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.

No abstract

No abstract

This paper focuses on voltage control schemes for lowvoltage DC (LVDC) distribution systems that has been studied for electrification of rural sides in South Korea. Telecommunication repeaters on mountain tops can be a good application for LVDC systems because it needs DC power rather than AC and low-voltage distribution can reduce the operation and maintenance costs for distribution network operators (DNOs). However, lowvoltage distribution can suffer voltage regulation issues depending on the size of the systems. This paper presents the design concept of multi-agent based hierarchical control schemes for distribution voltage regulation and evaluation of the control performance by simulation studies.