The text below is the transcript from the Smart Charging Connections: Locally Managed Constraint Scheme video.
Video Title: Locally Managed Constraint Scheme
A locally managed constraint scheme is required when chargepoint demand could potentially overload a single network location that can’t be managed by timed capacity limits.
To ensure that network capacity is not exceeded, a DNO local controller sends signals directly to the chargepoint operator’s chargepoint management system.
In this example, the town centre has three charging hubs supplied by the same network.
The multi-storey car park’s chargepoints have unconstrained connection and can charge at maximum power regardless of the town centre’s electricity load.
Similarly, the restaurant’s chargepoints are unconstrained and can charge at maximum power.
As more vehicles begin to charge, the town centre’s demand increases incrementally.
The high street charging hub is connected to the network via a locally managed constraint scheme which monitors the town centre supply’s available capacity.
With just one chargepoint in use on the high street hub, demand on the town centre supply is still relatively low and there is no constraint.
As more vehicles begin to charge and demand on the town centre supply increases, the DNO’s local controller detects that it is approaching its threshold.
To counteract this, the local controller instructs the high street charging hub to reduce its power consumption.
As vehicles finish charging, the local controller recognises that demand on the town centre supply has reduced.
The local controller detects that the town centre’s overall demand has decreased sufficiently to release capacity back to the high street charging hub.
The local controller sends a signal to the high street hub’s chargepoints, which can now operate at maximum power.