Multi-Rate Mixed-Solver for Real-Time Nonlinear Electromagnetic Transient Emulation of AC/DC Networks on FPGA-MPSoC Architecture

Tong Duan,Zhuoxuan Shen,Venkata Dinavahi

doi:10.1109/jpets.2019.2933250

Tong Duan, Zhuoxuan Shen + Show 1 more

Open Access

https://doi.org/10.1109/jpets.2019.2933250

Copy DOI

Abstract

Nonlinear phenomena widely exist in AC/DC power systems, which should be accounted for accurately in real-time electromagnetic transient (EMT) simulation for obtaining precise results for hardware-in-the-loop applications. However, iterative solutions such as the Newton-Raphason method that can precisely obtain the results for highly nonlinear elements, are time consuming and computationally onerous. To fully utilize the time space and optimize hardware computation resources without loss of accuracy, this work proposes a novel multi-rate mixed-solver for AC/DC systems, wherein both iterative and non-iterative solvers with different time-steps are applied to the decomposed subsystems, and the linear solvers are reused within each time-step. The proposed solver and the complete real-time emulation system are implemented on FPGA-MPSoC platform. The real-time results are captured by the oscilloscope and verified with PSCAD/EMTDC and SaberRD for system-level and device-level performance evaluation.

Highlights

Nolinearities exist in a wide range of elements in power systems and power electronics circuits, such as the nonlinear v − i characteristic of protective surge arresters, magnetic saturation and hysteresis of transformers, and nonlinear switching phenomena of power converters and power electronics devices
The example test case described in Section IV is emulated on the three FPGA/MPSoC boards and the results are compared with PSCAD/EMTDC and SaberRD to show the effectiveness of the proposed multi-rate mixed-solver
The logic resource cost can be reduced by about 11.3%, and the computing resource cost can be reduced by about 13.1%

Summary

INTRODUCTION

Nolinearities exist in a wide range of elements in power systems and power electronics circuits, such as the nonlinear v − i characteristic of protective surge arresters, magnetic saturation and hysteresis of transformers, and nonlinear switching phenomena of power converters and power electronics devices. This work proposes a novel multi-rate mixed-solver (MRMS) for the real-time EMT simulation of large-scale AC/DC grids, in which both the iterative solver for nonlinear elements and the conventional non-iterative solver are applied for different subsystems, and the time-step can be different among subsystems to achieve optimum performance for the overall accuracy and computation hardware resource consumption. Based on the above observations, the multi-rate mixed-solver is proposed: to ensure high accuracy, both the iterative solver for nonlinear elements and the conventional non-iterative linear solver are applied for different subsystems; and to reduce computation resource consumption, the multiple time-step scheme is used and carefully designed for different subsystems. After each time-step, results of the NSS and LSS with small time-step and the LSS with large time-step are outputted for display respectively and history items are exchanged between adjacent subsystems

SUGGESTED PROCEDURE FOR TIME-STEP SELECTION

RESULTS AND VERIFICATION

REAL-TIME EMULATION RESULTS

CONCLUSION