On the Cyber-Physical Needs of DER-based Voltage Control/Optimization Algorithms in Active Distribution Network (original) (raw)

With the increasing penetration of distributed energy resources (DERs) and extensive usage of information and communications technology (ICT) in decision-making, the mechanisms to control/optimize transmission and distribution grid voltage would experience a paradigm shift. Given the introduction of inverter-based DERs with vastly different dynamics, real-world performance characterization of the cyber-physical system (CPS) in terms of dynamical performance, scalability, robustness, and resiliency with the new control algorithms require precise classification and identification of suitable metrics. It has been identified that classical controller definitions, along with three inter-disciplinary domains, such as (i) power system, (ii) optimization, control, and decision-making, and (iii) networking and cyber-security, would provide a systematic basis for the development of an extended metric for performance evaluation of DER controllers; while providing the taxonomy. Majority of the control algorithms operate in multiple time scales, and therefore, algorithmic time-decomposition facilitates a new way of performance analysis. Extended discussion on communication requirements with the algorithmic architectural subtleties is expected to identify the real-world deployment challenges of voltage control/optimization algorithms in terms of presence of cyber vulnerabilities and associated mitigation mechanisms affecting the controller performance with DERs. Detailed discussion provided identifies the modeling requirements of the CPS for real-world deployment, specific to voltage control, facilitating the development of a unified test bed. INDEX TERMS Cyber-physical systems, Cyber-Security, Renewable energy sources, Taxonomy, Voltage control I. INTRODUCTION A S more and more small-scale inverter-based clean distributed energy resources (DERs) are being integrated, the power distribution system has become an active distribution network (ADN). Despite the known advantages of environmental friendly DERs, impacts of increasing penetration of is visible in the demand profile [17], [18]. The subsequent impact on the voltage profile is also prominent [19], and the resulting over-voltage condition during the day has significantly impacted the reliability of the grid. Contrarily, frequent operation of traditional voltage control devices, such as on-load tap changing transformers (OLTCs), voltage regulators (VRs), capacitor banks (CBs), etc., would significantly reduce their life span. While DERs can contribute towards voltage control within the ADN, lack of proper coordination among voltage control devices [20] would be detrimental towards power systems operation. Furthermore, with increasing number of devices connected