## Modelling of Electrical Power Systems

Programme Summary

Major: 13.04.02 Power Industry and Electrical Engineering

Specialisation: Power Supply

Degree: Master

Course units:

Unit 1. Basics of modelling theory. The concept of model and classification

Unit 2. Modelling of complex electric power systems for ferrous metallurgy

Unit 3. Basics of modelling in Matlab by Mathworks with the Simulink and National Instruments Multisim applications

Unit 4. Math modelling of the electric loop of an electric arc furnace

Unit 5. Math modelling of the ‘Thyristor converter/Separately excited DC motor’ system

Unit 6. Math modelling of a static VAR compensator for non-linear and abruptly variable load (EAF and TC-M)

Unit 7. Modelling of high-voltage synchronous motor

Unit 8. Modelling of synchronous generator

Unit 9. Modelling of the ‘Frequency converter/AC motor’ system

Course contents:

Unit 1. Basics of modelling theory. The concept of model and classification.

The concept of modelling. Classification of models by presentation (full-scale, material or mathematical), by level of accuracy (complete, incomplete, approximate), by the time factor (static and dynamic). Mathematical modelling. Requirements to math models. Similarity and adequacy. The concept of experiment and classification.

Unit 2. Modelling of complex electric power systems for ferrous metallurgy

Complex power system. Types of power systems utilized at metallurgical sites (superpower electric arc furnaces with static VAR compensators, thyristor motor drives of hot and cold rolling mills, high-voltage synchronous motors of oxygen plants and the roughing stands of a hot mill, synchronous generators of in-house power plants; advanced high-power lines built with AC motors and frequency converters of various make) and their features. Purpose and problems of modelling of the above objects.

Unit 3. Basics of modelling in Matlab by Mathworks with the Simulink and National Instruments Multisim applications

Basics of Matlab by Mathworks (the graphic interface; basic operations with data; basics of the embedded programming language; basic Simulink libraries; dealing with the main blocks of the SimPowerSystem library; model calculation techniques; presentation of math modelling outcomes). Basics of National Instruments Multisim (the graphic interface; dealing with the main blocks of electrical elements; presentation of math modelling outcomes).

Unit 4. Math modelling of the electric loop of an electric arc furnace

Math modelling of the electric loop of an electric arc furnace (EAF). Simplified EAF model with the electric arc presented in the form of variable active resistance. Single-phase and three-phase EAF models with the electric arc presented in the form of back EMF. Single-phase and three-phase EAF models with the use of the Cassie arc equation. Comparison of the EAF electrical characteristics obtained with the above models. Assessment of the EAF current harmonic content. Assessment of the AEF impact on the supply mains through modeling.

Unit 5. Math modelling of the ‘Thyristor converter/Separately excited DC motor’ system

Modeling of back-EMF 6- and 12-pulse rectifiers with current control. Identification of key energy and electrical parameters of a thyristor converter, such as overlap angle, delay angle, average rectified current and voltage. Calculation of the higher current harmonics produced by a thyristor converter.

Unit 6. Math modelling of a static VAR compensator for non-linear and abruptly variable load (EAF and TC-M)

Math model of filter compensation networks. Obtaining the resulting frequency response of the supply mains and the higher harmonics filters. Math model of a thyristor-reactor group (TRG). Implementing a TRG control system. Studying the reactive power compensation for different modes of EAF and TC-M.

Unit 7. Modelling of high-voltage synchronous motor

Building a synchronous motor (SM) model based on the Park-Gorev equations. Matrix model of a synchronous motor. SM model built with the SimPowerSystem library blocks. Designing an automatic excitation controller to ensure a stable dynamic response of a SM in case of solid state load surges or main power dips etc. Exploring a SM in transition modes.

Unit 8. Modelling of synchronous generator

Building a synchronous generator (SG) model based on the Park-Gorev equations. Designing an automatic excitation controller. Exploring a SG in transition modes.

Unit 9. Modelling of the ‘Frequency converter/AC motor’ system

Math model of a frequency converter with a DC link. Math model of a converter with an active front end rectifier. Building AC motor u/f and vector control systems. Studying the pulse width modulation algorithms. Exploring the energy and power characteristics of a frequency converter.

Activities:

1. Teacher-led group activities in a classroom;
2. Extracurricular self-study of the teacher’s assignments and tasks, including the use of educational facilities (obligatory);
3. Office-hours.

Total hours – 108

Total points – 3

Classroom hours – 15

Unsupervised hours – 93

Midterm assessment – Pass/fail examination