A steady-state equivalent model of solid state transformers for voltage regulation studies

Solid State Transformers (SSTs) are power electronic-based transformers that will be a vital component of the future smart grid with high amount of renewable energy integration and the need for improved controllability. Among its various unique features, the reactive power compensating capabilities of SSTs can be exploited in future smart distribution systems for voltage regulation under high renewable energy penetrations. SSTs are power electronic devices that show fast and non-linear dynamics which means the simulation models are often complicated and need small time steps for accurate solutions. This prevents real-time and long-term simulation of large distribution systems as the simulations become computationally prohibitive. This paper designs a simplified equivalent model of an SST using simple current and voltage sources along with simple modeling equations. These simplified models can be used to perform long-term voltage regulation studies of distribution systems where traditional transformers are replaced with SSTs.