A new global index for short term voltage stability assessment
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Alzahrani, Saeed
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Access Vol. 9, no. (2021), p. 36114-36124
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- Description: The utility scale of non-conventional generators (NCGs), such as wind and photovoltaic (PV) plants, are competitive alternatives to synchronous machines (SMs) for power generation. Higher penetration of NCGs has been respondent of causing several recent incidents leading up to voltage collapse in power systems due to the distinct characteristics of NCGs under different operating conditions. Consequently, the so-called system strength has been reduced with higher NCGs penetration. A number of indices have been developed to quantify system strength from the short-term voltage stability (STVS) perspective. None of the indices capture the overall performances of power systems on dynamic voltage recovery. In this paper, an improvement in one of the STVS indices namely, the Voltage Recovery Index (VRI), is proposed to overcome shortcomings in the original index. Moreover, the improved index is globalized to establish a new index defined as system voltage recovery index (VRIsys) to quantify STVS at the system level. The amended VRI and developed VRIsys are used in systematic simulations to quantify the impact and interaction of various factors that could affect system strength. The assessment was conducted using time-domain simulation with direct connected induction motors (DCIMs) and a proliferation of converter-based technologies on both the generation and load sides, namely, NCGs and Variable Speed Drives (VSDs), respectively. © 2013 IEEE.
Dynamic voltage signature of large scale PV enriched streesed power system
- Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Sode-Yome, Arthit
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 275-280
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- Description: Renewable power generations including flexible demand and energy storage systems leverage significant changes in network operation. Thereby, power systems with high renewable penetration manifest deteriorated resilience to disturbances. Hence, the stable operation of the system could be affected. With a paradigm shift, dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs). Predicting the dynamic voltage signature for the transmission system with high penetration of renewables is essential to assist in selecting appropriate corrective control. This paper utilized a comprehensive assessment framework to identify the dynamic voltage signature of the power system with PV and various loads. The voltage recovery index has been chosen as the quantifiable index to extricate the dynamic voltage signature. The applicability of the proposed framework is discussed using simulation studies on the IEEE-39 bus test system. © 2020 IEEE.
Dynamic voltage stability of unbalanced distribution system with high penetration of single-phase PV units
- Authors: Islam, Monirul , Mithulananthan, Nadarajah , Hossain, Jahangir , Shah, Rakibuzzaman
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of engineering (Stevenage, England) Vol. 2019, no. 17 (2019), p. 4074-4080
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- Description: Dynamic voltage instability (DVI) issues are the primary concern in low-voltage distribution network (DN) due to growing integration of low-inertia compressor motor loads such as air-conditioner and refrigerator. The concern of DVI is likely to increase owing to high penetration of rooftop type single-phase photovoltaic (PV) units in DN. On the other hand, DNs are inherently unbalanced as a result of load and line characteristics along with unbalanced PV penetration. This paper examines the impact of imbalance on the dynamic voltage stability (DVS) in DN and provides solutions to mitigate any adverse effects. Dynamic models of the single-phase PV units are developed and utilised in the paper. The degree of unbalanced is defined first, and then its impact on the DVS is investigated. From the investigation, it is observed that degree of instability is increased with the increment of imbalance. The paper has also proposed a mitigation strategy i.e. reactive power injection by PV inverter. Case studies are conducted on modified IEEE 4 bus system which represents a low-voltage DN. Results reveal that reactive power injection by PV inverter can improve the DVS by mitigating the impact of unbalance.
Impact of PV plant and load models on system strength and voltage recovery of power systems
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 263-268
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- Description: In recent years, non-conventional inverter-based sources, namely, wind, PV, and others have emerged as excellent alternatives to the traditional synchronous machine for power generation. It has also been reported that the so-called system strength may be reduced with high penetration of non-conventional generations (NCGs). A number of methods have been used to assess system strength which may not reflect the interdependency or reciprocal influence of various factors affecting it. This paper presents a thorough assessment to quantify the implications of and the interaction of various factors affecting system strength, with the voltage recovery index being used as a quantification tool. © 2020 IEEE.
Impact of Active Current Ramping of Large-Scale PV Plant on the Dynamic Voltage Stability
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah
- Date: 2021
- Type: Text , Conference paper
- Relation: 2021 IEEE PES Innovative Smart Grid Technologies - Asia, ISGT Asia 2021, Brisbane, 5-8 December 2021
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- Description: This paper investigates the impact of active current ramping rate (rrpwr) of Large-Scale photovoltaic (LSPV) plants on the short-term dynamic voltage stability. Thus, the rrpwr is adapted according to the fault distance from the LSPV plant Point of Integration (POI). The investigation shows that when a fault occurs closer to POI, lower rrpwr helps to achieve better voltage recovery. Lower rrpwr means slower active power recovery following active power curtailment activated by a grid fault. Therefore, lower rrpwr will not compromise the reactive power injection as needed. Based on the minimal improvement in the voltage recovery at POI, it can be concluded that the adaptive rrpwr is not an influential factor to improve the short-term dynamic voltage stability. © 2021 IEEE
Multi-mode damping control approach for the optimal resilience of renewable-rich power systems
- Authors: Setiadi, Herlambang , Mithulananthan, Nadarajah , Shah, Rakibuzzaman , Islam, Md Rabiul , Fekih, Afer , Krismanto, Awan , Abdillah, Muhammad
- Date: 2022
- Type: Text , Journal article
- Relation: Energies Vol. 15, no. 9 (2022), p.
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- Description: The integration of power-electronics-based power plants is developing significantly due to the proliferation of renewable energy sources. Although this type of power plant could positively affect society in terms of clean and sustainable energy, it also brings adverse effects, especially with the stability of the power system. The lack of inertia and different dynamic characteristics are the main issues associated with power-electronics-based power plants that could affect the oscillatory behaviour of the power system. Hence, it is important to design a comprehensive damping controller to damp oscillations due to the integration of a power-electronics-based power plant. This paper proposes a damping method for enhancing the oscillatory stability performance of power systems with high penetration of renewable energy systems. A resilient wide-area multimodal controller is proposed and used in conjunction with a battery energy storage system (BESS) to enhance the damping of critical modes. The proposed control also addresses resiliency issues associated with control signals and controllers. The optimal tuning of the control parameters for this proposed controller is challenging. Hence, the firefly algorithm was considered to be the optimisation method to design the wide-area multimodal controllers for BESS, wind, and photovoltaic (PV) systems. The performance of the proposed approach was assessed using a modified version of the Java Indonesian power system under various operating conditions. Both eigenvalue analysis and time-domain simulations are considered in the analysis. A comparison with other well-known metaheuristic methods was also carried out to show the proposed method’s efficacy. Obtained results confirmed the superior performance of the proposed approach in enhancing the small-signal stability of renewable-rich power systems. They also revealed that the proposed multimodal controller could enhance the penetration of renewable energy sources in the Javan power system by up to 50%. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Effects of non-stationary forced oscillation on electromechanical modes
- Authors: Surinkaew, Tossaporn , Emami, Kianoush , Shah, Rakibuzzaman , Mithulananthan, Nadarajah
- Date: 2021
- Type: Text , Conference paper
- Relation: 2021 IEEE PES Innovative Smart Grid Technologies - Asia, ISGT Asia 2021, Brisbane, 5-8 December 2021, 2021 IEEE PES Innovative Smart Grid Technologies - Asia, ISGT Asia 2021
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- Description: The forced oscillation (FO) containing variable frequencies, known as non-stationary FO, has yet been well understood in power system engineers. This paper analyzes the effects of the non-stationary FO on electromechanical modes (EMs) in the range of 0.2 to 2.0 Hz. The non-stationary forced disturbance (FD) with such variable frequency bands is mathematically modeled. The injection of the non-stationary FD results in the non-stationary FO. A modified subspace-based state-space identification (so-called 4SID) method is applied to estimate the non-stationary frequencies and damping ratios of the EMs along with a moving window. Effects of the non-stationary FO on the EMs are compared to those of the conventional FO. Simulation results are verified in the future 14-machine Southeast Australian power system with converter controlled-based generations under various FO conditions. © 2021 IEEE
Dynamic VAr planning of large-scale PV enriched grid
- Authors: Alzahrani, Saeed , Mithulananthan, Nadarajah , Alshareef, Abdulrhman , Shah, Rakibuzzaman
- Date: 2021
- Type: Text , Conference paper
- Relation: 2021 IEEE PES Innovative Smart Grid Technologies - Asia, ISGT Asia 2021, Brisbane, 5-8 December 2021
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- Description: The integration of more inverter-based renewable resources (IBRs) would make the grid susceptible to large disturbances. Short term voltage instability is one of the key concerns for the renewable rich power system. An additional dynamic VAr support would be desirable to enhance system recovery. STATCOM is technically and financially promising solution which can provide dynamic Var support to the renewable rich power system. In this paper, system transient performance is assessed after synchronous generators (SGs) being significantly replaced by IBRs. To avoid the delayed recovery, STATCOM was integrated at the point of common coupling (PCC). Considering the changes in the grid's effective VAr, a framework was proposed to size the STATCOM. Moreover, the influence of distributed STATCOM on system performance was also examined. The proposed framework has been tested in the New England 39 bus system through simulation by DIgSILENT Power Factory. © 2021 IEEE
Modelling and experimental assessment of high-frequency oscillation in DC microgrid
- Authors: Habibullah, Mohammad , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Islam, Syed , Islam, Rabiul
- Date: 2022
- Type: Text , Conference paper
- Relation: 2022 IEEE Global Conference on Computing, Power and Communication Technologies, GlobConPT 2022, New Delhi, India, 23-25 September 2022, 2022 IEEE Global Conference on Computing, Power and Communication Technologies (GlobConPT)
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- Description: A comprehensive analytical simulation and experimental assessment of the DC microgrid (DCMG) under various disturbances are presented in this paper. The investigation shows that the disturbances can cause a significant impact, i.e., voltage deterioration and power oscillation at the common DC bus. The DC-link capacitance is identified as a critical parameter for power oscillation regulation on the DC bus. Furthermore, the experimental study reveals the adverse effect of the electromagnetic interference filter on the DC grid, which is usually employed to limit the oscillation in the DC grid. Furthermore, it should be worth noting that a single variable controller is not sufficient to handle significant or moderate disturbances. This paper's findings could be considered a guideline for a DC microgrid design. © 2022 IEEE.
Dynamic signature-based alignment factor for Var allocation
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Akram, Umer , Krimanto, Uji
- Date: 2022
- Type: Text , Conference paper
- Relation: 14th IEEE PES Asia-Pacific Power and Energy Engineering Conference, APPEEC 2022, Melbourne, Australia, 20-23 November 2022, Asia-Pacific Power and Energy Engineering Conference, APPEEC Vol. 2022-November
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- Description: A driven-data trajectory approach has been developed to allocate dynamic VAr source (DVS) to improve the short-term voltage stability (STVS) of power grids. The siting approach for DVS would be carried out by the comparing grid responses of different sites with DVS by considering the desired reference response. The undergoing assessment emphatically covers the full signature of grid dynamics interaction involving generation, transmission, and load characteristics. For illustration, the developed approach is applied to the Reliability and Voltage Stability (RVS) test system designed for STVS analysis. Several scenarios are tested, such as different levels of induction motor load, large-scale PV (LSPV), and LSPV reactive current injection, to demonstrate the viability and robustness of the approach. Subsequently, the viability and robustness of the siting approach are verified by checking STVS performance using the VRIsys index. © 2022 IEEE.
Small-signal stability and resonance perspectives in microgrid : a review
- Authors: Krismanto, Awan , Mithulananthan, Nadarajah , Shah, Rakibuzzaman , Setiadi, Herlambang , Islam, Md Rabiul
- Date: 2023
- Type: Text , Journal article , Review
- Relation: Energies Vol. 16, no. 3 (2023), p.
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- Description: The microgrid (MG) system is a controlled and supervised power system consisting of renewable energy (RE)-based distributed generation (DG) units, loads, and energy storage. The MG can be operated autonomously or while connected to the grid. Higher intermittencies and uncertainties can be observed in MGs compared to the conventional power system, which is the possible source of small-signal stability in MG systems. It can be seen as disturbances around the stable operating point, which potentially lead to the small-signal instability problem within MGs. Small-signal instability issues also emerge due to the lack of damping torque in the MG. The integration of power electronic devices and complex control algorithms within MGs introduces novel challenges in terms of small-signal stability and possible resonances. The occurrence of interaction in a low- or no-inertia system might worsen the stability margin, leading to undamped oscillatory instability. The interaction within the MG is characterized by various frequency ranges, from low-frequency subsynchronous oscillation to high-frequency ranges around the harmonic frequencies. This study presents an overview of the dynamic model, possible sources of small-signal instability problems, and resonance phenomena in MGs. The developed models of MG, including structure, converter-based power generation, and load and control algorithms, are briefly summarized to provide the context of MG system dynamics. A comprehensive critical review of the previous research, including small-signal stability and resonance phenomenon for MGs, is also provided. Finally, key future research areas are recommended. © 2023 by the authors.
Investigation of oscillation and resonance in the renewable integrated DC-microgrid
- Authors: Habibullah, Mohammad , Mithulananthan, Nadarajah , Shah, Rakibuzzaman , Islam, Md Radiul , Muyeen, S.
- Date: 2023
- Type: Text , Journal article
- Relation: Electronics (Switzerland) Vol. 12, no. 7 (2023), p.
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- Description: This paper assessed the small-signal stability performance of a multi-converter-based direct current microgrid (DCMG). The oscillation and potential interactions between critical modes are evaluated. First, the complete analytical model of the DCMG is developed with the converter and associated controllers. Three methodologies, impedance scanning, eigenvalue analysis, and time-domain simulation, along with the fast Fourier transform (FFT) analysis, have been used to comprehensively investigate the oscillations and interactions. The simulation results show inherent weak modes, with a wide range of oscillations in the studied DCMG, which may destabilize the system under disturbances. Based on the sensitivity analysis, controller gains and DC-link capacitance are identified as the most critical parameters and substantially influence the weak modes leading to oscillations, interactions, and resonance. Finally, the performance of the various control synthesis methods is compared. This examination would help the researchers, planning, and design engineers to design and stably operate a multi converter-based DC microgrid. © 2023 by the authors.
A unified damping controller for non-stationary forced oscillation
- Authors: Surinkaew, Tossaporn , Emami, Kianoush , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Muyeen, S. , Fernando, Tyrone
- Date: 2022
- Type: Text , Journal article
- Relation: International Journal of Electrical Power and Energy Systems Vol. 143, no. (2022), p.
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- Description: Forced disturbances (FDs) with non-stationary frequencies can sequentially resonate from electromechanical modes (EMs) to sub/super synchronous modes (SSMs) and thus lead to non-stationary forced oscillations (FOs). Previous FO damping controllers designed for specified frequency bands may not be able to suppress the non-stationary FOs. This paper proposes a unified FO damping controller design method to deal with all oscillations caused by non-stationary FOs. The model of a power system with non-stationary FOs is obtained by a continuous model detection and identification of measured signals, which does not require any value of the system parameters. Accordingly, four stability indices, i.e., robustness, interaction, frequency, and damping ratio of the EMs and SSMs, can be calculated from the estimated model. At each operating point, these indices are monitored and used to optimally design the unified FO damping controller. The effectiveness of the proposed unified FO damping controller is verified in the modified Southeast Australian power system with converter controlled-based generations under various operating points and FO conditions. © 2022 Elsevier Ltd