A Novel Voltage Control Scheme for Low-Voltage DC Distribution Systems Using Multi-Agent Systems

Trinh Hai,Hyun-Koo Kang,Hector Cho,Il-Yop Chung,Jintae Cho,Juyong Kim

doi:10.3390/en10010041

Abstract

Low-voltage direct current (LVDC) distribution systems have been evolving into interesting ways of integrating distributed energy resources (DERs) and power electronics loads to local distribution networks. In LVDC distribution systems, voltage regulation is one of the most important issues, whereas AC systems have concerns such as frequency, power factor, reactive power, harmonic distortion and so on. This paper focuses on a voltage control method for a LVDC distribution system based on the concept of multi-agent system (MAS), which can deploy intelligence and decision-making abilities to local areas. This paper proposes a distributed power flow analysis method using local information refined by local agents and communication between agents based on MAS. This paper also proposes a voltage control method by coordinating the main AC/DC converter and multiple DERs. By using the proposed method, we can effectively maintain the line voltages in a pre-defined normal range. The performance of the proposed voltage control method is evaluated by case studies and compared to conventional methods.

Highlights

IntroductionAmong various applications of DC distribution systems, low-voltage DC (LVDC) distribution systems, whose rated voltage is less than 1500 V, have unique strengths for distribution network operators (DNOs) in that they can supply diverse energy management services by integrating distributed generation or storage units into local distribution networks [2,3]
There have been studies into DC distribution systems that can bring advantages over conventional AC distribution systems in terms of energy efficiency, power quality and so on [1].Among various applications of DC distribution systems, low-voltage DC (LVDC) distribution systems, whose rated voltage is less than 1500 V, have unique strengths for distribution network operators (DNOs) in that they can supply diverse energy management services by integrating distributed generation or storage units into local distribution networks [2,3]
This paper proposes a new voltage control method by coordinating the main AC/DC converter and distributed energy resources (DERs) scattered in LVDC distribution systems

Summary

Introduction

Among various applications of DC distribution systems, low-voltage DC (LVDC) distribution systems, whose rated voltage is less than 1500 V, have unique strengths for distribution network operators (DNOs) in that they can supply diverse energy management services by integrating distributed generation or storage units into local distribution networks [2,3]. In LVDC distribution systems, voltage regulation is one of the most significant issues for their planning and operation because it mainly defines the quality of the distributed electricity. The main objective of voltage regulation is to maintain the voltage within certain ranges that can guarantee voltage stability and service quality of the distribution system. The normal voltage range is defined as ±5% of the rated voltage under the assumption that we need to supply the same voltage quality to the customers as AC distribution systems.

Methods

Results

Conclusion