Grid Management System – A Key Enabler of Grid Modernization

By Moein Lak, Anthony Johnson, Brenden Russell, and Manuel Avendano

Southern California Edison Company (SCE) is one of the largest electric utilities in the United States with more than 130 years of history. SCE is regulated by the California Public Utilities Commission (CPUC) and the Federal Energy Regulatory Commission (FERC). SCE’s service territory covers 50,000 square miles across Central, Coastal and Southern California and serves 15 million residents in service territory and 5 million customer accounts.

SCE maintains and operates a vast electrical distribution system with more than 1.4 million power poles; 118,000 miles of distribution and transmission lines; 900 substations and 4,500 distribution circuits and, 20,000 distribution automation devices including remote automated reclosers, remote circuit switches, programmable capacitor banks, and voltage regulators. SCE has 4 distribution operation centers (DOC), 14 switching centers, 2 grid control centers (GCC), and additional centers to support telecommunications, security, and grid applications.

Approximately 46 percent of the electricity that SCE delivers to customers comes from carbon-free resources, including solar and wind. On average, more than 3,600 rooftop solar installations are connected per month. Consequently, distributed solar PV is expected to nearly triple by 2030, reaching 7,610 MW, and electric vehicle load at peak charging hour is projected to reach 836 MW.

SCE’s vision is to transform its electric system into a flexible and networked platform that empowers customers with options to provide grid services by leveraging Distributed Energy Resources (DER) through active grid management to meet the goals of safety, reliability, resiliency, decarbonization, and affordability. The following are primary investment drivers of this vision which will evolve over the next years:

• Obsolescence and compliance: SCE’s grid modernization investments focus on addressing immediate needs in the areas of asset obsolescence and complying with Distribution Resource Plan (DRP) requirements.
• High DER Penetration in SCE Grid: As DER connections to distribution system grow, ensuring there is enough hosting capacity and operating flexibility will become more of a focus.
• Evolving Distribution Markets: As distribution markets take shape, SCE will need to make sure it has the systems and tools in place to support it.

The twenty-first century electric energy infrastructure will require enhanced situational awareness, automation, reliability, resiliency, safety, and the ability to seamlessly integrate DERs. At SCE, we are implementing a next-generation Grid Management System (GMS) as the overarching solution to address these changes and anticipate future demands on the system.

Grid Management System

The GMS is a system of systems (SoS) which provides a comprehensive grid management solution to address an increasingly complex distribution environment. It replaces the existing Outage Management System (OMS) and the obsolete legacy Distribution management System (DMS). The GMS solution will be capable of adapting to SCE's evolving business strategies and will enable grid users to effectively respond to real-time information by providing situational awareness and perform varieties of real-time studies.

The GMS will feature a highly resilient, cyber-secure, interoperable, and flexible design. It will incorporate comprehensive solutions and feature a flexible framework allowing upgrades and enhancements to the best solutions available in the future. A parallel effort to the GMS is to replace SCE’s existing legacy communication system. This effort will utilize modern communication technology with enhanced cybersecurity functionality to provide a robust and affordable communications infrastructure.

The GMS is composed of the following key components:

Advanced Distribution Management System (ADMS) – Provides self-healing circuit functionality (FLISR), assisted switching for planned and unplanned outages, electrical system optimization, real-time power system studies and, reporting capabilities and SCADA controls. ADMS retrieves, manages and updates the electrical grid model up to the sub-transmission level. Mobile Grid Operations is another ADMS capability that provides field personnel access to grid data and the ability to update the grid information. 

DER Management System (DERMS) – Optimally manages and dispatches DERs to provide grid services, facilitates non-wires alternatives, enables DERs to participate in markets, meet Rule 21 smart inverter requirements, and cost-effectively manages distribution deferral resources. DERMS enables enhanced situational awareness under increasing DER penetration by providing DER modeling, aggregation and grouping. The DERMS also enhances the utilization of DER by providing DER communication, forecasting, DER enhance grid reliability services and DER constraint management.

Advanced Applications:

• Grid Device Management – Manages Intelligent Electronic Device access, configuration, maintenance, data retrieval, and the addition and removal of SCADA points. Devices to be managed include electric vehicles.
• Grid Optimization Engine – Optimizes distribution grid reliability and economics using inputs from the rest of the GMS systems. Optimizes use of SCE and aggregator-controlled DER.
• Short Term Forecast Engine – Estimates load and generation for the distribution grid under normal, abnormal, peak and contingency conditions. This analysis is performed utilizing the information available from the GMS historian, weather and environmental data inputs as well as incorporating DER forecast data provided from DERMS.
• Data Historian and Analytics – Archives grid data as well as providing data analysis capabilities. Provides historical data to the GMS and other systems.
• Business Rules Engine – Supports system-wide consistent operation and execution of policies and operational practices by managing business rules for the ADMS and other systems.

Advancing Grid Management System Efforts

SCE has advanced its GMS efforts through technology demonstrations funded by the Electric Program Investment Charge (EPIC), which is a ratepayer-funded program that supports the development of new, emerging, and non-commercialized clean energy technologies in California. For example, the findings of several demonstration projects informed the technical requirements of the ADMS and DERMS; identified the best approach for grid controls and communications; helped develop SCE standards for substation IT network design; and advanced the development of remote fault indicator, remote integrated switch, self-registering devices, and high-impedance fault detection technologies.

SCE has completed an extensive Request for Proposal and identified a preferred vendor for its GMS solution in 2019. The capabilities listed above will be implemented in phases and following standard system engineering lifecycle principles to minimize complexity of deployments. The GMS delivery roadmap focuses initially on ADMS functionalities followed by DERMS functionalities:

1. Distribution SCADA functionalities: Distribution Volt/VAR Control and Tie Device Restoration Logic.
2. OMS functionalities: Replace OMS functions with optimized outage management and notification processes, fully integrate distribution electronic switching management with a consolidated Transmission and Distribution switch management application, deploy mobile ADMS field functions.
3. DMS functionalities: Deploy advance distribution network analysis functions, deploy assisted switching and automated switching (FLISR, Protection Validation), Automatic Wire Down Detection and Isolation, basic DER management functions (IEEE 2030.5 aggregator dispatch).
4. Base DERMS functionalities: ADMS enhancements, next generation integrated ADMS and DERMS grid operator user interface, distribution automation management, base short-term forecasting (load and generation), base DERMS functions, base single interval optimization.
5. Advanced DERMS functionalities: Advanced DER management, optimal power flow, advanced short-term forecasting, IEC 61850 configuration tool.

All things considered, advanced distribution management systems in concert with field devices will improve safety, operational efficiency, and DER integration. SCE’s Grid Management System is a foundational grid modernization investment necessary for realizing the expected benefits of the accelerating industry transformation.

 For a downloadable copy of August 2019 eNewsletter which includes this article, please visit the IEEE Smart Grid Resource Center.