With the integration of the high penetration PV power generation into the electric power system, the feeder voltage is facing various fluctuation problems. In severe condition, the system operation may be impacted due to the voltages violate the limitations that specified in grid codes. As the result, the relevant regulations and technical standards have been emerged; meanwhile, CNS 15382 standard in Taiwan is mainly used to describe the characteristics of utility interface in PV systems. This paper focuses on the investigation of the functionality on PV Inverter autonomous voltage regulation according to CNS 15382 standard. Both simulation analysis and on-site testing are implemented to present the power factor control and active power control mechanisms, required in CNS 15382, for voltage regulations.