html{display:none} Microgrid Control | Schweitzer Engineering Laboratories

Microgrid Control

SEL provides turnkey microgrid control systems that ensure resiliency, reduce energy costs, and integrate renewable energy generation.


Our systems include electrical system protection, automation, cybersecure networking, real-time controls, and visualization (HMIs). SEL control hardware works with almost all distributed energy resource (DER) interfaces and can be fully integrated with existing electrical infrastructure.

SEL is the global leader in microgrid control systems, verified by rigorous independent evaluations and proven by 15+ years of performance in the field. Our powerMAX Power Management and Control System maximizes uptime and ensures stability, keeping the microgrid operational even under extreme conditions.

Organizations of all kinds can benefit from implementing microgrids. But microgrids are not one-size-fits-all; they can provide value in varying ways.

Energy Resiliency for Critical Infrastructure

SEL microgrid control systems ensure the reliable, resilient delivery of electric power for critical infrastructure in many different areas:

  • College campuses—integrate on-campus generation, keep the lights on, and protect critical facilities and research projects.
  • Military bases—provide power system reliability and survivability with SEL powerMAX garrison microgrids and mobile tactical microgrids.
  • Emergency services—keep hospitals, fire stations, police, and community centers operating during natural disasters and public emergencies.
  • Data centers—provide an uninterrupted supply of high-quality electric power to keep servers running and data flowing.
  • Manufacturing plants—keep critical processes running, and eliminate costly downtime.
  • Commercial centers—keep the lights on and businesses running.
  • Utility providers—implement microgrids at the distribution level to integrate DERs, keep emergency services powered, and improve reliability metrics.

Key Features of a Resilient Control System

Seamless Islanding

SEL powerMAX microgrid control systems quickly and seamlessly island the microgrid if the utility connection fails and automatically resynchronize when it’s time to reconnect. Subcycle, inertia-compensated powerMAX control algorithms prevent blackouts, even when closely timed events occur.

For instance, on a research campus, buildings that house biocontainment facilities cannot be allowed to lose power even momentarily. These facilities (whether a single building or a group of them) may operate like several smaller microgrids nested inside the larger, campus-wide microgrid. While this provides resiliency, it dramatically increases the control complexity. SEL powerMAX microgrid control systems are able to seamlessly handle multiple closely timed events in overlapping control zones.

Protection of Critical Assets

SEL advanced control systems respond quickly and accurately to the rapidly changing power system dynamics of microgrids. Fast, intelligent load shedding and inertial compensation ensure that generation sources and other critical assets (e.g., transformers and points of common coupling between the utility and inverter-based sources) are protected under all operational conditions.

Reliable, Cybersecure Control Hardware

Strong cybersecurity defenses, with best-in-class secure networking, are integral to every SEL powerMAX microgrid control system.

We design and manufacture our control and protection hardware in the U.S.A., in facilities which we own and operate. All SEL control system components have a ten-year factory warranty—the best in the electric power industry.


Microgrids can help the larger electrical grid become more resilient to large-scale cyber attacks, as each microgrid control system is isolated from controls in other parts of the grid.

To secure the microgrid itself, layered cyber defenses are part of every SEL microgrid control system. The SEL powerMAX system uses software-defined networking (SDN) to eliminate common LAN security threats. The deny-by-default SDN security architecture routes operations traffic only through preconfigured communications paths within the LAN. This provides protection against attacks that occur inside the network and guards against unauthorized traffic that might slip past the firewall.

SEL also practices secure supply chain management in compliance with NERC CIP-013 standards.

We write every line of our own firmware code, and it is never shared outside the company, so there are no third-party vulnerabilities. All SEL devices are designed for a 20-year service life; we proactively notify product owners of updates and any vulnerabilities or security patches for the full life of the product.


Energy Cost Savings

With the SEL Microgrid Economic Dispatch Engine, a microgrid can automatically manage energy costs based on weather, fuel cost, utility rates, peak load times, and more. These factors can be predetermined or tied to dynamic inputs, such as market prices.

The microgrid control system also generates historical data that can be used for cost impact estimation and load and generation forecasting.

This allows you to implement energy storage and peak-shaving strategies to reduce energy cost and use renewable sources when they’re most advantageous.

Renewables Integration and Emissions Reduction

Microgrids can include any number of distributed renewable resources and integrate them with other generation sources, giving their owners many options for reducing carbon emissions and pollution.

Integrating Renewables

Wind and solar generation are variable and intermittent, which poses difficult challenges in a system that must supply reliable, consistent power. Aggregating them in a microgrid helps mitigate the problem by combining multiple sources into one generation output that is less variable than any single renewable source.

SEL control systems can proactively manage renewable sources, islanding them when necessary, managing battery storage, and metering and controlling their contribution to the rest of the grid.

Emissions Reduction

SEL microgrid controls allow you to augment existing traditional generation sources (such as natural gas) with wind and solar. This gives you a practical way to tackle emissions reduction at a local level—ensuring reliable, high-quality electric power with a smaller environmental footprint.

Distributed Control Vs. Centralized Control

In addition to our powerMAX microgrid control systems, SEL offers a robust distributed control solution that is suitable for smaller microgrids with a simple bus configuration.

Distributed Control

A distributed control system uses the built-in coordination capabilities of SEL relays to control and protect the microgrid. It is applied in microgrids with a simple bus configuration (flat topology), usually with less than 1 MW of generation and few renewable generation sources. Reciprocating engines and inverters are typical generation sources.


  • Military garrisons and forward operating bases—simplicity and efficiency for greater mission capability.
  • Mobile microgrids—simplified control of mobile generation and load distribution.
  • Small community microgrids—control, islanding, and resynchronization of a single-bus feeder circuit with minimal DER integration.

Centralized Control

Centralized control is typically necessary in microgrids with more than 1 MW of generation capacity and those with extensive DER integration.

An SEL Real-Time Automation Controller (RTAC) with customized powerMAX control logic and the SEL Microgrid Economic Dispatch Engine coordinates the functions of the microgrid system and provides generation dispatch, load shedding, islanding, and resynchronization.


  • College campuses, hospitals, data centers, and manufacturing plants—ensure resiliency and cost effectiveness; make sure critical loads stay online.
  • Military bases—maximize resiliency and mission capability with distributed generation control and improved fuel efficiency.
  • Community microgrids with multiple distribution circuits—integrate renewable resources, ensure resiliency, and reduce energy costs.

SEL Microgrid Economic Dispatch Engine

We integrate cost optimization strategies into every microgrid control system we design, ensuring that you get the most economical results possible within the operating philosophy you’ve chosen.

The SEL Microgrid Economic Dispatch Engine accounts for the various modes of operation of multiple DERs and determines the most economical dispatch based on factors such as the internal dynamics of the microgrid, energy cost, and desired operating philosophy.

The dispatch engine maximizes your microgrid’s return on investment (ROI) by allowing you to take advantage of:

  • Cost factor management.
  • Load and generation forecasting.
  • Dispatch scheduling.
  • Historical analysis and cost impact estimation.

By ensuring stability in all scenarios, SEL microgrid controls deliver the industry’s most cost-efficient results.

How We Ensure Microgrid Success

We partner closely with microgrid owners and their contractors and integrators in planning, testing, and commissioning the control system. Our collaborative process sets clear, mutual expectations and a solid plan up front, so you can trust that there won’t be change orders, delays, or surprise costs on the back end.

Every SEL microgrid control system is specifically engineered to meet your desired energy management and economic outcomes, starting with either a front-end engineering and design (FEED) study or an investment-grade audit.

The FEED Study

This affordable study helps define the desired operating philosophy, identify what’s feasible, and outline how the control system design will achieve the desired objectives.

The FEED study findings and recommendations cover topics such as:

  • Site survey and document review covering the existing power system and any risks and limitations.
  • Specifications for procurement of control, protection, and other equipment.
  • Detailed description of the control solution, providing clear expectations for what will be delivered.
  • Scope of work and a detailed price quotation.

With the FEED study in hand, you will be able to make an informed decision on what your ROI will look like when you move forward with your microgrid project.

Rigorous Reliability Testing

We treat every powerMAX microgrid control system like a custom solution, specifically engineered to integrate with existing resources, protect valuable primary equipment, ensure safety, and achieve your desired economic and energy management outcomes.

SEL ensures system reliability through comprehensive hardware-in-the-loop testing performed in our Real Time Digital Simulator (RTDS) facility. Our customers are always invited to participate.

With the actual SEL hardware that will control your system installed in the RTDS test bed, we use our extensive library of validated power system models to run a multitude of tests—including scenarios too disastrous to test in the field—and verify that the microgrid controls perform exactly as designed, even under adverse conditions.

This testing process also helps us simplify commissioning the system, so there are no delays or unforeseen costs in the field.

The Best Microgrid Control Systems—Tested and Proven

Independent third-party evaluations—and performance in installations around the world—verify the effectiveness and reliability of SEL powerMAX microgrid systems.

The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) chose an SEL control system for their research microgrid in a rigorous 21-week competitive procurement program.

To ensure the best possible control system for their research microgrid, which tests emerging technologies, NREL rigorously tested all competitors on their ability to deliver stable, cost-effective operation. The SEL powerMAX microgrid control system demonstrated a superior ability to make quick control decisions and maximize economic benefits under a wide range of operating conditions.

Navigant Research also selected SEL as the world leader in microgrid controls in their “Navigant Research Leaderboard: Microgrid Controls” report.

Navigant Research Grid

SEL Solutions in Action


MSU Featured

Microgrid Solution Plays Big on Campus

An SEL protection and control system integrates Montclair State University’s on-campus generation and distribution systems with the regional utility grid, while also allowing the campus to operate as an islanded microgrid if necessary.


Microgrid System Ensures Critical Research Facilities Always Have Power

A powerMAX protection and control system at the University of California, San Diego—one of the ten largest research campuses in the USA—detects unstable conditions in the main grid and quickly islands itself, ensuring that critical loads like Scripps Institution of Oceanography (SIO) and the UC San Diego Health System don’t lose power.


SEL Helps Duke Energy Achieve Microgrid Simplicity

Questions? Contact Us!

We’re happy to answer all your questions and help develop the best solution for your needs.

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Unbeatable Support

Every SEL solution comes with lifetime technical support, free of charge.

There are no service contracts, time limits, or expiration dates. No matter how often you call or how long your SEL products have been in service, you’ll reach a friendly human who can provide the service and support you need.

Our support teams are stationed in regional offices around the world and staffed with application engineers who are experts in our products and in power system applications. We’re always ready with the information and resources needed to keep your SEL solution working effectively.