The introduction of microgrids in distribution networks based on power electronics facilitates the use of renewable energy resources, distributed generation (DG) and storage systems while improving the quality of electric power and reducing losses thus increasing the performance and reliability of the electrical system. The hierarchical control structure, which consists of primary, secondary, and tertiary levels for microgrids that mimic the behavior of the mains grid, is reviewed. The main objective of this article is to give a description of state of the art for distributed power generation systems (DPGS) based on renewable energy and explore the power converters connected in parallel to the grid which are distinguished by their contribution to the formation of the grid voltage and frequency and are accordingly classified in three classes. This analysis is extended focusing mainly on the three classes of configurations: grid-forming, grid-feeding, and grid-supporting. The article ends up with an overview and a discussion of the control structures and strategies to control distribution power generation system (DPGS) units connected to the network.

/pdf/a-survey-on-control-of-electric-power-distributed-generation-16eexny94f.pdf

A Survey on Control of Electric Power Distributed Generation Systems for Microgrid Applications

This paper focuses on a comparative study of the modeling and simulation of the first CIGRE HVDC benchmark system using two simulation tools PSCAD/EMTDC and PSB/SIMULINK; an interface between them (PSCAD-SIMULINK) has also been implemented and used as a simulator. The CIGRE HVDC system and its controller has been carefully modeled in all three simulation environments so that the differences are minimal. Comparison of steady-state and transient situations have been carried out, and a high degree of agreement in most of the cases has been observed.

Detailed modeling of CIGRE HVDC benchmark system using PSCAD/EMTDC and PSB/SIMULINK

Covering the fundamentals of electrical transients, this book should equip readers with the skills to recognise and solve transient problems in power networks and components. Starting with the basics of transient electrical circuit theory, and moving on to discuss the effects of power transience in all types of power equipment, it provides insight into this important field. Recent advances in measurement techniques, computer modelling and switchgear development are given comprehensive coverage for the first time. An electromagnetic transients calculation program is included and should prove valuable to both students and engineers in the field.

https://bib.convdocs.org/v10706/?download=1

Transients in Power Systems

Isolated renewable energy systems based on hybrid wind-solar sources are considered as feasible and reliable options instead of wind-diesel systems. An isolated hybrid scheme employing a simple three-phase square-wave inverter to integrate a photovoltaic array with a wind-driven induction generator has been proposed for the first time. A dynamic mathematical model of the hybrid scheme with variables expressed in d-q synchronous reference frame has been developed. The model is implemented in the power system blockset platform and a comparison has been made between transients simulated and transients obtained in an experimental prototype. Close agreement between experimental and the simulated waveforms has been observed, which validates the model.

A novel hybrid isolated generating system based on PV fed inverter-assisted wind-driven induction Generators

This paper presents the development of a unique parallel and distributed real-time digital simulator for power engineering research at the University of Alberta. The simulator is built entirely from commodity-off-the-shelf (COTS) hardware and software components, making it very flexible and scalable. In parallel multi-tasking operations, a combination of real-time Linux operating system and an ultra-fast network forms the backbone for the internal communication between the 16 powerful processors of the Xeon-Cluster. Field programmable gate array (FPGA)-based multi-channel digital and analog I/O ports are interfaced to communicate with the external hardware components. The model development software utilized for power applications is based on the highly customizable industry-standard MATLAB/SIMULINK environment. A detailed case study of the real-time simulation of a three-level 12-pulse vector-controlled ac drive is presented to illustrate the precision capabilities of the simulator. Multiple integration algorithms and multirate computation have been applied for the simulation of the system, with slow (machine) and fast (converter) dynamic components. Real-time simulation of the entire system has been achieved with a maximum computation time of 5.35 /spl mu/s on a step-size of 10 /spl mu/s for the first time. Results obtained from the real-time simulation have been validated with an offline simulation using PSCAD/EMTDC.

A versatile cluster-based real-time digital simulator for power engineering research

This paper describes the Power System Blockset (PSB) from The MathWorks, Natick, MA, which is a new software package for the simulation of electric circuits, power systems, power electronic devices, and electric drives. The PSB is developed in the graphical Simulink environment of the general-purpose Matlab software. This blockset inherits a number of advantages from its development environment, namely, an open architecture, a powerful graphical user interface, and versatile analysis and graphics tools. The user can integrate control systems implemented with Simulink blocks directly into a diagram built with the PSB. Solution of differential equations is accomplished using the state-space approach with variable-step variable-order integration algorithms. A simulation example is presented, and the results are compared with those obtained with PSPICE.

A power system simulation tool based on Simulink

This paper presents a unified framework for power system simulation using a Simulink environment. The modeling and simulation of power systems under Simulink are described and discussed. Application examples for power systems including power networks, power electronics and electric machines are presented and compared with two popular simulation packages (EMTP, PSpice).

Theory and applications of power system blockset, a MATLAB/Simulink-based simulation tool for power systems

Hysteresis modeling in the MATLAB/power system blockset

This paper presents a study on an interpolation algorithm capable of handling multiple switching during one time step in fixed time step simulation of pulse-width modulated (PWM) power converters. The proposed algorithm is analyzed and implemented in Simulink's SimPowerSystems simulation engine. Simulation results obtained with a test system consisting of a variable-speed wind-turbine-driven permanent-magnet synchronous generator are presented. The algorithm is evaluated by comparing the obtained results with those produced by a small time step simulation.

Analysis and Implementation of an Interpolation Algorithm for Fixed Time-Step Digital Simulation of PWM Converters

This paper describes a powerful new simulation tool aimed at helping engineers design electric drives. The proposed drives library contains models for the most popular AC and DC drives found in industrial applications, and also contains mechanical coupling models used to connect mechanical load models to the drive models. The library's open architecture enables users to use each model as is or customize it to suit specific needs. After describing the models included in the library, usability enhancing characteristics of the tool are discussed and a case study Is presented to demonstrate the tool's abilities.

P. Brunelle

Papers

A power system simulation tool based on Simulink

Theory and applications of power system blockset, a MATLAB/Simulink-based simulation tool for power systems

Hysteresis modeling in the MATLAB/power system blockset

Analysis and Implementation of an Interpolation Algorithm for Fixed Time-Step Digital Simulation of PWM Converters

A new simulation tool for the design of systems with electric drives