Common use of REACTIVE POWER SERVICE Clause in Contracts

REACTIVE POWER SERVICE. The Reactive Power service relates to the reactive power generated or absorbed by the participating DER plant. This production/absorption of reactive power could allow more effective control of the voltage in the transmission system. The Reactive service is initiated by the DERMS issuing instructions to DER at the start of each Service Window for which DER was contracted, to change its operating mode (where necessary): for a non-synchronous contracted DER unit, to operate in voltage droop control mode; or for a synchronous contracted DER unit, to operate in voltage control mode When in these control modes, DER will automatically respond to voltage changes measured at the DER Connection Point. In addition to this, a National Grid instruction via the DERMS would translate into a change of DER voltage set-point to achieve National Grid’s request. In either case, the response would be achieved within 2-5 seconds, as per service requirements. Otherwise, the DER would be kept operating at their default operating level and the DERMS would adjust DER voltage set-points if needed to keep a unit’s reactive power output as close to its default value as possible.