Basic Method of Building UDC Model for RTDS Simulation

Although real-time digital simulator (RTDS) has included most common components in its component model library, some models have to be built by the user with so called Used-Define Component (UDC) technique to meet particular simulation requirements. This paper first expatiate on the numerical discrete principle on which the consecutive differential equations (math model) of basic component could be transformed to discrete difference equations (numerical calculation model) so that the model's characteristic and behaviors can be represented via program codes. Next the paper introduces the configuration of an UDC component model that the model is defined by two files respectively with postfix dft and udc. In succession, the paper describes detailed process of building an UDC component model with a double damped filter as example. Finally, a validation test for UDC model accuracy is taken by a RTDS simulation case and the test gives a high degree of accredited result.