**Investigations on EMI Mitigation Techniques: Intent to Reduce Grid-Tied PV Inverter Common Mode Current and Voltage**

### **Umashankar Subramaniam 1,\*, Sagar Mahajan Bhaskar 1, Dhafer J.Almakhles 1, Sanjeevikumar Padmanaban 2 and Zbigniew Leonowicz 3**


Received: 1 August 2019; Accepted: 29 August 2019; Published: 3 September 2019

**Abstract:** Power inverters produce common mode voltage (CMV) and common mode current (CMC) which cause high-frequency electromagnetic interference (EMI) noise, leakage currents in electrical drives application and grid-connected systems, which consequently drops the e fficiency of the system considerably. This CMV can be mitigated by designing suitable EMI filters and/or investigating the effects of di fferent modulation strategies. In this paper, the e ffect of various modulation techniques over CMV and CMC are investigated for two-level and three-level inverters. It is observed that the modified third harmonic injection method reduced the CMV and CMC in the system by 60%. This modified pulse width modulation (PWM) technique is employed along with EMI chokes which results in reduced distortion of the system.

**Keywords:** common mode current; common mode voltage; modulation techniques; electromagnetic interference; mitigation; grid connected inverters
