ChargingStationExternalConstraints (OCPP)
An OCPP charging-profile purpose used to represent charging limits imposed by external actors like an Energy Management System (EMS) or a smart meter.
Technical Details
In OCPP 2.1 energy-management topologies, a charging station (or local controller) can translate a non-OCPP control signal (single limit or schedule) into an internal charging profile of purpose ChargingStationExternalConstraints (also described as “ExternalConstraints”). This makes external limits visible in an OCPP-native way so the CSMS can reason about why charging power changed.
Fleet Applications
Improves transparency in depot operations: the CSMS can distinguish between “vehicle doesn’t need power” and “site constraint throttled power,” enabling better scheduling, reporting, and troubleshooting.
Related Terms
Smart Charging
Intelligent management of EV charging sessions to optimize energy consumption based on grid constraints, energy prices, and vehicle schedule requirements.
OCPP 2.1
OCPP 2.1 is a newer OCPP release that extends the protocol ecosystem with clearer architecture guidance and energy-management integration patterns for smart charging deployments.
NotifyChargingLimitRequest (OCPP)
An OCPP message used by a charging station (or local controller) to inform the CSMS that the active charging limit changed due to an external source (e.g., EMS, smart meter, DSO signal).
Local Controller (OCPP)
An on-site component that can sit between charging stations and a CSMS to perform local scheduling and load balancing, often used when integrating an EMS at a site.
EMS as Man-in-the-Middle (OCPP)
An energy-management topology where EMS and local-controller functionality are combined and placed between the CSMS and charging stations.
Dynamic Load Management (DLM)
Real-time adjustment of charging power based on available site capacity and operational constraints.