STATCOM based voltage-frequency regulation for SEIG driven by an uncontrolled speed turbine

Islanding is a condition in which a microgrid or a portion of power grid, consisting of distributed generation (DG) sources, converter, and load, gets disconnected from the utility grid. Under this condition the DG sources in a microgrid must switch to a voltage control mode, in order to provide constant voltage to local loads. In grid connected mode, the microgrid works as current controller and injects power to the main grid, depending on the power generation and local load with suitable market policies. Providing constant voltage at a stable frequency with proper synchronization amongst each DG in a microgrid is a challenge. The complexity of such grid requires careful study and analysis before actual implementation. These challenges of microgrid are addressed using real time OPAL-RT simulation technology. Thus the paper describes an islanded microgrid with master slave controller for power balance, voltage/frequency regulation, and synchronization. Based on an advanced real-time platform named Real-Time Laboratory (RT-LAB), the impacts of the micro sources, load, and converters in an islanded microgrid is studied in this paper. The effectiveness of the proposed controller is analyzed through experimental results under balanced/unbalanced nonlinear loads condition.

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Design of Networked Microgrid’s Control towards Power Coordination and Voltage - Frequency Regulation

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.d8908.049420 ◽

2020 ◽

Vol 9 (4) ◽

pp. 1693-1702

Keyword(s):

Power Sharing ◽

Energy Resources ◽

Frequency Regulation ◽

Renewable Energy Resources ◽

The Arts ◽

Variable Nature ◽

Flexible Integration ◽

Voltage Frequency ◽

Smart Grid System ◽

Inverter Topology

One of the state-of-the-arts of smart grid system is the concept of networked microgrid that provides flexible integration and coordination of distributed renewable energy resources in multiple microgrids. However, due to the variable nature of renewable generations, load changes and grid contingencies, the system suffers from significant fluctuations of power, voltage and frequency. This paper seeks to present comprehensive converter control solutions for power sharing coordination and stabilization of voltages and frequency to ensure high power quality and reliability in a networked microgrid system regardless of its grid-connected and islanded modes of operation. The control solutions are provided in d-q axes for both active and reactive powers. The multilevel inverter topology that is designed to interface the distributed energy resources results in better suppression of output harmonics compared to that with a conventional 2-level inverter. The paper also features an interlinking algorithm framework of particle swarm optimization (PSO) to tune the control parameters for the optimized performance of converters. A prototype of grid-connected system of three microgrids is simulated in PSCAD platform to validate the efficacy of the proposed solution.

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Optimal Voltage–Frequency Regulation in Distributed Sustainable Energy-Based Hybrid Microgrids with Integrated Resource Planning

Energies ◽

10.3390/en14102735 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2735

Author(s):

Amar Kumar Barik ◽

Dulal Chandra Das ◽

Abdul Latif ◽

S. M. Suhail Hussain ◽

Taha Selim Ustun

Keyword(s):

Solar Wind ◽

Sustainable Energy ◽

Resource Planning ◽

Frequency Regulation ◽

Load Variations ◽

Selfish Herd ◽

Opposition Based Learning ◽

Integrated Resource Planning ◽

Voltage Frequency ◽

Virtual Inertia

This work is the earliest attempt to propose an integrated resource planning for distributed hybrid microgrids considering virtual-inertia support (VIS) and demand-response support (DRS) systems. Initially, three-distributed sustainable energy-based unequal hybrid microgrids are envisioned with the availability of solar/wind/bioenergy resources. In order to overcome the effects of intermittency in renewable resources and low inertia, each microgrid is incorporated with DRS and VIS units for demand- and supply-side management, respectively. The proposed system is simulated in MATLAB considering real-time recorded solar/wind data with realistic loading for 12 months. A novel quasi-oppositional chaotic selfish-herd optimization (QCSHO) algorithm is proposed by hybridizing quasi-opposition-based learning and chaotic linear search techniques into the selfish-herd optimization, for optimal regulation of voltage and frequency in microgrids. Then, the system responses are compared with 7 algorithms and 5 error functions to tune PID controllers’ gains, which confirmed the superiority of QCSHO over others. Then, the study proceeds to investigate the voltage, frequency, and tie-line power coordination in 5 extreme scenarios of source and load variations in the proposed system without retuning the controllers. Finally, the system responses are analyzed for 10 different possible allocation of VIS and DRS units in different microgrids to find the most suitable combinations, and the results are recorded.

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