法，该方法对整个系统的体积和成本几乎没有增加。最后，通过仿真和实验验证了所提出的方法。大多数现有的基于硬件的CM噪声降低方法基于统一的数学模型进行总结，并进一步相互比较。经过比较，提出了一种降低寄生电容不确定的ANPC逆变器共模噪声的实用方法，该方法对整个系统的体积和成本几乎没有增加。最后，通过仿真和实验验证了所提出的方法。大多数现有的基于硬件的CM噪声降低方法基于统一的数学模型进行总结，并进一步相互比较。经过比较，提出了一种降低寄生电容不确定的ANPC逆变器共模噪声的实用方法，该方法对整个系统的体积和成本几乎没有增加。最后，通过仿真和实验验证了所提出的方法。