Generation Units In Microgrid Research Articles

An Optimal Configuration Method for Microgrid Energy Storage Capacity via Combination of Empirical Modal Analysis and Convolutional Neural Network

This paper proposes a method that considers the bus net Fuzzy control strategy quickly and accurately for power. Due to the intermittent and fluctuating characteristics of distributed generation units in microgrid, the power quality will be reduced and the normal operation of microgrid will be affected. In this paper, empirical modal analysis fused with convolutional neural network algorithm is applied to the power control strategy of microgrid energy storage system to improve the economy and reliability of microgrid. The design process of the controller is analyzed, and fuzzy rules and membership functions are designed according to the effect requirements of the controller. Then, the center of gravity method is used to obtain the output power of the energy storage system. The simulation results show that the configuration scheme based on the optimization of the hybrid energy storage system in the whole life cycle in this paper not only ensures the stability of the energy storage system but also effectively avoids power fluctuations and stabilizes the peak shaving and valley filling rate. While improving the economy of the energy storage system, it also increases the service life of the energy storage system.

A Fully Resilient Cyber-Secure Synchronization Strategy for AC Microgrids

This letter focuses on resilient synchronization in networked ac microgrids under cyber-attacks, where attackers aim to desynchronize converters by injecting bounded false data to communication and control channels. To this end, a resilient cooperative control framework for the secondary frequency regulation in ac microgrids is developed. The proposed resilient distributed control strategy achieves synchronization regardless of the existence of cyber-attacks. Moreover, it offers the maximum level of resilience, i.e., it guarantees resilient synchronization even if all distributed generation units in microgrids are subject to cyber-attacks. Theoretical analysis and verification case studies are carried out in order to demonstrate the advantages and performance of the proposed resilient cooperative control.

An Active/Reactive Power Control Strategy for Renewable Generation Systems

The development of distributed generation, mainly based on renewable energies, requires the design of control strategies to allow the regulation of electrical variables, such as power, voltage (V), and frequency (f), and the coordination of multiple generation units in microgrids or islanded systems. This paper presents a strategy to control the active and reactive power flow in the Point of Common Connection (PCC) of a renewable generation system operating in islanded mode. Voltage Source Converters (VSCs) are connected between individual generation units and the PCC to control the voltage and frequency. The voltage and frequency reference values are obtained from the P–V and Q–f droop characteristics curves, where P and Q are the active and reactive power supplied to the load, respectively. Proportional–Integral (PI) controllers process the voltage and frequency errors and set the reference currents (in the dq frame) to be imposed by each VSC. Simulation results considering high-power solar and wind generation systems are presented to validate the proposed control strategy.

Online optimal stationary reference frame controller for inverter interfaced distributed generation in a microgrid system

This paper presents a novel optimal real-time controller for inverter-based distributed generation units in an islanded microgrid. With respect to the fact that the microgrid has a completely nonlinear structure and its dynamics is constantly changing, the linear controllers with constant and inflexible coefficients cannot maintain proper response in a wide range of operation conditions. Hence, an optimal nonlinear controller that theirs coefficient are adjusted in a real-time manner based on fuzzy logic is presented. To improve the performance of the proposed real-time controller, its fuzzy system parameters are determined using an offline particle swarm optimization algorithm for various operation conditions. In the proposed real-time controller, proportional-resonant controllers are used due to their advantage in the stationary reference frame for controlling the voltage and current of distributed generation units in the microgrid. Capability and efficiency of the proposed real-time controller are evaluated in different operation scenarios in MATLAB/Simulink environment. The simulation results shows that changing the control coefficients online with respect to operation condition leads to achievement of an optimum answer for voltage during the occurrence of islanding condition and also in case of load variation in the islanded microgrid.

Optimal scheduling of distributed energy resources in a distribution system based on imperialist competitive algorithm considering reliability worth

A model for energy trading in microgrids (MGs) is proposed in this paper. Imperialist competitive algorithm is used as a powerful method to determine the optimal schedule of all generation units in MG. The optimal scheduling is determined over a planning horizon considering all the constraints of the MG elements and the load demands. Scheduling of distributed generations (DGs) in the MG affects the risk of blackout in the power system. Therefore, a new objective function is presented to investigate the effect of DGs scheduling on the risk of partial or total blackout. DGs generate the great portion of energy in a MG. Generated power by some of DGs is strongly dependent on the weather and ambient conditions. Therefore, the power generation forecast is the major concern for constructing the model for MG energy trading. In this paper, artificial neural network (ANN) is used to predict hourly power outputs of DGs in the MG. Based on the ANN-based forecast module, the imperialist competitive algorithm is developed to determine the MG scheduling, by which the sources can be managed and an optimal operation can be achieved.