Cascaded MVDC Integration Interface for Multiple DERs With Enhanced Wide-Range Operation Capability: Concepts and Small-Signal Analysis

摘要

In this letter, the novel concept of cascaded dc integration interface for multiple distributed energy resources (DERs) has been proposed for the scenario of MVdc distribution grid. The power equalizers are introduced to achieve the wide-range operation of DERs. A closed-loop small-signal modeling of the cascaded integration interface is performed with graphical method, and the corresponding control strategy for power equalizers are given with a detailed investigation on system stability. The design principles of control parameters are discussed so as to have achieved the expected dynamic performance. Both simulation and down-scaled experiment are performed to verify all theoretical results.