As the world strives towards finding alternative sources of power generation, photovoltaic generation has become an increasingly prevalent alternative energy source on power systems world-wide. This paper studies the effects that incorporating photovoltaic generation has on the existing power systems and their power system protection schemes. Along with the addition of this emerging alternative energy source comes the volatility of PV power generation as cloud-cover produces erratic variations in solar irradiance and PV power production. Such variations in PV power may lead to unfavorable operating conditions and power system failures. The issues addressed in this paper include a study of inverter harmonic levels for variations in DC voltage and power, and a study of power system protection failures caused by cloud-induced PV power variations. Such issues are addressed so as to provide a better understanding of the effects that cloud-induced PV power generation variability has on power systems and its protection schemes.