GridAPPS-D Introduction

What is GridAPPS-D?

GridAPPS-D™ is an open-source platform that accelerates development and deployment of portable applications for advanced distribution management and operations. It is built in a linux environment using Docker, which allows large software packages to be distributed as containers.

The GridAPPS-D™ project is sponsored by the U.S. DOE’s Office of Electricity, Advanced Grid Research. Its purpose is to reduce the time and cost to integrate advanced functionality into distribution operations, to create a more reliable and resilient grid.

GridAPPS-D enables standardization of data models, programming interfaces, and the data exchange interfaces for:

devices in the field
distributed apps in the systems
applications in the control room

The platform provides

robust testing tools for applications
distribution system simulation capabilities
standardized research capability
reference architecture for the industry
application development kit

GridAPPS-D Platform Characteristics

Vendor / Vendor Platform Independent

The GridAPPS-D Platform and application development environment is independent of any specific vendor or vendor platform, in other words vendor neutral. The results of this effort are intended to be useful and available to any vendor or application developer who wishes to apply them or incorporate them into existing or future products.

Standards-based Architecture

GridAPPS-D is the first platform for energy and distribution management systems that is designed with standards for data integration, including data models, programming interfaces, and data exchange interfaces between grid devices in the field, distributed applications in utility systems, and applications in utility control rooms. This means that the applications developed using GridAPPS-D make them broadly applicable and interchangeable across utility systems, reducing the cost and time for utilities to integrate new functionality.

To the greatest extent possible, the GridAPPS-D Platform incorporates and supports industry standards, in particular interoperability standards, including the power system model representation using the Common Information Model (CIM) and communications with other platforms / physical equipment through DNP3, IEEE 2030.5, and the open field messaging bus (OpenFMB)

Replicable

As a reference implementation of a standards-based architecture, advanced applications and services developed with GridAPPS-D Platform should be replicable, with the ability to be deployed at multiple locations on different distribution feeders with almost no code customization.

Flexible Distribution Simulation

The GridAPPS-D Platform enables users to run real-time quasi-static simulations of large distribution network models with real-time load data, thermal co-simulation of houses, real-time weather data, and real-time operation of switches, DERs, and volt-var control equipment. The platform supports multiple distribution simulators through a co-simulation bridge that abstracts the simulation configuration details to a simple API.

Data Representation & Management

A key to GridAPPS-D is providing the distribution system application developer with a standardized approach to data. The intent is to allow the developer to make logical references to data referencing standard data models and interfaces without concern for how the data is physically made available. This standardized, logical data interface is based on existing standards to the greatest extent possible.

Standards-based Data Representation

The Common Information Model (CIM) is used for all power system models, which enables rapid exchange of power system models across compliant applications and services. Using the set of standardized model queries provided by the PowerGrid Models API, a GridAPPS-D application is able to scale seamlessly across different network models with no modifications to the application code.

Standards-based Data Interfaces

The GridAPPS-D Platform and GridAPPS-D APIs provide a standardized method for interfacing with power system model data, real-time simulation data, historical data, and log data. Each of these APIs abstract the database specifics, and enable simple queries through a set of standardized messages formatted as JSON strings.

Data Translation to Non-standardized Elements

CIM Hub and the Configuration File API allow conversion of the power system model data from the standards-based CIM XML format used by the GridAPPS-D Platform to model formats used by other software packages, such as GridLAB-D and OpenDSS. This model conversion process can be performed with a simple set of standardized API calls.

Available Distribution Feeders

The GridAPPS-D platform comes pre-configured with a combination of IEEE Test Feeders, PNNL Taxanomoy feeders, and other realistic synthetic models. Additional models and actual utility feeder data can be uploaded easily as CIM XML files into the GridAPPS-D Platform, which can then be used for application testing and real-time simulation.

Real-Time Distribution Simulation

The GridAPPS-D Platform inlcudes a robust real-time distribution simulator with comparable capabilities to a Dispatcher Training Simulator. This environment enables application developers to test algorithms and application code on both the standard realistic sythetic feeders pre-configured in the GridAPPS-D Platform download and any other power system models that the user can upload through the CIM Hub package.

The distribution simulator is the source of data to the distribution system application developer enabling them to evaluate the performance of their application with ideal or realistic noisy data under different operating and performance conditions.

The GridAPPS-D platform currently supports only quasi-static simulation (i.e. simulation of electromechanical / electromagnetic transients, variable microgrid island frequency, synchro-check relays, etc. are not supported currently). These types of simulations can be performed with GridLAB-D outside of the the GridAPPS-D Platform and application development environment.

Real-Time & Faster-than-Real-Time Simulation

Simulations can be run in two modes:

Real-time mode: one second of computer clock time corresponds to one second of simulation time. The GridAPPS-D Platform runs the simulation in each time and publishes simulation data and sensor measurements every three seconds.
Faster-than-real-time mode: The GridAPPS-D runs the simulation as fast as possible and does not wait for three seconds of computer clock time to pass before it publishes the simulation data from the current time step. This mode is very useful for creating historical training data sets for AI/ML applications.

Controllable Power System Equipment

All of the power system equipment can be controlled in real-time through the Simulation API, allowing applications to open/close switches, dispatch DGs / DERs, adjust setpoints of rooftop PV, adjust regulator taps, and turn capacitor banks on or off.

Noisy / Bad Data Injection & Communication Failures

The GridAPPS-D Platform supports the Sensor Simulator Service, which is able to inject noise, bad measurements, and data packet losses into the simulation output. The frequency at which sensors publish can also be adjusted and aggregated, allowing realistic representation of real sensors, such as AMI meters that publish data every 15 minutes, rather than at each simulation time step. This allows the user to train and evaluate applications with realistic measurement for meters and sensors, rather than “pure” data created by the power flow solver.

The GridAPPS-D Platform also supports simulation of communication failures through the Test Manager during which data is not received from sensors, control commands are delivered to selected equipment, or both. This enables application developers to test algorithm performance under realistic conditions, during which physical equipment might not respond to control commands.

Reconfigurable Power System Topologies

The GridAPPS-D Platform supports simulation of both meshed and radial power system topologies, as well as reconfiguration of the power system network in real-time by opening / closing / tripping of various switching devices, such as breakers, reclosers, sectionalizers, and fuses. These switches can be controlled by an application through the Simulation API or through the GridAPPS-D Viz GUI

Real-Time Simulation Visualization

The GridAPPS-D Platform includes the Viz GUI application, which presents a simple graphic user interfaces with some of the basic functionalities found in an Dispatcher Training Simulator, inlcuding a one-line diagram of the feeder, colorized switch positions, outage locations, alarm messages, and customizable stripcharts of power flow, node voltage, and tap position.

Using the GridAPPS-D Platform

GridAPPS-D currently runs in a Linux virtual machine (VM). Although it can be built from sources, the primary form of distribution is as a set of Docker containers. Users can install the Docker infrastructure on their computer and then download the Docker containers. Several platform usage scenarios are then feasible:

Start and run the application through its browser interface. Utilities could use the platform this way to evaluate new applications, or to evaluate applications on their own circuits. The App Hosting Manager allows a user to install and configure new applications to run in the platform, by modifying configuration files but without having to write new code. GridAPPS-D will also be able to ingest any distribution circuit provided in CIM format.
Write scripted scenarios and responses using the Test Manager, and run those through GridAPPS-D. This mode can be used for a more rigorous evaluation, and also for operator training.
Write a new application, using one of the open-source examples as a template. This mode should provide a faster on-ramp for application developers to develop a standards-compliant product.
DMS vendors can use the platform to develop and test their own standards-compliant interfaces. Any GridAPPS-D code may be incorporated into a commercial product, pursuant to its BSD license terms. The goal is for an application to be deployable from one platform to another, simply by moving the program file(s) and updating local configuration files.