How B. Braun Medical uses ETAP Intelligent Load Shedding for uninterrupted healthcare operations

• Identify necessary and optimal load shedding during network undervoltage disturbances
• Ensure that critical loads will operate continuously during outage events and in islanded mode
• Avoid the loss of manufacturing production, which results in both safety issues and costly downtime
• Prevent regulatory re-validations due to the unexpected shutdowns, which require hours to complete

Exploring load shedding improvements for critical production processes

The facility's existing system provided no optimization for load shedding, and loads were being shed sequentially resulting in all connected loads being shed during a disturbance. Without an intelligent load shedding solution, 90% of the time, a grid outage would result in the entire plan and process shutdown. 

Electrical Network

System Units:

• Source 1 - 2.7 MW – Generator 1
• Source 2 - 3.3 MW – Generator 2
• SCE Grid Connection

Interconnection to the Utility Grid:

• Entire facility is separated into two connections
• Switchyard A provides power to 12 substations and 2 large chillers
• Switchyard B provides power to 4 substations and 2 large compressors

Switchyard A has three sources which provide power to most of the facility, with Source 1 Generator providing approximately 2.7 MW. Source 2 is another generator that provides approximately 3.3 MW and the rest is carried out by the grid, which approximates 1.6 MW. The second part of the facility is powered from Switchyard B. This switchyard is currently only connected to the grid, and the facility was in the progress of installing a new onsite generation system to this switchyard. 

While the onsite generation was being commissioned, B. Braun simultaneously worked with ETAP to explore a load shedding system design to help maintain the critical loads to prevent any damage (physically and financially) to their electrical network.

The first portion of the case study was to develop an ETAP digital twin of the electrical system to help visualize their electrical network operation with two substations. The second portion of the case study was to analyze the implementation of an additional load shedding solution for their real-time operational control system. Because the majority of the facility is powered from Switchyard A, the case study focused on the addition of load shedding to this switchyard with a mixture of critical, semi-critical and non-critical load categories.

ETAP Power Simulator - Easy to use, comprehensive network modeling, analysis and simulation software for high-voltage and low voltage power systems used to build a unified electrical digital twin of any electrical network and analyze load flow, short circuit, and many other analyses

ETAP Real-time Intelligent Load Shedding  (ETAP iLS) -  A fast, proactive and optimized load shedding solution for industrial facilities to preserve essential loads and avoid widespread system outages using power balancing and fast response that considers process and power system dynamics

• Clear visualization of the existing electrical network at the facility
• Simulation of their network with the proposed load shedding scheme
• Real-time, flexible and easy to use load shedding system with an HMI and including breaker statuses
• Dynamically updated and optimized load tables
• Immediate response to disturbances through continuous connection of load shedding solution to the controller

Using ETAP Power Simulator for electrical network load analysis, loads were categorized as critical, semi-critical, and non-critical to optimize prioritization of energy delivery. The digital twin of the network was used to evaluate the power quality and prepare safe load-shedding scenarios, based on the digital model.

Then the optimization scenario using ETAP Intelligent Load Shedding (iLS) was implemented, and load shed was successfully executed during the island scenario, providing both a continuous calculation and optimal load selection of the facility’s system. 

Now, before any event occurs, ETAP iLS is continually predicting and calculating which loads could potentially be shed, so that it can act instantly whenever a disturbance occurs. Load optimization is now based on priority, and ETAP iLS sheds loads that are close to the required load with a 3% maximum deviation. Because the facility can now use the ETAP environment to monitor and modify their load shedding configuration, process and planned shutdowns for manual modifications are minimized.  

Maintain critical system operations with real-time load shedding

• Cost savings of approximately $1 million USD per outage
• Outages no longer shut down essential power at the medical manufacturing facility
• Operations continue safely during islanded conditions using configurable load shedding to shed only minimum or optional loads
• Improved monitoring of operating conditions, including generation, grid import/export power, power consumption at each load shedding point
• Reduced time spent manually adjusting their electrical network and performing lengthy regulatory re-validations after outages
• Future upgrades and expansions can be accurately evaluated using digital simulations of their network

ETAP iLS continuously updates load-shedding tables and executes decisions in real-time, responding to disturbances in under 20 milliseconds.

Eric Ham, Senior Automation and Controls Engineer, ETAP