Efficient and Accurate Multirate Simulation of HVDC Converters in a Partitioned Network Environment

Multirate simulation of electric networks exhibiting a wide variety of time constants decreases the simulation runtimes by exploiting the property of circuit latency. The fundamental idea is to use different integration steps for distinct elements and/or parts of the network according to requirements of accuracy for each element. HVDC converters are ideally suited for latency exploitation since the differences in step size requirements are well defined. This paper presents the recent developments for an efficient and accurate circuit latency exploitation as well as the results obtained when a twelve-pulse HVDC converter is simulated using this technique. Latency is exploited using direct integration methods instead of the traditional iterative methods, making the approach suitable for real-time simulation. Comparisons are made with the traditional single step solution in order to emphasize the accuracy and efficiency of the proposed method.