Droop Control Strategy of Utility-Scale Photovoltaic Systems Using Adaptive Dead Band

This paper proposes a novel droop control strategy for addressing the voltage problem against disturbance in a transmission system connected with a utility-scale photovoltaic. Typically, a voltage control at the renewable energy sources (RESs) connected to the transmission grid uses a reactive power–voltage control scheme with a fixed dead band. However, this may cause some problems; thus, this paper proposes a method for setting a dead band value that varies with time. Here, a method for calculating an appropriate dead band that satisfies the voltage maintenance standard for two disturbances is described using voltage sensitivity analysis and the equation of existing droop control. Simulation studies are conducted using the PSS® E program to analyze the short term voltage stability and display the results for various dead bands. The proposed modeling and operational strategy are validated in simulation using a modified IEEE 39 bus system. The results provide useful information, indicating that the control scheme through an adaptive dead band enables more stable system operation than that through a fixed dead band.

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Frequency and Voltage Supports by Battery-Fed Smart Inverters in Mixed-Inertia Microgrids

Electronics ◽

10.3390/electronics9111755 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1755 ◽

Cited By ~ 1

Author(s):

Mohsen S. Pilehvar ◽

Behrooz Mirafzal

Keyword(s):

Power Generation ◽

Reactive Power ◽

Piecewise Linear ◽

Renewable Energy Sources ◽

Storage System ◽

Energy Storage System ◽

Droop Control ◽

Control Scheme ◽

Islanded Microgrid ◽

Frequency Fluctuations

This paper presents a piecewise linear-elliptic (PLE) droop control scheme to improve the dynamic behavior of islanded microgrids. Islanded microgrids are typically vulnerable to voltage and frequency fluctuations, particularly if a combination of high- and low-inertia power generation units are used in a microgrid. The intermittent nature of renewable energy sources can cause sudden power mismatches, and thus, voltage and frequency fluctuations. The proposed PLE droop control scheme can be employed in a battery energy storage system (BESS) to effectively mitigate voltage and frequency fluctuations in an islanded microgrid. Though the PLE shape can be implemented for any droop control scheme, it has been applied for active power-frequency (P-f) and reactive power-voltage (Q-v) droops in this paper. In addition, the dynamic response of a battery-fed smart inverter equipped with the proposed PLE droops has been compared with the results obtained from a linear droop control scheme in an islanded microgrid containing high- and low-inertia power-generation units. In this paper, the results of several case studies are presented to confirm the capability of the PLE droop control in mitigating voltage and frequency fluctuations in islanded microgrids.

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A Novel Approach Using Adaptive Neuro Fuzzy Based Droop Control Standalone Microgrid In Presences of Multiple Sources

International Journal of Renewable Energy Development ◽

10.14710/ijred.9.1.43-51 ◽

2019 ◽

Vol 9 (1) ◽

pp. 43-51

Author(s):

Srinivas Singirikonda ◽

Y.P. Obulesu

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Voltage Control ◽

Synchronous Generator ◽

Droop Control ◽

Renewable Generation ◽

Generation System ◽

Voltage Control Strategy ◽

Neuro Fuzzy ◽

Micro Grid

In this paper, a novel Q/P droop control strategy for regulating the voltage and frequency in Standalone micro grid with multiple renewable sources like solar and wind is presented. The frequency and voltage control strategy is applied to a Standalone micro grid with high penetration of intermittent renewable generation system. Adaptive Neuro-Fuzzy logic Interface system (ANFIS) controller is used for frequency and voltage control for Renewable generation system. Battery energy storage system (BESS) is used to generate nominal system frequency instead of using the synchronous generator for frequency control strategy. A synchronous generator is used to maintain the state of charge (SOC) of the BESS, but it has limited capacity. For Voltage control strategy, we proposed reactive power/active power (Q/P) droop control to the conventional reactive power controller which provides voltage damping effect. The induced voltage fluctuations are reduced to get nominal output power. The proposed model is tested on different cases and results show that the proposed method is capable of compensating voltage and frequency variations occurring in the micro grid with minimal rated synchronous generator. ©2020. CBIORE-IJRED. All rights reserved

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The reactive power voltage control strategy of PV systems in low-voltage string lines

2017 IEEE Manchester PowerTech ◽

10.1109/ptc.2017.7980995 ◽

2017 ◽

Cited By ~ 1

Author(s):

Feng Zhang ◽

Xiaolong Guo ◽

Xiqiang Chang ◽

Guowei Fan ◽

Lianger Chen ◽

...

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Low Voltage ◽

Voltage Control ◽

Voltage Control Strategy ◽

Pv Systems

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A Novel Hierarchical Control Strategy for Low-Voltage Islanded Microgrids Based on the Concept of Cyber Physical System

Energies ◽

10.3390/en11071835 ◽

2018 ◽

Vol 11 (7) ◽

pp. 1835 ◽

Cited By ~ 1

Author(s):

Qiuxia Yang ◽

Dongmei Yuan ◽

Xiaoqiang Guo ◽

Bo Zhang ◽

Cheng Zhi

Keyword(s):

Control Strategy ◽

Physical System ◽

Reactive Power ◽

Low Voltage ◽

Hierarchical Control ◽

Physical Layer ◽

Cyber Physical System ◽

Droop Control ◽

Control Effect ◽

Consensus Control

Based on the concept of cyber physical system (CPS), a novel hierarchical control strategy for islanded microgrids is proposed in this paper. The control structure consists of physical and cyber layers. It’s used to improve the control effect on the output voltages and frequency by droop control of distributed energy resources (DERs), share the reactive power among DERs more reasonably and solve the problem of circumfluence in microgrids. The specific designs are as follows: to improve the control effect on voltages and frequency of DERs, an event-trigger mechanism is designed in the physical layer. When the trigger conditions in the mechanism aren’t met, only the droop control (i.e., primary control) is used in the controlled system. Otherwise, a virtual leader-following consensus control method is used in the cyber layer to accomplish the secondary control on DERs; to share the reactive power reasonably, a method of double virtual impedance is designed in the physical layer to adjust the output reactive power of DERs; to suppress circumfluence, a method combined with consensus control without leader and sliding mode control (SMC) is used in the cyber layer. Finally, the effectiveness of the proposed hierarchical control strategy is confirmed by simulation results.

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An Advanced Droop Control Strategy for Reactive Power: Assessment in Islanded Microgrids

IEEE Transactions on Power Systems ◽

10.1109/tpwrs.2021.3124062 ◽

2021 ◽

pp. 1-1

Author(s):

Manuela Minetti ◽

Alessandro Rosini ◽

Gio Battista Denegri ◽

Andrea Bonfiglio ◽

Renato Procopio

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Droop Control

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An Improved Droop Control Strategy for Reactive Power Sharing in Islanded Microgrid

IEEE Transactions on Power Electronics ◽

10.1109/tpel.2014.2332181 ◽

2015 ◽

Vol 30 (6) ◽

pp. 3133-3141 ◽

Cited By ~ 142

Author(s):

Hua Han ◽

Yao Liu ◽

Yao Sun ◽

Mei Su ◽

Josep M. Guerrero

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Power Sharing ◽

Droop Control ◽

Islanded Microgrid

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Constant DC-Capacitor Voltage-Control-Based Reactive Power Control Strategy of Three-Level NPC Inverter-Based STATCOM

2018 21st International Conference on Electrical Machines and Systems (ICEMS) ◽

10.23919/icems.2018.8549401 ◽

2018 ◽

Author(s):

Ayumu Tokiwa ◽

Toshihiko Tanaka ◽

Yukiharu Satake ◽

Mitsunori Fukuda ◽

Hiroaki Yamada

Keyword(s):

Power Control ◽

Control Strategy ◽

Reactive Power ◽

Voltage Control ◽

Reactive Power Control ◽

Capacitor Voltage

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Heuristic Coordinated Voltage Control Schemes in Distribution Network with Distributed Generations

Energies ◽

10.3390/en13112849 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2849

Author(s):

Seok-Il Go ◽

Sang-Yun Yun ◽

Seon-Ju Ahn ◽

Hyun-Woo Kim ◽

Joon-Ho Choi

Keyword(s):

Power Control ◽

Reactive Power ◽

Voltage Control ◽

Distribution Networks ◽

Control Voltage ◽

Reactive Power Control ◽

Distributed Generations ◽

Control Scheme ◽

Control Devices ◽

Node Voltage

The voltage and reactive power control (Volt/VAR Control, VVC) in distribution networks has become a challenging issue with the increasing utilization of distributed generations (DGs). In this paper, a heuristic-based coordinated voltage control scheme that considers distribution voltage control devices, i.e., on-load tap changers (OLTC) and step voltage regulators (SVR), as well as reactive power control devices, i.e., DGs, are proposed. Conventional voltage control methods using non-linear node voltage equations require complex computation. In this paper, the formulation of simplified node voltage equations accounting for changes in tap position of distribution voltage control devices and reactive power changes of reactive power control devices are presented. A heuristic coordinated voltage control scheme using the proposed simplified node voltage equations is proposed. A coordinated voltage control scheme to achieve voltage control for nominal voltage and conservative voltage reduction (CVR) is presented. The results of the proposed schemes are compared with the results from the quadratic optimization method to confirm that the proposed schemes yields suitably similar results. Furthermore, a tap scheduling method is proposed to reduce the number of tap changes while controlling network voltage. The tap position is readjusted using a voltage control performance index (PI). Simulation results confirm that when using this method the number of tap changes is reduced. The proposed scheme not only produces reasonable performance in terms of control voltage of networks but also reduces the number of tap changes made by OLTC. The proposed control method is an alternative candidate for a system to be applied to practical distribution networks due to its simplified calculations and robust performance.

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Reactive Power Optimal Control of a Wind Farm for Minimizing Collector System Losses

Energies ◽

10.3390/en11113177 ◽

2018 ◽

Vol 11 (11) ◽

pp. 3177 ◽

Cited By ~ 5

Author(s):

Yunqi Xiao ◽

Yi Wang ◽

Yanping Sun

Keyword(s):

Large Scale ◽

Wind Farm ◽

Energy Savings ◽

Reactive Power ◽

Voltage Control ◽

Wind Farms ◽

Voltage Sensitivity ◽

Voltage Control Strategy ◽

Power Sources ◽

Collector System

A reactive power/voltage control strategy is proposed that uses wind turbines as distributed reactive power sources to optimize the power flow in large-scale wind farms and reduce the overall losses of the collector system. A mathematical model of loss optimization for the wind farm collector systems is proposed based on a reactive power/voltage sensitivity analysis; a genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are used to validate the optimization performances. The simulation model is established based on a large-scale wind farm. The results of multiple scenarios show that the proposed strategy is superior to the traditional methods with regard to the reactive power/voltage control of the wind farm and the loss reduction of the collector system. Furthermore, the advantages in terms of annual energy savings and environmental protection are also estimated.

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