Large-Signal Stabilization of Power Converters Cascaded Input Filter Using Adaptive Energy Shaping Control

Shengzhao Pang,Fei Gao,Babak Nahid-Mobarakeh,Serge Pierfederici,Yigeng Huangfu,Guangzhao Luo,Saeid Aghaei Hashjin

doi:10.1109/tte.2020.3021954

Abstract

Series connection of input filters with static converters might lead to instability. However, the input filter has rarely taken into account in the stable design of power converters. Indeed, an input LC filter cascaded with a converter can become unstable even if the converter is regulated by a tight controller ensuring its stability alone. This fact is due to the interactions between the filter and the converter. To tackle the instability potential, an adaptive energy shaping control (AESC), which is based on the interconnection and damping assignment passivity-based control (IDA-PBC), is addressed in this article to regulate the cascaded system and achieve the following attractive features: 1) the input filter's dynamics are considered in the control law, so the interactions between the filter and the converter are taken into account during the controller design and 2) the influence between several subsystems, put in cascade, is considered by the proposed method, and the new large-signal stability proof is given accordingly. Simulation and experimental results from a 3.5-kW, 270-200-V buck converter cascaded with an input filter under different load conditions, i.e., constant impedance load (CIL), constant current load (CCL), and constant power load (CPL), are presented to demonstrate the proposed approach.

Highlights

IntroductionDC distribution power system in the form of dc microgrid has received increasing attention, especially in electrified transportation applications such as More Electric Aircraft (MEA), Electric Vehicles (EVs), ships, and submarines [1], [2], [3]
DC distribution power system in the form of dc microgrid has received increasing attention, especially in electrified transportation applications such as More Electric Aircraft (MEA), Electric Vehicles (EVs), ships, and submarines [1], [2], [3].In this application, instability is still a key issue in the design of dc microgrids
This paper proposes an Adaptive Energy Shaping Control (AESC) which is based on the IDA-Passivity-Based Control (PBC) methodology

Summary

Introduction

DC distribution power system in the form of dc microgrid has received increasing attention, especially in electrified transportation applications such as More Electric Aircraft (MEA), Electric Vehicles (EVs), ships, and submarines [1], [2], [3] In this application, instability is still a key issue in the design of dc microgrids. These systems, consisting of multiple cascaded or parallel converters, can suffer from instability, even when individual converters are stable alone [ 4 ], [ 5 ] This instability can be induced by the interactions between the individually designed converters or the influences from the poorly damped input LC filter and tightly regulated loads, e.g., constant power loads [6], [7]. Such filters are usually poorly damped for size/weight optimization or loss reduction consideration [12]

Methods

Results

Conclusion