SCADA supervises and controls devices; ADMS uses a network model to locate faults, reconfigure and optimize distribution; DERMS coordinates distributed resources such as solar generation, batteries and flexible demand. They do not replace each other: they build on one another, and SCADA is the foundation of the other two.
Short answer
- SCADA: acquires data from devices, shows it to the operator and executes commands. It answers “what is happening and what can I operate”.
- ADMS: uses that data together with an electrical model of the network to locate faults, propose or execute reconfigurations and optimize voltage. It answers “what should I do with the grid”.
- DERMS: coordinates distributed resources (generation, storage, flexible demand). It answers “how do I use those resources without affecting the grid”.
The three form a stack: SCADA is the foundation, the ADMS builds on it and the DERMS builds on both.
SCADA
SCADA (supervisory control and data acquisition) is the system that sees and moves the grid. It receives statuses, measurements and alarms from substations and field devices, displays them on screens with time stamps and lets you send commands such as opening or closing a breaker. Its architecture, its tags and its relationship with the substation automation system are explained in SCADA architecture, tags and historian and in SCADA vs SAS vs DCS vs HMI.
What SCADA does not do by itself: it does not know how the network is connected or what will happen if a device is operated. It shows the signal; the decision belongs to the operator. What each ICCP conformance block, 1 to 5, includes is in ICCP: Conformance Blocks 1 to 5 and What Each Does.
ADMS
The ADMS (advanced distribution management system) is the platform that brings together distribution management functions. The U.S. National Renewable Energy Laboratory (NREL) describes an ADMS as supporting the full set of distribution management and optimization functions, including fault and outage management and voltage and reactive power optimization.
What sets it apart is the network model: an electrical model (what is connected to what, with what impedances and what load) kept up to date with the real positions of the devices. With that model it can:
- Locate a fault from the signals of reclosers and indicators.
- Calculate a reconfiguration that isolates the faulted section and checks whether the alternate source can carry the load. It is the centralized version of FLISR, covered in FLISR: fault location, isolation and service restoration.
- Coordinate regulators and capacitor banks to hold voltage and reduce losses.
If the model does not match the real network, the ADMS calculations are wrong even if they look precise.
DERMS
The DERMS (distributed energy resource management system) is, according to NREL, a software platform that helps the utility operate the grid with the support of distributed energy resources. It gathers information from the devices, monitors them, aggregates them and controls them, and can offer services such as demand response and voltage regulation.
NREL also warns that the term is not standardized and can refer to different solutions, from those of a resource aggregator to those of a utility. Before contracting, ask for the concrete list of functions.
When a utility has both an ADMS and a DERMS, they work together: according to NREL, a utility DERMS with an ADMS can coordinate distributed resources to identify and mitigate grid problems. It is common for the ADMS to hold the network model and control the field devices, and for the DERMS to coordinate the resources.
Comparison
| SCADA | ADMS | DERMS | |
|---|---|---|---|
| Main function | Acquire data and execute commands | Manage and optimize the distribution network | Coordinate distributed resources |
| Uses an electrical network model | Not necessarily | Yes, it is its foundation | Yes, through the ADMS or its own |
| Who decides | The operator | The operator or the automation scheme | The platform, with rules and grid limits |
| Data it needs | Field signals and commands | SCADA data, topology and load | State of each resource and grid limits |
| Example result | Breaker-open alarm | Reconfiguration after a fault | Power limit sent to a group of plants |
How models are exchanged
For an ADMS, a DERMS and other applications to share the same network model, common information models are used. The IEC 61970-301 standard defines the Common Information Model (CIM), an abstract model of the objects of an electric utility intended to let applications from different vendors integrate with each other. In the field, devices speak protocols such as IEC 61850, IEC 60870-5-104 or DNP3 (IEEE 1815), which are compared in IEC 61850 vs IEC 104 vs DNP3 vs Modbus.
How to decide where to start
The usual sequence is the same as in distribution automation: first a SCADA that receives statuses and measurements well, then tested remote commands and, only after that, an ADMS that automates decisions on that basis. A DERMS makes sense when there are already enough distributed resources to coordinate. Skipping a step usually produces costly systems that run on poor data.
What each one needs from the field layer
- Signals with the same meaning at every level. A status “open” in the device must be “open” in SCADA and in the ADMS model.
- Reliable communications. Without a link, the most complete tool only sees the last reading.
- Tested commands. Every command an ADMS will be able to issue is tested beforehand, end to end.
- Security. More remote functions means more attack surface; zones and conduits are applied as in OT network segmentation.
To go further, see the general picture of the smart grid, the layers that make up a smart grid, the digital twin of a power grid, metering data and analytics and how microgrids operate.
How we help
At Tiza Group we work on the layer where these systems depend on the field: we configure control and protection devices, build the signal map toward SCADA, configure gateways and test point to point. If you are integrating equipment from several manufacturers, we start with SCADA integration and gateways; for remote configuration of relays and controllers, see remote relay configuration. Tell us about your project and we will quote it.
Related guides
- What is a smart grid and how does it work?
- Smart grid components: layers and equipment
- Digital twin of a power grid: what it is and what it needs
- Substation SCADA and HMI system
- Distribution automation: reclosers and FLISR
- ICCP: Conformance Blocks 1 to 5 and What Each Does
References
- NREL, reports on ADMS and DERMS (docs.nrel.gov/docs/fy19osti/72108.pdf; docs.nrel.gov/docs/fy22osti/80904.pdf; docs.nrel.gov/docs/fy25osti/92831.pdf).
- IEC 61970-301, Common Information Model (CIM) base (webstore.iec.ch/en/publication/62698).
Frequently asked questions
Does an ADMS replace SCADA?
No. The ADMS receives data from SCADA and other sources, combines it with the network model and calculates actions. Without the SCADA acquisition and control layer, the ADMS has no field data and no way to execute its commands.
What is the difference between a DMS and an ADMS?
The term ADMS (advanced distribution management system) groups distribution management functions in a single platform, such as fault management, outage management and voltage and reactive power optimization. In practice vendors use both names with similar scope; what counts is the list of functions you contract.
Does a solar plant need a DERMS?
A single plant is normally managed with its own power plant controller and its SCADA. A DERMS makes sense when an operator must coordinate many distributed resources with different owners: decisions are made as a group, not device by device.