Smart inverters provide additional control capability to help optimize the operation of distribution systems. This paper proposes a framework for exact optimal active and reactive power dispatch of distributed photovoltaic (PV) generation, switched capacitors, and tap changers in large multi-phase unbalanced distribution systems. The objectives of the optimal dispatch are minimization of the energy loss, PV active power curtailment, and capacitor and tap changer switching operations, in addition to elimination of voltage violations and reverse power flow. The optimization problem is formulated in rectangular coordinates as a nonlinear, nonconvex problem. Effective computational strategies are proposed to allow the application of predictorcorrector primal-dual interior point method to solve optimization problems in real-time with a large number of constraints and variables, including discrete variables corresponding to switched capacitors and tap changers. The accuracy of the numerical solution and the ability to implement the proposed framework are validated using the unbalanced multi-phase IEEE 34-bus and EPRI 2,998-bus distribution systems with 15-minute load and PV data. The results show a significant loss reduction and complete removal of both voltage violations and reverse power flow.

To efficiently use the ubiquitous behind-the-meter distributed energy resources (DERs) in distribution systems for providing grid services, this paper presents a hierarchical control framework for DER optimal aggregation and control. We first develop a convex optimization model to evaluate the DER flexibility, and then use a convex model-predictive-control based approach to dispatch those DERs. The hierarchical control framework consists of a utility controller, community aggregators and multiple home energy management systems. The flexibility of the DERs is evaluated by each controller in the hierarchy such that the resultant flexibility is feasible given its operational domain. Based on the determined flexibility, the hierarchical controllers then compute optimal setpoints for the DERs to help the distribution system regulate node voltages and provide other distribution grid services. Numerical simulations performed on a model of a real distribution feeder in Colorado, using actual DER data in a residential community demonstrate that the proposed approach can effectively alleviate voltage issues and support resilient operation.

Critical infrastructures like the power grid are at risk from increasing cyber threats due to high penetration of interconnected distributed energy resources (DER). Compromised DER endpoints can cause events, data breaches, communication loss, intentional device failures, and even cascading outages. To address these challenges, this paper explores cybersecurity issues in DER management systems (DERMS), including state-of-the-art reviews on architectures, communication protocols, access control privileges, data breaches, identity management policies, attacks such as false data injection, denial of service, distributed denial of service, malware, threats affecting data integrity, and network vulnerabilities. Realistic threat scenarios are outlined, followed by discussions on futuristic solutions like the zero trust framework. The paper presents new architectural patterns for recently released multi-level hierarchical framework as per IEEE 1547.3 standard to handle DERMS data and assets. The paper also discusses potential threats compromising the Confidentiality, Integrity, Availability, and Accountability (CIAA) properties at each level of the IEEE 1547.3 framework. This review is unique and comprehensive, as it covers existing research on cybersecurity challenges in DER-related assets and outlines the necessary capabilities to equip Intrusion Diagnostic Units (IDUs) in future DERMS technologies, all while ensuring compliance with IEEE 1547.3 standard requirements.

The aggregation of distributed energy resources (DERs) enables them to provide various grid services as a virtual power plant (VPP). Utilities use enterprise control solutions, such as advanced distribution management systems (ADMS) and distributed energy resource management systems (DERMS), to efficiently integrate DERs and realize the benefits of a VPP. These control solutions can complement each other to offer additional benefits. This paper evaluates the coordinated operation of an ADMS and a DERMS that collectively implements a VPP to provide peak demand reduction and voltage regulation through the simulation of an actual distribution feeder. A commercial ADMS reduces the peak demand through conservation voltage reduction (CVR). A prototype DERMS dispatches residential battery energy storage systems (BESS) based on real-time optimal power flow to provide additional peak demand reduction. The DERMS also maintains voltage regulation across the feeder by controlling both residential batteries and rooftop PV systems. The results from the controller-hardware-in-the-loop (CHIL) real-time simulations conducted in a realistic laboratory environment show that the coordinated operation of the ADMS and the DERMS effectively achieves peak demand reduction while enforcing voltage regulation across the feeder. Specifically, the ADMS dynamic voltage regulation (DVR) application and DERMS working together achieved a peak demand reduction of nearly 500 kW, whereas the ADMS DVR application alone obtained a reduction of approximately 100 kW. The DERMS VPP control in this work relies on the residential BESS for the demand reduction; the demand reduction accomplished depends on the BESS capacity available in the distribution system.

This paper evaluates the performance of coordinated control across advanced distribution management systems (ADMS), distributed energy resources (DERs), and distributed energy resource management systems (DERMS) using an advanced hardware-in-the-loop (HIL) platform. This platform provides a realistic laboratory testing environment, including accurate dynamic modeling of a real-world distribution system from a utility partner, real controllers (ADMS and DERMS), physical power hardware (DERs), and standard communications protocols. One grid service—voltage regulation—is evaluated to show the performance of the coordinated grid automation system. The testing results demonstrate that the coordinated DERMS and ADMS system can effectively regulate system voltages within target operation limits using DERs. The realistic laboratory HIL testing results give utilities confidence in adopting the grid automation systems to manage DERs to achieve system-level control and operation objectives (e.g., voltage regulation). This helps utilities mitigate potential risks (e.g., instability) prior to field deployment.

Reliable and resilient grid operations with high penetration levels of distributed energy resources (DERs) can be achieved with improved situational awareness and seamless integration of DERs with utility enterprise controls. This paper presents the details of the development of a data-enhanced hierarchical control (DEHC) architecture and the results of its evaluation. The DEHC is a hybrid control framework that enables the efficient, reliable, and secure operation of distribution grids with extremely high penetrations of solar photovoltaic (PV) generation by seamlessly integrating centralized utility controls, distributed controls for DERs, and autonomous grid-edge controls. In the DEHC architecture, the advanced distribution management system (ADMS) controls the legacy devices (such as load tap changers and capacitor banks), the PV smart inverters are dispatched by real-time optimal power flow, and the grid-edge devices regulate local voltages in coordination with each other. The DEHC is demonstrated using a commercial ADMS platform, real utility distribution feeder models, and grid-edge devices. The performance of the DEHC architecture is evaluated using simulations and hardware-in-the-loop experiments with voltage regulation as the control objective. The results show that the DEHC enables high penetration levels of PV in distribution feeders by effectively managing system voltages through the synergistic operation of ADMS, distributed PV smart inverter controls, and secondary-level grid-edge device control.