Case Studies on Dynamic Load Modeling

Independent system operators (ISOs) and other operating and planning entities have transient and dynamic stability requirements governing system performance regarding bus voltage dip and voltage recovery following the clearing of a disturbance. These requirements vary among transmission owners and operators. However, because of the observed trends of increasing motor and electronic loads in power grids, system study results have shown that transient and dynamic voltage performances can be significantly impacted by variations in load modeling, due to large variations in system voltages where short-term and long-term non-linear load characteristics may play an important role. Considering the stochastic nature of load composition and variation with voltage, it is a challenge to develop practical load models that can be used in power system planning and operation studies. This paper discusses the development and use of different load modeling approaches and its impacts in system studies.