# A Comprehensive Approach to Evaluate Frequency Control Strength of Power Systems

## TL;DR

This paper introduces 'frequency control strength' as a new metric to compare power system robustness, revealing that larger capacity doesn't always mean better frequency control, with variations influenced by regulations and system configurations.

## Contribution

It proposes a novel measure for frequency control strength and provides a comprehensive comparison of real-world renewable-based power systems using this metric.

## Key findings

- AUS has the highest frequency control strength during normal conditions.
- AIPS shows the highest relative strength during abnormal conditions.
- Regulatory and system arrangements significantly influence frequency control strength.

## Abstract

This paper introduces the concept of "frequency control strength" as a novel approach to understand how different real-world power systems compare to each other in terms of effectiveness and performance of system-wide frequency control. It presents a comprehensive comparison, based on measurement data, of the frequency control strength of four real-world, renewable-based, synchronous islands power systems, namely Great Britain (GB), All-Island power system (AIPS) of Ireland, and Australia (AUS) mainland and Tasmania (TAS). The strength is evaluated by means of different frequency quality metrics. The common understanding is that the bigger the capacity of a power system, the bigger its robustness with respect to events and contingencies. Here we show that this is not always the case in the context of frequency control. In fact, our study shows that mainland AUS shows the highest frequency control strength during normal operating conditions, whereas the AIPS shows the highest relative frequency control strength for abnormal system conditions. The strength is, in particular, greatly influenced by different regulatory requirements and different system/ancillary services arrangements in each jurisdiction. The paper also provides possible mitigations to improve frequency control strength through grid codes and market rules.