An AC–DC Hybrid Multi-Port Energy Router With Coordinated Control and Energy Management Strategies

Bin Liu,Chengxiong Mao,Chunxiao Zhou,Weihan Wu,Dan Wang,Guanglin Sha,Qing Duan

doi:10.1109/access.2019.2933469

Bin Liu, Chengxiong Mao + Show 5 more

Open Access

https://doi.org/10.1109/access.2019.2933469

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Abstract

Energy router is an intelligent power electronic device that can realize the active management of power flow and provide convenient access to distributed energy resource. This paper presents the structure of an AC-DC hybrid multi-port energy router, which acts as the interface between the power consumer and the distribution network. The corresponding coordinated control strategy is developed to guarantee the regular operation of the energy router and a mode switch strategy with advanced compensation is proposed to achieve seamless transition between grid-connected mode and islanded mode. A novel and practical fuzzy logic controller considering unit-time electricity charge is proposed for the energy router to prolong battery life, to improve economic benefits of power consumers, and to smooth fluctuations of renewable energy generation or load consumption. The simulation and experimental results have validated the coordinated control and energy management strategies and demonstrated that the energy router has satisfactory performance.

Highlights

Due to the shortage of fossil energy and the demand for sustainable development, much attention has been paid to the development and utilization of renewable energy resource
In order to avoid the over charge of battery, the intelligent power switch (IPS) connected to distributed generation (DG) will be disconnected if SOC of ES battery (SOCESB) is above the upper threshold
This paper introduces a multi-port energy router (MER) which is applicable for lowvoltage distribution network

Summary

INTRODUCTION

Due to the shortage of fossil energy and the demand for sustainable development, much attention has been paid to the development and utilization of renewable energy resource. If AC part works in V-f mode, the controller will comprise the root mean square (RMS) loop and phase angle loop for each phase voltage to supply the three-phase sinusoidal output voltages with constant frequency and constant amplitude, and the fourth leg will be controlled by high frequency PWM signals with 50% duty cycle to deal with unbalanced load In this mode, if a microgrid is connected to the port of AC part, the grid-connected converter of microgrid is required to track the voltages generated by AC part. In grid-connected mode, closed-loop control of ES inductor current is employed, and the ES battery charging/discharging current reference value is obtained by energy management strategy which will be discussed in later chapter.

MODE SWITCH STRATEGY

DISCUSSION ON POWER FLOWS

ENERGY MANAGEMENT STRATEGY FOR GRID-CONNECTED MODE

CONCLUSIONS