A Stochastic Power Flow Study to Investigate the Effects of Renewable Energy Integration

Renewable energy sources (RESs), such as wind and solar power become an integral part of the energy mix in the vast majority of countries around the world. Due to the variable and uncertain nature of RESs, the power flow of power systems with renewable penetration is no longer deterministic but probabilistic. Power flow study is vital to system daily operations as well as stability and economics. This paper investigates the effects of renewable energy integration on power system from a stochastic power flow point of view. Electrical load is assumed to follow a normal distribution. Wind and solar power scenarios are generated from the Weibull and lognormal probability distribution functions. The modified IEEE 39 bus testing system with RES penetration is modeled in a professional power system simulation software named DIgSILENT PowerFactory and it is further used for testing. Optimal power flow is running in each scenario of the stochastic process and the system without RES penetration is regarded as the base case. The effects of RESs on power system are analyzed comparatively in terms of generation cost, power losses, bus voltage deviations and line loading.