Self-Healing control strategy; Challenges and opportunities for distribution systems in smart grid

Implementation of self-healing control system in smart grid is a persisting challenge. Self-Healing control strategy is the important guarantee to implement the smart grid. In addition, it is the support of achieving the secure operation, improving the reliability and security of distribution grid, and realizing the smart distribution grid. Although self-healing control system concept is presented in smart grid context, but the complexity of distribution network structure recommended to choose advanced control and protection system using a self-healing, this system must be able to heal any disturbance in the distribution system of smart grid to improve efficiency, resiliency, continuity, and reliability of the smart grid. This review focuses mostly on the key technology of self-healing control, gives an insight into the role of self-healing in distribution system advantages, study challenges and opportunities in the prospect of utilities. The main contribution of this paper is demonstrating proposed architecture, control strategy for self-healing control system includes fault detection, fault localization, faulted area isolation, and power restoration in the electrical distribution system.

I. Introduction

Smart grid is a modernized, complex environment that is composed of different kinds of nodes, devices, networks, systems, and numerous applications [1]. Smart grid generally has main five features; self-healing, automation interaction, optimization, compatibility, renewable energy integration [2]. Self-healing is the most important feature of the smart grid. This capability provides the fastest return on investment for smart grid [3]. The self-healing feature refers to continuously self-assessment of the grid operation, rapidly detect, diagnosis, timely isolation of incipient faults with and without human intervention and adopt corrective actions to prevent cascade failure. Self-Healing automation systems typically need to reconfigure the system within a short period of time. It offers multi-flexible control features allowing the utilities to leverage existing power grid infrastructures and upgrade to smart grid infrastructure. The self-healing grid requires a robust real-time computation system that monitors, processes, provides predictive analytics, performs and makes faster decisions to detect, locate, and isolate various faults, reconfigure and reroute power of the distribution network to minimize service disruptions and outages. Figure. 1 presents the investments worldwide in developing management systems of the power outages for the period 2014–2018. It reveals a substantial increase in the investment costs over time [4]. Smart grid faced with a number of challenges can be divided into eight main challenges, technology development, quality power, transmission and distribution loss, renewable energy integration, interoperability, cyber security, data monitoring and management, consumer support and self-healing implementation [5]. Many researches have focused on the significance of self-healing for distribution system [6]–[8]. Other studies have been carried out on the power grid architecture [9], self-healing control system and challenges in power networks operation [10], self-healing control in smart distribution grid and improving consumer participation [11]. At present, there is still no efficient, comprehensive strategies to self-healing capability and restoration functionality in smart grid distribution system, considering the self-healing control system reliability, dynamics of complex power networks to maintain quality of service, enhance the reliability and stability operations of the smart grid, allow power outage anticipation. The self-healing control in smart distribution network is still in the exploratory stage [12]. The existence of electrical faults and disturbances is inevitable in the grid, whereas the potential damage consequences mainly depend on the magnitude of the fault, the type, duration, and location of the fault [13]. An important feature of the smart grid vision is its ability to identify and mitigate faults, predict failures in the grid, adjust the protection automatically, and control the electric network in real time. The buildout of a SG requires the use of robust network for ensuring reliable and continuous operation. The self-healing feature of smart grid provides fastest return on investment (ROI) [14]. When developing a smart grid, the advanced self-healing operation through multilevel control and infrastructure optimization of the electric utility is essential. This allows unlocking the full potential of the grid by realizing sophisticated measures to detect faults through the utilization of real-time data and thus ensuring reliable and safe operation. Also, the detected faults can be isolated for reconfiguring the network and minimizing the number of impacted customers [15]. Therefore, this paper presents a comprehensive study of implementing an adaptive and optimized strategy through the proposed self-healing control system in distribution network, and explained it's impact on smart restoration process of the grid operation after detecting any disturbance or predicting any failure, whereas preserving system reliability. The main contribution of this paper is presenting the benefits of implementing self-healing control system as essential step to improve smart grid reliability and stability of the electrical grid. Fig. 1.

Market spending in management systems of utility power outages.

Fig. 2.

Smart electricity grid architecture