Performance requirements modeling and assessment for active power ancillary services

Abstract

Abstract-New sources of ancillary services are expected in the power system. For large and conventional generation units the dynamic response is well understood and detailed individual measurement is feasible, which factors in to the straightforward performance requirements applied today. For secure power system operation, a reliable service delivery is required, yet it may not be appropriate to apply conventional performance requirements to new technologies and methods. The service performance requirements and assessment methods therefore need to be generalized and standardized in order to include future ancillary service sources. This paper develops a modeling method for ancillary services performance requirements, including performance and verification indices. The use of the modeling method and the indices is exemplified in two case studies.

Maximum ramp rate estimation for active powers from generation units

“…Here h is the sampling period. The upper (lower) limit ofr max, + can be calculated with the lower (upper) limit ofb and the lower (upper) limit ofâ in (27) according to (30). The (1 − α) × 100% confidence interval ofr max, + is…”

“…Lobato et al evaluated AGCS performance indices by comparing actual AGCS responses of generation units with desired behaviors from a reference model 26 . Bondy et al formulated some AGCS performance indices from the perspective of providing active power ancillary services to power grids 27 . Wang et al assessed AGCS performances of generation units in view of the consistency between variations of active powers and AGC commands 28 .…”

“…26 Bondy et al formulated some AGCS performance indices from the perspective of providing active power ancillary services to power grids. 27 Wang et al assessed AGCS performances of generation units in view of the consistency between variations of active powers and AGC commands. 28 Pathak et al modeled the ramp rate constraints of generation units to improve AGCS performance for power grids.…”

Redefining Requirements of Ancillary Services for Technology Agnostic Sources

“…The estimation of the service provision performance can be done in different ways, depending on which parameters the system operator deems to be the most critical. A service performance index is proposed in [16], where service performance is defined as the root mean square error of the actual service delivery compared to an ideal service model:…”

Optimal performance evaluation of thermal AGC units based on multi-dimensional feature analysis

“…Therefore, AGC instructions must be preprocessed in performance evaluation. In [36], a generic modeling method for quality of AGC service is proposed. The time series error between the unit output and the set-point power is defined, and the error is scaled accordingly for different economic rules.…”