Candidate: Sofia Guzman
Title: Fast Frequency Regulation in Power Systems with Energy Storage
Date: April 1, 2020
Time: 3:00 PM
Place: REMOTE PARTICIPATION
Supervisor(s): Canizares, Claudio - Bhattacharya, Kankar
Abstract:
Ancillary services, such as Frequency Regulation (FR), reactive power support and voltage control, certified black start facilities, among others, are key to ensure the reliable operation of a power system. The FR service corrects the power mismatch between generation and load, including the losses, and helps to correct frequency variations in the system. Traditionally, FR has been provided by synchronous generators with automatic regulation control capability. Considering that FR intends to correct the short-term power changes that might distress the stability of the power system, the fast response of the facilities contracted for FR is essential. However, traditional generators are limited by their time response and ramp rate, which means that fast changes in demand cannot be properly handled by these facilities. Energy Storage Systems (ESSs), such as batteries and flywheels, are able to respond in a period of a few seconds to a given signal. In recent years, there has been a significant interest in ESS technologies because of their decreasing cost. Hence, penetration of ESS technologies is likely to grow significantly in the coming years. Indeed, it is envisaged that services that have been traditionally procured from synchronous generators, such as FR, will also be provided by ESSs. However, appropriate frequency control techniques must be designed to take advantage of the fast response capability of ESS facilities, while coordinating their operation with the bulk conventional generators currently used for FR. Some characteristics of the bulk power grids, regulation signals, and the management of ESSs are relevant for the design of the frequency control model.
In this seminar, the effects of integrating ESSs facilities and a split regulation signal in the FR process of a large power system will be examined. Ontario’s power system is used as a case study, and the main stages of its FR control process are represented by an approximate model, which was validated using real data. This model includes communication delays, which must be considered due to their significant impact in the FR process. The scheduled FR signal is divided in two signals: one slow regulation signal (Reg A), and one fast regulation signal (Reg D). The Reg A signal is sent to the traditional generators, which are able to sustain their energy output for long periods, but have a slower time response. On the other hand, the Reg D signal is sent to the ESSs facilities, which are not able to sustain their energy output for long periods, but can modify their output very fast. Simulation results of the implementation of ESSs and a filter to divide the scheduled FR signal will be presented, and their impact in the FR control process will be discussed.