Course code Ener4003

Credit points 2

Electric Power Supply and Tariffs

Total Hours in Course32

Number of hours for lectures16

Number of hours for seminars and practical classes16

Date of course confirmation16.03.2011

Responsible UnitInstitute of Energetics

Course developer

author Enerģētikas institūts

Indulis Straume

Mg. sc. ing.

Prior knowledge

ETeh2019, Applied Electrical Engineering

ETeh4037, Fundamentals of Electrical Engineering I

ETeh4048, Fundamentals of Electrical Engineering II

Fizi1009, Basic Physics

Fizi2032, Physics I

Fizi2033, Physics II

Mate2035, Mathematics IV

Course abstract

Basic concepts of electric energy supply for agricultural, internal and external electric nets design and calculations, voltage regulation principles, current of short connected circuit calculations, overvoltage and protection from it are covered during studies. Electric energy supply systems and equipments, safety of electric supply is studied. Tariff system, saving and rational usage of energy, technical and economical characteristics of energy equipment are analyzed as well.

Learning outcomes and their assessment

Knowledge: the design of electricity supply systems and the parameters of the transmission lines, the reliability of power supply and the construction and use of hardware - test 1 and 2.
Abilities: to perform engineering calculations for elements of the power supply systems and to choose the element parameters - 1-3 home works.
Competencies: choose the parameters and equipment of the power supply system that meet the requirements of the consumer, assess their performance, justify electricity tariffs, their application to energy objects - home work, examination.

Course plan

1. Electricity supply grids, consumers, electricity quality.
2. Elements of the supply line - wires, cables, supports, insulators. Wire and cable parameters.
3. Network transformers - structure, cooling systems.
4. Distribution, and their equipment - circuit breakers, disconnectors, overvoltage arresters.
5. Neutral operating modes.
6. Power and power losses, their calculations, and loss prevention methods.
7. Voltage losses and their calculation.
Test 1. Introduction to the structure of electricity supply, elements and equipment of power transmission networks, neutron operating modes, voltage, power and power losses.
8. Selection of wire cross-sectional area: economic considerations.
9. Selection of wire cross-sectional area: after permissible voltage drop.
10. Heating of the wires and their selection at the acceptable temperature.
11. Fuses and circuit breakers. Selectivity
12. Distribution of power supply system’s according to the type of grounding and their contours.
13. Overvoltage types and surge protection equipment.
14. Tariffs and factors affecting them.
Test 2. Wire cross-section calculation methods, grounding and overvoltage protection devices, and tariffs.

Requirements for awarding credit points

A written exam.
Four questions in the exam.
All home works must have been completed and tests credited.

Description of the organization and tasks of students’ independent work

1st home work. Calculation of the cross-sectional area of the wire, taking into account one cross-sectional area for the entire line.

2st home work. Calculating the cross-sectional area of the wiring, taking into account the economy of the conductor material.

3st home work. Choice of weld cross section for branched electrical grid.

Criteria for Evaluating Learning Outcomes

The assessment of the study course exam depends on the cumulative assessment of the exam assignment and the study course test papers and homework.
A test or an exam is passed if at least 50% of the test questions are answered correctly.
The homework assignment is evaluated in accordance with the assessment procedure specified in the assignments of homework.
The exam mark is calculated as the arithmetic mean of the exam assignments and the average semester mark, which is calculated as the arithmetic mean of the marks of tests and homework taken from the study course.

Compulsory reading

1. Vanags A. Elektriskie tīkli un sistēmas. I daļa. Rīga: RTU, 2007. 479 lpp. 2. Vanags A., Krišāns Z. Elektriskie tīkli un sistēmas. II daļa. Rīga: RTU, 2005. 342 lpp.

Further reading

1. Overvoltage protection. OBO Bettermann GMBH&CO katalogs. 122 p. 2. Руководство по решению задач по курсу Электроснабжение. Мockвa: МЭИ, 1998. 85 с. 3. Sabiedrisko pakalpojumu regulēšanas komisijas (SPRK) ar padomes 2003.gada 29.janvāra lēmumu Nr.34 apstiprināta “Elektroenerģijas realizācijas gala tarifa aprēķina metodika”. Rīga, 2003. 10 lpp.