On the virtual inertia provision by BESS in low inertia power systems

This paper emphasizes the importance of battery energy storage systems (BESS) for frequency stability in low inertia power systems. A mixed input signal is considered for the BESS control, consisting of the frequency variation and the rate of change of frequency, as a solution to deploy the BESS for providing both inertia and primary frequency control. A sensitivity analysis on the influence of each input signal and the reaction time of the BESS on the frequency control, as well as on the frequency stabilization was performed. Simulation are conducted on a two-area interconnected power system to study and validate the capability of BESS to provide virtual inertia and contribute to system frequency regulatio

Frequency Control Reserve With Multiple Micro Grid Participation For Power System Frequency Stability

The introduction of this micro grids into the conventional distribution network system forces a new challenge to the system operation. The failure factor of the power system performance essentially due to the limitation of electrical power generation in which could not meet the load demand. In order to maintain the frequency stability of the system, the power sources must be matched instantaneously among all generators and constantly supply to the load demand. A deviation of system frequency from the set-point value will affect the entire stability of power system network. This paper investigates the impact of utilizing multiple micro grids in supporting and facilitating on grid’s frequency. A method called Frequency Control Reserve (FCR) is introduced, with intention to share the excessive power from all available micro grids. These power will be controlled effectively before being injected into the main grid to stabilize the power frequency. Simulation using MATLAB Simulink have been used to simulate the result and shows great potential to be integrated with distributed generation i.e. solar photovoltaic (PV) for Malaysia power system vicinit

BESS Techno-economic challenges to support wind energy: Mind mapping and correlation matrix

This paper proposes a compact approach to perform a preliminary techno-economic feasibility study to decide the technology and size of Battery Energy Storage System (BESS) that is suitable to particular application(s). A detailed mind matrix is proposed to provide a high-level vision of the incorporated technoeconomic challenges and questions within the process, where 38 issues are expansively considered. Afterwards, a prioritization scheme is presented to evaluate the benefits and required capacity of BESS integration aiming to mitigate the complexity of such study. A simplified costing model is also discussed to highlight the main factors that judge the financial value of the BESS. This paper provides spotlight on the key knowledge gaps and research areas that could be of interest to industry and academic stakeholders

Future-oriented generic grid code regarding wind power plants in Europe

The assessment of compliance with grid codes requirements can be challenging for researchers and (early stage) technology developers. To tackle this problem, a generic grid code is proposed in this article that defines certain requirements aimed for future scenarios with high shares of renewables. The proposed code is not linked to a particular grid of a certain region or country. The requirements are expressed in a mathematical way, in contrast to the legal format of real grid codes, to enable for easier implementation. The parameterised expressions enable for easy customisation for specific use cases. The compliance is assessed through reference under/over voltage test events and a test frequency disturbance, to which desired responses are specified. Detailed dynamic tolerance bands are defined around the desired responses, using linear parameterised functions providing a clear and continuous definition that leaves little room for interpretation. This generic grid code is inspired by the present regulations, especially the European grid code framework (ENTSO-E RfG) and the Irish grid code, which is seen by many as a benchmark regarding wind power integration. However, the generic grid code includes additional requirements that are not commonly part of grid codes today, including requirements covering asymmetric faults and inertia-like response to frequency deviations.acceptedVersio

A Battery Energy Management Strategy for UK Enhanced Frequency Response and Triad Avoidance

This paper describes a control algorithm for a battery energy storage system (BESS) to deliver a charge/discharge power output in response to changes in the grid frequency constrained by the National Grid Electricity Transmission (NGET) - the primary electricity transmission network operator in the UK - whilst managing the state-of-charge (SOC) of the BESS to optimise the availability of the system. Furthermore, this paper investigates using the BESS in order to maximise Triad avoidance benefit revenues whilst layering other services. Simulation using a 2 MW/1 MWh lithium-titanate BESS validated model are carried out to explore possible scenarios using the proposed algorithms. Finally, experimental results of the 2MW/1MWh Willenhall Energy Storage System (WESS) verify the performance of the proposed algorithms

Modeling and Analysis of an LCC HVDC System Using DC Voltage Control to Improve Transient Response and Short-Term Power Transfer Capability

A new control method for a line-commutated converter-based (LCC) high-voltage direct-current (HVDC) system is presented and compared to a conventional strategy. In the proposed method, both the DC voltage and current of an LCC HVDC system are regulated to increase the short-term operating margin of DC power transfer and improve transient responses to DC power references. In particular, an increased operating margin of DC power transfer is achieved via the DC voltage regulation method. To verify the effectiveness of the proposed method, a state space model of an LCC HVDC system is developed considering DC voltage and current references as input variables and analyzed for various values of the DC line inductance and converter controller gains. The state space model can be used for time-efficient analyses of the dynamic characteristics of an LCC HVDC system. Simulation case studies are performed using MATLAB, where the state space model of the Jeju-Haenam HVDC system is implemented as a test case and compared to its comprehensive PSCAD model. The case study results suggest that the proposed method increases the short-term operating margin and speeds up the transient response of the HVDC system. Therefore, it will effectively improve real-time grid frequency regulation.11sciescopu

Integration of wind and solar energies with battery energy storage systems into 36-zone Great Britain power system for frequency regulation studies

Variable-speed wind generators (VSWGs) and solar Photovoltaic (PV) units are being broadly employed as the main renewable energy sources in large-scale transmission power networks. However, they can cause system stability challenges following power imbalances since they provide no inertial and governor responses. In this study, generic dynamic models are developed for VSWGs, PVs and battery energy storages systems (BESSs) which include inertia emulator and droop-based frequency control schemes. These models are suitable for transmission systems stability studies and are integrated into 36-zone Great Britain (GB) power system in DIgSILENT PowerFactory. It is a very useful benchmark for academic research and industrial sectors to undertake feasibility studies for renewable energy integration into GB power system. However, it is not an exact equivalent of the real GB power system. The dynamic time-domain simulations and modal analysis are provided and justified to investigate how PV, Wind and BESS units affect the system frequency response. A sensitivity analysis is also carried out against several factors to demonstrate the dynamic performance of the test system incorporating the generic models for VSWGs, PVs and BESSs. These are associated with units’ frequency response and system frequency changes under renewable energies’ penetration levels of 20 %, 25 %, 50 %, 60 % and 75 % of system demand.© 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed