Cascade Control Vs. Full State Feedback for a Grid Converter

The performance of two control structures for a Grid-Connected Converter is compared. Control quality and stability margins are considered.

Two concepts of controlling the grid-connected converter go toe to toe. In the model you will find the comparison of the very popular among practitioners, cascade control structure with the full state feedback structure, being a top choice for power electronics researchers.

In contrast to cascade control, the full state feedback uses multiple parallel feedbacks at one stage. In this model, we check whether it gives any advantage.

The cascade control structure is tuned using a well-recognized theory, Cessler’s Criterions. To ensure a fair comparison, the parallel structure is tuned to get the same stability margin.

What if the theory fails?

… It does not, but you can convince yourself. In lines 124-128, you can put your controller gains and check if it is possible to get a bigger stability margin (larger disk) with better performance than the performance of parallel structure.