A Study of Interpolation Compensation Based Large Step Simulation of PWM Converters

Abstract

Real-time online simulation based on a real-time workshop (RTW) plays a vital role in the study and application of power electronics. However, restricted by the performance of equipment and hardware, the simulators so far available in the market mainly support simulation steps over 50 μs, while large step simulation may result in the action delay of pulse-width modulating (PWM), numerical oscillation and high-level non-characteristic harmonic distortion. In view of these problems, this paper puts forward a modeling method based on integral prediction and interpolation compensation. First of all, prediction is performed one step in advance by the implicit trapezoidal method to find out the accurate time when the triangle carrier wave intersects with the modulation wave. At the same time, a mathematic model is built for the insulated gate bipolar transistor (IGBT) to output equivalent voltage waveform according to the principle of area equivalent. Next, in MATLAB/Simulink, offline simulation is performed with the three-phase AC-DC-AC converter as the subject. By comparing the control accuracy, the content of harmonic wave and the simulation time, the simulation effects of the 50 μs fixed-step interpolation prediction model are the same as that for a 5 μs fixed-step standard model. Finally, the effectiveness and high efficiency of this algorithm are verified on a real-time simulator, marking the application of offline models on real-time simulators.

Parallel computing of spatial big data and derivation of asymptotic behavior of statistical partition equation

“…Therefore, a computing mode with high scalability, high computing efficiency, and support for spatial big data analysis is designed. Single-step or numerical integration theory (such as implicit trapezoidal integration) can be used to perform simultaneous computations at time points [3], but the above methods do not have time-parallel features in the study of time modules in parallel computing [4]. However, multilevel implicit Runge Kutta theory is often used in time-parallel computing because of its good time-parallel features [5].…”