Control Design and Parameter Tuning for Islanded Microgrids by Combining Different Optimization Algorithms (original) (raw)
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Optimal Control of Islanded Micro grid Using Particle Swarm Optimization Algorithm
International Journal of Industrial Electronics, Control and Optimization (IECO), 2018
Microgrid is defined as a controllable unit which consists of Distributed Generations (DG), loads, energy storages and control devices. Microgrid has two operation modes including grid connected mode and islanding mode. In grid connected mode, voltage and frequency of microgrid is controlled by main grid and DG’s supply total or part of the loads. In the islanding mode, the microgrid is disconnected from main grid because of a fault or a preplanned switching in connecting line. In this mode, DG’s should satisfy the power demand of sensitive loads in microgrid. Since the only generation units in an islanded microgrid are existing DG units which usually are from several types. Consequently besides feeding total loads, voltage and frequency of microgrid should be controlled by these DG units. Hence, the microgrid could supply high power quality and reliability to customers. This paper presents an optimization method to optimize the parameters of the Microgrid controller in islanding mode. The controller optimal parameters have been obtained by using the particle swarm optimization (PSO). This is done based on minimization of the error in the current and voltage controllers. Finally, simulation has been carried out to verify the effectiveness of the optimized controller. Stability analysis of the controller is verified using classical approach.
IEEE Access
An efficient power control technique for inverter-based distributed generation (DG) in an islanded microgrid is investigated in this work. The objective is to raise the caliber of the electricity pumped from network-connected DGs. The characteristics that are taken into consideration include voltage and frequency control, dynamic response, and steady-state response, particularly when the microgrid is operating in island mode or when there is a load change. The control method consists of an internal current control loop and an external power control loop based on a synchronous reference frame and a conventional PI controller. The power controller is designed based on voltage-frequency (VF) control. In addition, an intelligent search technique that combines Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) is utilized to automatically modify power controller parameters. The control technique in this research is that the DG modifies its control mode to modify the system voltage and frequency when the microgrid is islanded or load conditions change. The simulation results in MATLAB/SIMULINK software show that the proposed control system has been able to improve the power quality well.
European Transactions on Electrical Power, 2011
Microgrids are state-of-the-art power distribution networks consisting of multiple distributed generators (DGs) and sensitive power loads. The goal of microgrid operation is to provide reliable and high-quality electric power to loads regardless of abnormal cases such as faults or loss-of-mains (islanding). This paper presents power control methods to coordinate multiple microgrid generators for both grid-connected and autonomous modes. To maintain required control performance and power quality during operating condition changes, hard toil of fine-tuning control parameters is required. This paper proposes an effective control parameter-tuning method using the particle swarm optimization (PSO) algorithm and gain-scheduling method. System requirements such as power quality regulation and load following performance are reflected in the cost function. The optimization algorithm implementation with time-domain simulation model is also explained.
Stability analysis of an autonomous microgrid operation based on Particle Swarm Optimization
2012 IEEE International Conference on Power System Technology (POWERCON), 2012
This paper presents the stability analysis for an in verter based Distributed Generation (DG) unit in an autonomous microgrid operation. The small-signal model of the controlled Voltage Source Inverter (VSI) system is developed in order to investigate the dynamic stability for the given operating point and under the proposed power controller. This model includes all the details of the proposed controller, while no switching actions are considered. System oscillatory modes and the sensitivity to the control parameters are the main performance indices which are considered, particularly when the micro grid is islanded or under the load change condition. In this work, the proposed power controller is composed of an inner current control loop and an outer power control loop, both based on a synchronous reference frame and conventional PI regulators. These controllers also utilize the Particle Swarm Optimization (PSO) for real-time self-tuning in order to improve the quality of the power supply. The complete small-signal model is linearized and used to define the system state matrix which is employed for eigenvalue analysis. The results prove that the stability analysis is fairly accurate and the controller offers reliable system's operation.
Processes, 2019
The islanded mode of the microgrid (MG) operation faces more power quality challenges as compared to grid-tied mode. Unlike the grid-tied MG operation, where the voltage magnitude and frequency of the power system are regulated by the utility grid, islanded mode does not share any connection with the utility grid. Hence, a proper control architecture of islanded MG is essential to control the voltage and frequency, including the power quality and optimal transient response during different operating conditions. Therefore, this study proposes an intelligent and robust controller for islanded MG, which can accomplish the above-mentioned tasks with the optimal transient response and power quality. The proposed controller utilizes the droop control in addition to the back to back proportional plus integral (PI) regulator-based voltage and current controllers in order to accomplish the mentioned control objectives efficiently. Furthermore, the intelligence of the one of the most modern s...
New Control Method of Islanded Microgrid System: A GA & ICA based optimization approach
Modares Journal of Electrical Engineering, 2016
Microgrids are small-scale, low voltage (LV) power networks which employ renewable distribution energy resources (DERs) with power electronic interfaces (PEIs). Microgrids as single controlled units and active distribution networks require flexible control systems to ensure reliable and secure operation in different modes. These various operations of microgrid cause variations in voltage and frequency especially in island mode. In this paper, a new control method with two optimization algorithms (genetic algorithm (GA) & imperialist competitive algorithm (ICA)) are proposed to eliminate both voltage and frequency disturbances. Also, a new concept of conventional droop control in format of fast droop controller (FDC) is designed to guaranty the microgrid system reliability with cooperation of a modern frequency controller. Simulation results show the truth behavior of proposed approach in comparison with previous methods.
Power quality improvement in autonomous microgrid operation using particle swarm optimization
2011 IEEE PES Innovative Smart Grid Technologies, 2011
This paper presents an optimal power control strategy for an autonomous microgrid operation based on a realtime self-tuning method. The purpose of this work is to improve the quality of power supply where Distributed Generation (DG) units are connected to the grid. Dynamic response and harmonics distortion are the two main performance parameters which are considered in this work, particularly when the microgrid is islanded. The controller scheme is composed of an inner current control loop and an outer power control loop based on a synchronous reference frame and the conventional PI regulators. Particle Swarm Optimization (PSO) is an intelligent searching algorithm that is applied for real-time self-tuning of the system. The results show that the proposed controller provides an excellent dynamic response with acceptable harmonics level.
Sustainability, 2021
This article studied the load frequency control (LFC) of a multi-source microgrid with the presence of renewable energy sources. To maintain a sustainable power supply, the frequency of the system must be kept constant. A Proportional–Integral–Derivative (PID) controller is presented as a secondary controller to control the frequency of the microgrid in island mode, and the integral of squared time multiplied by error squared (ISTES) is used as a performance index. The use of the Craziness-Based Particle Swarm Optimization (CRPSO), which is an improved version of Particle Swarm Optimization (PSO), improves the convergence speed in optimizing the nonlinear problem of load and frequency controller design. The test microgrid is composed of the load and distributed generation units such as diesel generators, photovoltaics and wind turbines. The proposed controller provided the desired response to adjusting the microgrid frequency, achieving the final response after a short time and maki...
2021
The voltage deviation challenge associated with Islanded microgrid system terminal voltage usually impacts negatively on the stability of the Islanded microgrid. This occurs as a result of load variation conditions and the intermittency nature of distributed generation (DG) in the Islanded MG. To curtail this effect and ensure the stability of the system for power quality improvement, an optimal voltage control technique can be employed to minimize this drawback on Islanded microgrid operations. This study utilized the Sine Cosine algorithm (SCA) to optimize the control gains of the PI controller for voltage deviation minimization in an Islanded microgrid. The SCA technique was implemented on modelled Islanded microgrid with two parallelconnected inverters. Stability analysis was carried out on the Islanded microgrid and voltage deviation, overshoot, settling time, and rise time was used as performance metrics. The simulation results that emerged from the MATLAB/Simulink are compared to the PSO technique established in the literature. The results reveal that the SCA optimized PI controller has achieved a voltage overshoot improvement of 21.6%. The results indicate that SCA optimized PI controller outperformed the PSO reported in the literature.
Journal of Control Engineering and Applied Informatics, 2016
The control of distributed generations (DGs) with renewable resources is an important endeavor in modern power systems due to the fact that the system frequency and voltages are highly variable in these kinds of networks especially in the island mode. This paper introduces a new combination of conventional controllers for solving the critical problems in islanded microgrid systems. With considering the -phase operation of power networks and comfort controllability of the system, the general controller is designed based on two mentioned techniques. The indicator of proper performance of studied microgrid controller is to provide reliable electric power in the presence of the transmission line impact and abnormal conditions. The control system parameters are optimized by Imperialist competitive algorithm (ICA) for enhancing the power quality. The effectiveness of recommended method is contrasted with other controllers and studies. The simulation results show the truth behavior of sug...