Dynamic Simulation of HVDC Power Transmission Systems on Digital Computers - Generalized Mesh Analysis Approach

This paper introduces and develops a new generalized approach to the dynamic simulation of an HVDC power transmission system. The approach involved is a generalized method of mesh analysis applied to the HVDC network. The simulation of HVDC convertors is characterized by the fact that the network to be solved changes with each discontinuity, such as valve firing and end of commutation. To facilitate such an analysis, topology is used and a technique is developed for the automatic selection of the appropriate network by recognizing the state of conducting and nonconducting valves. The method is inherently suitable for following the natural process of convertor operation which may culminate in various faults. To illustrate this method a simple HVDC system consisting of one convertor at each end is considered. Essential features of the program are shown by deriving waveforms of normal operation, commutation failure, four-valve conduction, bypass valve operation, and backfire.