System Non-Synchronous Penetration Definition and Formulation

Transcription

1 System Nn-Synchrnus Penetratin Definitin and Frmulatin Operatinal Plicy 27 August 2018

2 Disclaimer EirGrid as the Transmissin System Operatr (TSO) fr Ireland, and SONI as the TSO fr Nrthern Ireland make n warranties r representatins f any kind with respect t the infrmatin cntained in this dcument. We accept n liability fr any lss r damage arising frm the use f this dcument r any reliance n the infrmatin it cntains. Use f this dcument and the infrmatin it cntains is at the user s sle risk. System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 2

3 Intrductin With increasing level f installed nn-synchrnus generatin capacity i.e. wind and slar, and further intercnnectin t the All-Island pwer system, it is necessary t measure and limit the System Nn-Synchrnus Penetratin () t ensure safe and prudent peratin f the system. The purpse f this dcument is t clarify the definitin f. The definitin f is based n the results f the Facilitatin f Renewables (FR) studies. If future studies shw a change in the definitin is required, this plicy will be updated accrdingly. Cntext The FR studies identified a number f issues assciated with perating the pwer system with high penetratins f nn-synchrnus surces (e.g. wind generatin and intercnnectr imprts). These issues include frequency stability, transient stability and vltage stability, fllwing the lss f a large infeed r fllwing a transmissin fault. The metric was develped, based n analysis f the results f the studies, t prvide a single cnstraint that captures the range f issues. Althugh the metric is an apprximatin, it is deemed a prudent cnstraint t apply in real-time peratin. In the FR studies, intercnnectr imprt cases and exprt cases were cnsidered but wheeling flws (imprt n ne intercnnectr and exprt n the ther) were nt explicitly studied. Nevertheless, fr the current level f intercnnectin, it is believed that wheeling flws will nt materially impact n system security. Therefre intercnnectr flws are netted prir t use in the calculatin. This may be reviewed in future as further intercnnectrs cnnect t the system. System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 3

4 System Nn-Synchrnus Penetratin Definitin is a measure f the nn-synchrnus generatin n the system at an instant in time. It is the rati f the real-time MW cntributin frm nn-synchrnus generatin and net HVDC imprts t demand plus net HVDC exprts. The equatin t express as a percentage is thus frmulated as fllws: Where: (%) = Nn Synchrnus Generatin + Net Intercnnectr Imprts Demand + Net Intercnnectr Exprts x 100 Nn-Synchrnus Generatin = Ttal Large Scale Nn-Synchrnus Generatin + Representatin f Ttal Small Scale Nn-Synchrnus Generatin Ttal Large Scale Nn-Synchrnus Generatin = Ttal wind and PV generatin n the All-Island system (and all additinal nn-synchrnus generatin, e.g. tidal) Representatin f Ttal Small Scale Nn-Synchrnus Generatin is calculated as fllws: SSG Rep = (Installed Capacity f Small Scale Wind Generatin * Rati f Availability t Installed Capacity f Large Scale Wind Generatin * 0.6) + (Installed Capacity f Small Scale PV Generatin * Rati f Availability t Installed Capacity f Large Scale PV Generatin) Net Intercnnectr Imprts/Exprts = The net flw f Myle and EWIC, where flws are measured at the SEM end i.e. Myle MW flw is measured at Ballycrnan Mre and EWIC MW flw is measured at Prtan (e.g. at full exprt EWIC is 530 MW) Demand is measured in generated 1 terms and fr the purpses f includes Turlugh Hill pump demand. It is calculated as fllws fr real-time calculatins: Demand = All-Island System Generatin (including nn-synchrnus generatin) + Net Imprts Net Exprts Where All-Island System Generatin 2 represents the generatin required t meet the System Demand and any Turlugh Hill pump demand 1 Generated Pwer = Exprted Pwer + Generatr Huse Lad 2 This is an All-Island equivalent f the current EMS System Generatin. Fr example, if the demand was 3,000MW and there were tw pumps n lad at 73 MW each, the System Generatin wuld be apprx. 3,146MW. System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 4

5 Additinal Ntes: It is assumed that Turlugh Hill is regarded as additinal demand when pumping; Demand Side Units, when dispatched, result in an implicit reductin in Demand; and Aggregated Generating Units shuld be cnsidered additinal synchrnus generatin. System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 5

6 Settlement Implementatin DS3 System Services Scalars are applied t DS3 System Service tariffs in rder t incentivise flexibility, reliability, value fr mney and perfrmance in the prvisin f the services. The (%) metric, as described abve, is an input int the calculatin f the value f the Tempral Scarcity Scalar. The time-weighted average f the (%) value is calculated fr each 30-minute settlement trading perid. The Tempral Scarcity Scalar is then applied t the tariff f the services as described in Table 1. Table 1: Tempral Scarcity Scalar Values (effective May 1st 2018) System Service 0% - 50% Tempral Scarcity Scalar Values >50% & 60% >60% & 70% >70% & 75% POR SOR TOR TOR RRS RRD RM RM RM SIR SSRP FFR DRR FPFAPR The Tempral Scarcity Scalar is ne f a number f scalars applicable t the payment t Prviding Units fr the prvisin f DS3 System Services. A Prviding Unit s cntractual Scaling Factr fr the prvisin f a service is the prduct f the scalars applicable t that service. System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 6

7 Further infrmatin n DS3 System Services scalars can be fund in the SEM Cmmittee decisin paper n tariffs and scalars 3, and the TSOs scalar design recmmendatins paper fs%20and%20scalars%20final%20versin.pdf 4 DesignFinal_ pdf System Nn-Synchrnus Penetratin Operatinal Plicy August 2018 Page 7