Tounsi Fokui Willy Stephen, Saulo Michael, Ngoo Livingstone
Department of Electrical Engineering, Pan African University Institute for Basic Sciences, Technology and Innovation, P.O. Box 62000-00200, Nairobi, Kenya.
Department of Electrical and Electronic Engineering, Technical University of Mombasa, P.O. Box 90420 - 80100, Mombasa, Kenya.
Heliyon. 2022 Mar 5;8(3):e09058. doi: 10.1016/j.heliyon.2022.e09058. eCollection 2022 Mar.
Over the past years, the penetration of photovoltaic (PV) systems into the distribution network has experienced significant augmentation as the pressure to reduce greenhouse gas emissions into the atmosphere keeps increasing while the prices of the solar components keep reducing. Despite the benefits PV systems bring to the distribution network, the high penetration of this technology into the distribution network could lead to reverse power flow (RPF) when the PV systems produce more than the local loads require. This RPF could result in the malfunctioning of protective devices and their coordination. This research addresses this problem by utilizing electric vehicles (EVs) that are currently revolutionizing the transport sector. Here, the charging of EVs during the day is intelligently controlled to mitigate RPF as a result of the excess power produced by the PV systems. Resolving RPF is achieved through a control system that measures the power flow on each phase of the main grid substation. If at any instance negative power is detected (reverse power), quantified EVs needing recharge are instantly incorporated into the network for charging through the automatic closure of the power switches of the required number of charging points with EVs whose total power demand equals the amount of reverse power detected. The excess power is hence absorbed and stored by the EVs. The proposed method is tested on an expanded IEEE 13 node test feeder and simulated using ETAP software. Simulation results show the effectiveness of the proposed method in eliminating RPF which occurs from 10:00 am to 12:00 noon by connecting the required number of EVs during that timeframe. The proposed method involves the distribution network operators working in synergy with the transport sector to effectively solve the problem of RPF in the distribution network.
在过去几年中，随着向大气中排放温室气体的压力不断增加，同时太阳能组件价格不断降低，光伏（PV）系统在配电网中的渗透率显著提高。尽管光伏系统给配电网带来了诸多益处，但当光伏系统的发电量超过当地负荷需求时，该技术在配电网中的高渗透率可能会导致反向功率流（RPF）。这种反向功率流可能会导致保护装置及其协调出现故障。本研究通过利用目前正在彻底改变交通运输行业的电动汽车（EV）来解决这一问题。在此，通过智能控制电动汽车在白天的充电，以减轻光伏系统产生的多余电力导致的反向功率流。通过一个控制系统来解决反向功率流问题，该系统测量主电网变电站各相的功率流。如果在任何时刻检测到负功率（反向功率），则将需要充电的定量电动汽车立即接入网络进行充电，即通过自动闭合所需数量的充电点的电源开关，这些充电点所连接的电动汽车的总功率需求等于检测到的反向功率量。多余的电力因此被电动汽车吸收和存储。所提出的方法在扩展的IEEE 13节点测试馈线上进行了测试，并使用ETAP软件进行了模拟。仿真结果表明，所提出的方法在通过在上午10:00至中午12:00期间连接所需数量的电动汽车来消除反向功率流方面是有效的。所提出的方法涉及配电网运营商与交通运输部门协同工作，以有效解决配电网中的反向功率流问题。
