*Article* **Current Source AC-Side Clamped Inverter for Leakage Current Reduction in Grid-Connected PV System**

#### **Xiangli Li, Na Wang, Guocheng San and Xiaoqiang Guo \***

Department of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China; lxl@ysu.edu.cn (X.L.); 18712728609@163.com (N.W.); hbsgc@163.com (G.S.)

**\*** Correspondence: gxq@ysu.edu.cn; Tel.: +86-13785070194

Received: 16 October 2019; Accepted: 29 October 2019; Published: 6 November 2019

**Abstract:** For the grid-connected photovoltaic inverters, the switching-frequency common-mode voltage brings the leakage current, which should be eliminated. So far, many kinds of single-phase inverters have been published for this purpose, but most of them are the conventional voltage-type ones, which have the disadvantages of poor reliability due to the DC-link electrolytic capacitor and the risk of short-through of the bridge switches. To solve this technical issue, a novel current source inverter with AC-side clamping is proposed to mitigate the switching-frequency common-mode voltage. Meanwhile, a novel modulation method is proposed for the new single-phase inverter to achieve low-frequency operation of the main switches, which reduces the switching losses. Finally, the proposed method is implemented on the TMS320F28335DSP + XC6SLX9FPGA digital hardware platform. Also, the performance comparisons are done with the traditional solution. The results prove the proposed solution.

**Keywords:** current source inverter; common-mode voltage; leakage current
