Improve the Stability and the Accuracy of Power Hardware-in-the-Loop Simulation by Selecting Appropriate Interface Algorithms

The closed-loop stability and the simulation accuracy are two paramount issues in power hardware-in-the-loop (HIL) simulation in regard to the operational safety and the experiment reliability. In this paper, the stability issue of the power HIL simulation is first introduced with a simple example. A stability analysis and accuracy estimation method based on the system's loop transfer function is later given. Five different interface algorithms are described, and their respective characteristics with respect to the system stability are compared. Through Matlab simulations and field experiments of two representative power HIL examples, it is revealed that certain interface algorithms exhibit higher stability and accuracy than the others under the given conditions. A recommendation for selecting appropriate interface algorith.ms is finally proposed at the end of this paper.

I. Introduction

Due to the fast development in computer technologies, particularly parallel computation techniques and various real-time simulation tools (e.g., Electromagnetic Transient Program-based software package), hardware-in-the-loop (HIL) simulation is applied more and more widely in the power electronics and power system fields. As an advanced design/test method, HIL simulations allow the prototype of a novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. Much literature has been published on utilizing HIL simulations for the tests of protection relays [1], [2], power converter controllers [3], and power quality regulators [4].