In the first 15 years of the 21st Century there has been a steady growth in Microgrids driven by a number of factors including geography, resilience, and location specific economics. In the last five years this growth has accelerated as the cost of renewables and storage have dropped significantly allowing for integration of these distributed energy resources (DER's) into Microgrids. A key to this trend has been intelligent, cybersecure microgrid control solutions (MCS) which have algorithms that can execute sophisticated control strategies that manage power flows safely and optimally. It is the MCS which is the nervous system of the microgrid and the platform upon which Microgrids are becoming a mainstream and scalable energy solution.
2. 2Proprietary
Islanded
Microgrid
Primary Energy
Source
Local Energy Sources
Local Community
“A group of interconnected loads and distributed energy resources with clearly
defined electrical boundaries that acts as a single controllable entity with
respect to the grid and can connect and disconnect from the grid to enable it to
operate in both grid-connected or island mode.”
Department of Energy Microgrid Definition:
Multiple Sources, Multiple Loads
4. IEEE 2030.7 Standard for the Specification
of Microgrid Controllers
Interoperability
Modularity
Define Key
Functions
Facilitate wide
adoption
Interface
Configurations
7. Microgrid Control System Cybersecurity and Trade-Offs
Source: Hudgens, Bryan; Hartner,Cameron; Adams, Brian; Regnier, Eva; Proceedings of the 52nd Hawaii InternationalConference
on System Sciences | 2019; “Investing in Cyber Defense: AValue-Focused Analysis of Investment Decisions for Microgrids,”
9. A robust microgrid control system allows for future growth
REMOTE
CUSTOMIZABLESCALABLE
ADAPTABLE
Pilot systems can be leveraged
for future microgrid design
Modular system easily adds
new loads or assets to microgrid
A microgrid is a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid.
Typicall four primary elements of a Microgrid: 1) Generation Assets; 2) Loads 3) Electrical Infrastruicture and Switches; and 4) Microgrid Control System
Generation and Storage is the largest cost (X% to Y%)
Electrical Infrastructure (switchgear, relay and utility iterconnecdtion) usually the 2nd most expensive
Microgrid Controller generally the smallest cost element.
These costs will driven not by cost of hardware and software but by the engineering time required to satisfy customer specific use cases and contingencies.
Economies of scales can certainly be realized for the control system if the use cases and contingencies are relatively similar. For example 250 kW Wind-Storage microgrid, might well have controller costs that are within 10-20% of a 2.5 MW microgrid----- provided the use cases are similar. Conversely, Large Microgrids do not necessarily result in economies of scale for the Microgrid Control Piece if there are complexities in use cases or if the asset set is significantly different.
Sandia National Lab developed a model for different types of Microgrids and estimates MG Controller at 15% of overall project costs
What is the definition of a Microgrid Control System, or, alternatively, a Microgrid Energy Management System
Microgrid control system: A system that includes the control functions that define the microgrid as a system that can manage itself, operate autonomously, and connect to and disconnect from the main distribution grid for the exchange of power and the supply of ancillary services;
What is the purpose of the IEEE standard for the Specification of Microgrid Controllers
Standard applies to Microgrids with a single point of connection to the Distribution Grid
What it DOESN’T DO
Prescribe Sizing of MG Components or Voltages at Interconnect
Protection schemes
Power exchanges at the Point of Interconnect
Communication Systems
There are two primary CORE Functions of a Microgrid Control System: Dispatch and Transition
The dispatch function includes the dispatching of microgrid assets and providing them with appropriate setpoints. It directs the use of the distributed energy resources available within the microgrid and ensures the proper operation of the microgrid, both internal to the microgrid and as seen by the grid at the POI with the distribution system.
The transitions shall consider, as shown in Figure 4: a) Unplanned islanding (T1) b) Planned islanding (T2) c) Reconnect (T3), with as applicable d) Black start (T4)
Again, the two CORE functions of a Microgrid Control System are 1) Transition; and 2) Dispatch
Any microgrid control system shall perform appropriate actions for the mode of operation of the microgrid, either steady state grid connected, steady state islanded, or during transitions between grid-connected and islanded modes.
In this standard, the required behavior of the microgrid control system is discussed in terms of the functions it must perform. The core functions of the microgrid control system are the minimum functions necessary to meet the description of a microgrid as defined in this standard and based on the objectives listed above. The functions are abstract, and can reside anywhere within the physical microgrid control system. These functions are not necessarily limited to any particular physical control devices, and can be realized in centralized, decentralized, or hybrid architectures.
Source: Proceedings of the 52nd Hawaii International Conference on System Sciences | 2019
Investing in Cyber Defense: A Value-Focused Analysis of Investment Decisions for Microgrids
Greater functionality may diminish security
More automated control may limit user control
Investing in Cyber Defense: A Value-Focused Analysis of Investment Decisions for Microgrids
Two authors from Naval Post Graduate School and Two authors from the Marine Corp
What is contingency?
dependence on chance or on the fulfillment of a condition; uncertainty; fortuitousness:
Interesting that in the IEEE standard the term “contingency” is mentioned one (1) time……………
I think Contingency Planning and Contingency Risk are often the most important consideration in the development of Microgrid Control Solutions
A customer needs an adaptable, scalable and flexible Microgrid Control System to accommodate inevitable changes. As you start adding more components and load to your Microgrid, it must be flexible. Adaptation to changing needs means each Microgrid may take on new attributes and so your system must scale to meet these new demands.
For Example
You need Scalability and flexibility for the first microgrid
This means that you have the ability to perform some configuration through a graphical user interface.
You want to be able to add further assets or loads without having to rewrite the entire underlying software. Using a modular platform which leverages a modern programming language as opposed to outdated legacy languages helps to achieve this.
Your control system needs bandwidth to accommodate additional control communications and data flow for expanding applications
So, in closing, I would argue that we may have already entered the Microgrid Age. Furthermore, I believe that there will be a major role for what we call “Remote, or Islanded Microgrids” here on Earth and that these unique types of Microgrids can provide a platform for Renewables Integration and Carbon Mitigation.
Finally, as we look to the sky again for manned space travel it is these Remote or Islanded Microgrids---and the Control Systems that intelligently regulate and operate these Microgrids-----that can provide valuable support for manned missions to the Moon and to Mars. There will be no electricity grid on Mars or on the Moon. The living space for astronauts will need to operate independently and autonomously----potentially over a long period of time.
