Leakage Current Reduction with 240CPWM in Silicon Carbide based Transformerless Grid-connected PV Converter
Leakage Current Reduction with 240CPWM in Silicon Carbide based Transformerless Grid-connected PV Converter
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DOI：
10.1109/ecce50734.2022.9947898
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
Hafsa Qamar;Haleema Qamar;Nikhil Korada;Madhura Sondharangalla;R. Ayyanar
中科院分区：
文献类型：
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作者：
Hafsa Qamar;Haleema Qamar;Nikhil Korada;Madhura Sondharangalla;R. Ayyanar
由于缺乏电流隔离，高泄漏电流是无变压器并网(TLGC)光伏变流器的主要可靠性问题之一。TLGC光伏系统中光伏组件的大泄漏电容使得泄漏通道的谐振频率很低。如果逆变器的开关频率接近传统逆变器的谐振频率，就会产生很大的泄漏电流。开关频率可以保持在高于泄漏路径的谐振频率，以实现较低的泄漏电流。一种相对较新的被称为钳位PWM(240CPWM)的PWM方法鼓励使用更高的开关频率，因为它的开关损耗最低。这项工作在开关频率为100 kHz的碳化硅逆变器中部署了240CPWM，与10 kHz的硅基逆变器相比，在不影响逆变器效率的情况下，泄漏电流节省了70%，交流滤波电感体积减少了4.7倍。
High leakage current is one of the major reliability concerns in transformerless grid-connected (TLGC) PV converters due to lack of galvanic isolation. Large leakage capacitance of PV modules in TLGC PV systems makes the resonant frequency of the leakage path very low. It forces high leakage current if switching frequency of inverter is close to the resonant frequency as in traditional inverters. Switching frequency can be kept higher than the resonant frequency of the leakage path to achieve lower leakage currents. A relatively new PWM method called $240^{\circ}$ clamped PWM (240CPWM) encourages the use of higher switching frequency because of its lowest switching loss. This work deploys 240CPWM in silicon carbide based inverter at switching frequency of 100 kHz that gives 70% saving in leakage current and 4.7 times reduction in AC filter inductor volume as compared to silicon based inverter switching at 10 kHz without compromising the inverter efficiency.