delSRPS 50662:2016

Zahtevi

Requirements for power frequency measurement for distributed energy resources (DER) to be connected to electrical energy supply systems

Апстракт

The deliverable defines minimum requirements on the measurement of the power frequency for DER to be connected to in electrical energy supply networks for the self-regulating control of generating plants as well as loads in the case of power frequency deviations. Characteristics to be developed are:
a) Framework conditions for measurement and analysis
Recommended combinations of admissible measurement duration and required accuracy are given for different kind of use cases at least the P-by-f droop (LFSM) and control strategies using the rate of change of frequency (ROCOF), see e.g. CLC TS 50549-1 and TS 50549-2. These comprise cases with high accuracy (and certain measurement duration) as well as cases with a focus on fast reaction (and lower accuracy):
- Maximum permissible duration of a measurement & analysis interval;
- Minimum accuracy of the measurement & analysis;
- Ranges for the response characteristic (step response) of the measuring & analysis element.

The scope also comprises requirements for the derivative of the measuring element’s output. The properties of the rate of change of frequency (df/dt) determine the performance of sophisticated protection systems and the emulation of system inertia.
b) Immunity requirements
Requirements for the immunity of the measurement & analysis procedures have to be developed against electromagnetic disturbances which typically prevail in distribution networks more often than at transmission level, for example (sub)harmonics, vector jumps, flicker and voltage displacements after switching operations, etc. The correct functioning of measurement & analysis shall also be ensured outside operational security limits according to future Network Code Operational Security.
c) Testing requirements
Test procedures shall be developed to verify the correct response of measurement & analysis in a reproducible manner. The required accuracy has to be proved and an immunity assessment in an electromagnetically noisy environment is needed.