Direct Current Control System

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Background and Basic Concept of the Technology HVDC control systems are usually designed by methods and systems which utilize, for example, a state-variable approach to define the linear and nonlinear differential equations of a classic HVDC control system. This approach typically requires accurate knowledge of Alternative Current (AC) systems and corresponding Direct Current (DC) systems and undesirably involves complicated mathematics as well as computationally intensive calculations in order to achieve an end result. The invention comprises the steps of determining at least a current control plant transfer function for a rectifier and/or inverter of the classic HVDC control system by using a time domain current equation; determining at least a voltage control plant transfer function for at least a rectifier of the classic HVDC control system by using a time domain voltage equation; using the determined current control plant transfer function for the rectifier and/or inverter, and/or the determined voltage control plant transfer function for at least the rectifier to facilitate design of the HVDC control system. Applications & Market Opportunities In practice, it is extremely difficult, if not impossible, to obtain accurate knowledge of the AC systems connected to classic HVDC control systems. In this regard, limited time constraints imposed on HVDC control practitioners, the AC system uncertainties, and the complicated mathematics have prevented the widespread practical use of the state-variable approach to derive the plant transfer functions of classic HVDC control systems. Trial and error methods employed to design HVDC control systems require expert knowledge of which there is a shortage of. Also, these trial and error techniques are undesirably labour intensive and not necessarily robust. In this regard, the present invention seeks at least to address the abovementioned problems and to provide a faster, more convenient way in HVDC control systems can be designed. Stage of Development Development. Intellectual Property Status Patents filed in South Africa (2010/0830), USA (13/577,436), China (2011800155859) and Europe (11739482.5). Collaboration Sought Industry Partner/Funders.