Modeling synchronous voltage source converters in transmission system planning studies

A voltage source converter (VSC) can be beneficial to power utilities in many ways. To evaluate the VSC performance in potential applications, the device has to be represented appropriately in planning studies. This paper addresses VSC modeling for EMTP, power flow and transient stability studies. First, the VSC operating principles are overviewed and the device model for EMTP studies is presented. The ratings of VSC components are discussed, and the device operating characteristics are derived based on these ratings. A power flow model is presented and various control modes are proposed. A detailed stability model is developed, and its step-by-step initialization procedure is described. A simplified stability model is also derived under stated assumptions. Finally, validation studies are performed to demonstrate performance of developed stability models and to compare it with EMTP simulations