Geometric manifold control of power electronics in Dc microgrids

The presence of switched power converters in modern day power systems and microgrids can make the control challenging and costly. The switch states of the converters need to be determined properly for the system to operate normally in both steady state and transient conditions. This work proposes the derivation of an optimal geometric manifold in the energy-power domain for various transient events. The proposed states are the energies stored in various energy storage devices like a dc-dc converter and the power flowing into these elements. The optimal trajectories are assembled to form a reference geometric manifold. These trajectories are saved into a digital memory based controller which is used as a hysteretic sliding mode surface control strategy. This strategy effectively controls the system under a normal operating condition as well as under transient conditions such as step changes a load. It is anticipated that calculating a large enough set of dissimilar transient scenarios to populate the switching surface will also span many scenarios not specifically implemented.