Inverter-Based Renewable (IBR) generators are becoming a major energy source for the modern grid, replacing coal generators. These generators use power electronics to interface with the grid, which has fundamentally different characteristics from traditional electro-mechanical synchronous generators. This shift presents new challenges in planning and operating the electric grid. The behavior of IBRs is primarily determined by their control systems, making it critical to understand their behavior for effective grid planning and operation. Traditional analysis methods are insufficient for studying IBRs, particularly under weak grid conditions, necessitating more advanced techniques. Electromagnetic transient (EMT) simulation tools like PSCAD are widely used to model IBRs and assess their impact on the grid. This presentation provides an overview of the challenges facing the modern grid and demonstrates the use of EMT simulation tools to study and address these challenges. The presentation also covers the fundamentals of electromagnetic transients.