Showing items 1 - 7 of 7

Dynamic derivative-droop control for supercapacitor synthetic inertial support

- Akram, Umer, Mithulananthan, N., Shah, Rakibuzzaman, Islam, Rabiul

  • Authors: Akram, Umer , Mithulananthan, N. , Shah, Rakibuzzaman , Islam, Rabiul
  • Date: 2020
  • Type: Text , Conference proceedings , Conference paper
  • Relation: 2020 IEEE Industry Applications Society Annual Meeting, IAS 2020 Vol. 2020-January
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  • Description: Energy storage is recognized as a potential solution to alleviate the impacts of inertia reduction and intermittency due to the integration of inverter based renewable energy sources (RES) in power systems. Out of various rapid responsive energy storage technologies, supercapacitor energy storage (SCES) is the most promising technology for synthetic inertia support. Because the SCES has high power density, very small response time, and large cycle life. In this paper, a dynamic derivative-droop control strategy is developed for SCES to provide the synthetic inertia in low inertia power system. The proposed strategy overcomes the limitations of separately applied derivative and droop controls. In addition, the use of time varying gains (referred as dynamic) instead of fixed gains improves the performance compared to derivative-droop coordinated control. Different types of events are created at different penetration levels of RES to test the robustness of the proposed control. A comparison, based on RoCoF and frequency nadir, between the derivative, droop, derivative-droop coordinated and the proposed controls is presented to show the effectiveness of the proposed control approach. © 2020 IEEE.

Energy storage for short-term frequency stability enhancement in low-inertia power systems

- Akram, Umer, Mithulananthan, N., Shah, Rakibuzzaman, Basit, Saad

  • Authors: Akram, Umer , Mithulananthan, N. , Shah, Rakibuzzaman , Basit, Saad
  • Date: 2020
  • Type: Text , Conference paper
  • Relation: 2020 Australasian Universities Power Engineering Conference, AUPEC 2020
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  • Description: Power systems with large scale integration of inverter interfaced generation plants become vulnerable to short term frequency instability. The short term frequency stability is related to limiting the RoCoF and frequency nadir within acceptable standards following a contingency. Failure to limit frequency nadir and RoCoF can result in the activation of RoCoF relays and under frequency load shedding relays, leading to generation disconnection and unintentional load shedding. This can result in blackout. In this work energy storage system (ESS) is deployed in the two-area power system for improvement of short term frequency stability. A capacity optimization algorithm and dispatch scheme are developed for the ESS. The capacity estimation algorithm determines the required capacity of ESS. The proposed algorithm estimates the required capacity of energy storage while considering the complete dynamics of conventional generators, wind turbine, and power conversion systems. The dispatch scheme operates the ESS to inject the real power in the system to improve the short term frequency stability. The proposed methodology is verified in PSCAD. Simulation results depict the effectiveness of the proposed approach. © 2020 University of Tasmania.

Examination of effective VAr with respect to dynamic voltage stability in renewable rich power grids

- Alzahrani, Saeed, Shah, Rakibuzzaman, Mithulananthan, N.

  • Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, N.
  • Date: 2021
  • Type: Text , Journal article
  • Relation: IEEE Access Vol. 9, no. (2021), p. 75494-75508
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  • Description: High penetrations of inverter-based renewable resources (IBRs) diminish the resilience that traditional power systems had due to constant research and developments for many years. In particular, dynamic voltage stability becomes one of the major concerns for transmission system operators due to the limited capabilities of IBRs (i.e., voltage and frequency regulation). A heavily loaded renewable-rich network is susceptible to fault-induced delayed voltage recovery (FIDVR) due to insufficient effective reactive power (E-VAr) in power grids. Hence, it is crucial to thoroughly scrutinize each VAr resources' participation in E-VAr under various operating conditions. Moreover, it is essential to investigate the influence of E-VAr on system post-fault performance. The E-VAr investigation would help in determining the optimal location and sizing of grid-connected IBRs and allow more renewable energy integration. Furthermore, it would enrich decision-making about adopting additional grid support devices. In this paper, a comprehensive assessment framework is utilized to assess the E-VAr of a power system with a large-scale photovoltaic power. Plant under different realistic operating conditions. Several indices quantifying the contribution of VAr resources and load bus voltage recovery assists to explore the transient response and voltage trajectories. The recovery indices help have a better understanding of the factors affecting E-VAr. The proposed framework has been tested in the New England (IEEE 39 bus system) through simulation by DIgSILENT Power Factory. © 2013 IEEE.

Exploring the Dynamic Voltage Signature of Renewable Rich Weak Power System

- Alzahrani, S., Shah, Rakibuzzaman, Mithulananthan, N.

  • Authors: Alzahrani, S. , Shah, Rakibuzzaman , Mithulananthan, N.
  • Date: 2020
  • Type: Text , Journal article
  • Relation: IEEE Access Vol. 8, no. (2020), p. 216529-216542
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  • Description: Large-scale renewable energy-based power plants are becoming attractive technically and economically for generation mix around the world. Nevertheless, network operation has significantly changed due to the rapid integration of renewable energy in supply side. The integration of more renewable resources, especially inverter-based generation, deteriorates power system resilience to disturbances and substantially affects stable operations. The dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs) due to the limited capabilities of inverter-based resources (IBRs). A heavily loaded and stressed renewable rich grid is susceptible to fault-induced delayed voltage recovery. Hence, it is crucial to examine the system response upon disturbances, to understand the voltage signature, to determine the optimal location and sizing of grid-connected IBRs. Moreover, the IBRs fault contribution mechanism investigation is essential in adopting additional grid support devices, control coordination, and the selection of appropriate corrective control schemes. This article utilizes a comprehensive assessment framework to assess power systems' dynamic voltage signature with large-scale PV under different realistic operating conditions. Several indices quantifying load bus voltage recovery have been used to explore the system' s steady-state, transient response, and voltage trajectories. The recovery indices help extricate the signature and influence of IBRs. The proposed framework's applicability is carried out on the New England IEEE-39 bus test system using the DIgSILENT platform. © 2013 IEEE.

Forced oscillation in power systems with converter controlled-based resources- a survey with case studies

- Surinkaew, Tossaporn, Emami, Koanoush, Shah, Rakibuzzaman, Islam, Syed, Mithulananthan, N.

  • Authors: Surinkaew, Tossaporn , Emami, Koanoush , Shah, Rakibuzzaman , Islam, Syed , Mithulananthan, N.
  • Date: 2021
  • Type: Text , Journal article
  • Relation: IEEE Access Vol. 9, no. (2021), p. 150911-150924
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  • Description: In future power systems, conventional synchronous generators will be replaced by converter controlled-based generations (CCGs), i.e., wind and solar generations, and battery energy storage systems. Thus, the paradigm shift in power systems will lead to the inferior system strength and inertia scarcity. Therefore, the problems of forced oscillation (FO) will emerge with new features of the CCGs. The state-of-the-art review in this paper emphasizes previous strategies for FO detection, source identification, and mitigation. Moreover, the effect of FO is investigated in a power system with CCGs. In its conclusion, this paper also highlights important findings and provides suggestions for subsequent research in this important topic of future power systems. © 2013 IEEE.

Improving synthetic inertial response of supercapacitor using supplementary control signal

- Akram, U., Mithulananthan, N., Shah, R.

  • Authors: Akram, U. , Mithulananthan, N. , Shah, R.
  • Date: 2019
  • Type: Text , Conference paper
  • Relation: 9th International Conference on Power and Energy Systems, ICPES 2019, Perth, 10-12 December 2019
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  • Description: Power systems with high penetration of inverter-based renewable generation units result in reduced inertia. In such power systems, the frequency events due to plant outage or large sudden increase/decrease in load power cause an increased rate of change of frequency (RoCoF) and larger frequency deviations. The higher RoCoF and larger frequency nadir can cause frequency instability which leads to blackout. Energy storage units may be deployed in such systems to support the frequency response. In this paper, Supercapacitor (SC) energy storage is used to provide the inertial response in power system with high penetration of intermittent renewable energy sources. Derivative control is employed for inertia emulation of SC. An additional control input signal based on the frequency deviation is added to improve the inertial response. The robustness of the proposed control is tested with different penetration levels of renewable generation. A comparison between the derivative control and the proposed control is presented to show the effectiveness of the proposed scheme. © 2019 IEEE.

Sizing HESS as inertial and primary frequency reserve in low inertia power system

- Akram, Umer, Mithulananthan, N., Shah, Rakibuzzaman, Pourmousavi, S. Ali

  • Authors: Akram, Umer , Mithulananthan, N. , Shah, Rakibuzzaman , Pourmousavi, S. Ali
  • Date: 2021
  • Type: Text , Journal article
  • Relation: IET renewable power generation Vol. 15, no. 1 (2021), p. 99-113
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  • Description: Energy storage systems are recognised as the potential solution to alleviate the impacts of reduced inertia and intermittency in power systems due to the integration of renewable energy sources. Several energy storage technologies are available in the market with diverse power and energy characteristics, operational limitations, and costs. Besides, frequency regulations in power systems have different requirements, for example, inertial response requires high power for a short period while primary frequency regulation requires steady power for a longer time. Thus, it is crucial to find out the optimum sizes and types of storage technologies for these services. In this paper, a methodology for sizing fast responsive energy storage technologies for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation is developed. The sizing of storage systems for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation is done separately. The sizing of storage for inertial response is done in two steps. A region reduction iterative algorithm is proposed to estimate the storage size for inertial response. The sizing of the storage system for primary frequency regulation is done analytically. The sizing methodology incorporates the frequency dynamics of storage, converters, and other associated controls that affect the frequency response. Moreover, an economic analysis is carried out to find the optimum combination of storage technologies for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation services. The accuracy of the proposed sizing method has been compared with the metaheuristic algorithm based technique. The effectiveness of the proposed method is also compared with those in the literature. Simulation results show that the proposed method outperforms the existing methods in the literature. Finally, the non‐linear simulations revealed the validity of the optimal solutions.
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