Abstract
Grid-tied photovoltaic inverters have several challenges concerning user safety. For instance, transformerless inverters may have high common-mode leakage current due to parasitic capacitance between photovoltaic modules and ground, making electric shocks detection difficult. Inverters must be submitted to several tests to certify its compliance with safety standards. This manuscript addresses the insulation resistance test and residual current tests described in safety standard IEC 62109-2. A variable RC load that can be used for both tests is designed and its functionality is demonstrated by simulation results.