MODELLING METHOD AND SYSTEM FOR DIODE CLAMPED CASCADED MULTI-LEVEL CONVERTER

摘要

A modelling method and system for a diode clamped cascaded multi-level converter. All corresponding diodes of each bridge arm are equivalent to an auxiliary diode; all corresponding capacitors of each bridge arm are equivalent to a controlled voltage source; and power modules of each bridge arm are connected in series to be equivalent to an equivalent module, the equivalent module comprising a loss resistor and a composite equivalent model connected to the loss resistor. Since a plurality of components, at the same positions, in each power module of each bridge arm of the diode clamped cascaded multi-level converter are equivalent to a component, the node voltage equation order can be reduced, the simulation efficiency is improved, and the simulation efficiency cannot be reduced with the increase in the number of power modules. By means of modelling according to the modelling method and system, the demands for flexible direct current power transmission engineering parameter design, control strategy verification and the like of a long-distance, high-capacity and overhead line occasion can be satisfied.