Investigation of Load Frequency Relief From Field Measurements and Its Impact on Contingency Reserve Evaluation

• Published in: IEEE transactions on power systems Vol. 33; no. 1; pp. 567 - 577
• Main Authors: Nahid-Al-Masood, Ruifeng Yan, Saha, Tapan Kumar
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2018
• Subjects: Australia; Contingency management; Frequency response; Generators; Induction motors; load frequency relief; Load modeling; Nanoelectromechanical systems; power system security; Reactive power
• ISSN: 0885-8950; 1558-0679
• DOI: 10.1109/TPWRS.2017.2707530

Any mismatch between load and generation (due to a generator or an interconnection trip) is intended to be balanced and stabilized by contingency reserve, which is also known as contingency Frequency Control Ancillary Services (FCAS) requirement. Load Frequency Relief (LFR), which represents the effect of frequency dependent loads on power system frequency excursion, is crucial for correctly evaluating contingency reserve requirement during generation dispatch to ensure an adequate frequency response. Over estimation of LFR can be accountable for less planned reserve during an economic dispatch that may cause undesirable frequency performance. On the other hand, under estimation of LFR can result in an excessive reserve and hence could unnecessarily increase system operational cost. Conventionally, LFR is considered as a fixed quantity during the evaluation of FCAS requirement. However, recent experience in the Australian power grid suggests that such an assumption may lead to an inaccurate outcome. To explore the above issue, this research investigates the LFR using field measurement data, which were captured at different locations of the southern states of Australia (e.g., Tasmania and Victoria). An approach is developed to identify the predominating factors affecting the LFR and subsequently a technique is proposed to appropriately determine contingency FCAS requirement.