Course detail

# Power Converter Design

FEKT-MNVMAcad. year: 2018/2019

Snubber circuits and soft switching technique for the switching transistors. DC supplying of the power converters. Electromagnetic compatibility (EMC). Magnetic phenomena in the power electronics. Optimal design of the chokes with the ferromagnetic core and the air gap, air coils and reactors. Transformers: mathematical models, equivalent circuit, substitute circuit. Voltage transformer. Current transformer. Power pulse transformers. Power converters with the pulse transformer (switch-mode supplies).

Current sensors. Rogowski belt.

Supervisor

Learning outcomes of the course unit

It is proved by written test, and oral exam that student is able:

- To reproduce the induction law in the differential and integral form. To define the linkage flux of the inductor.

- To define the discrete and linear magnetic circuit. To outline Hopkinson law. To determine the meaning of the permeability. To define all magnetic quantities, and to define the relations between its.

- To list the basic types and properties of ferromagnetic materials.

- To describe the net interference filters. To describe the current compensated choke. To define the capacitance interference currents in the system net - converter - motor.

- To design and to calculate the choke with the ferromagnetic core and the air gap.

- To define the equivalent circuit of the transformer. To measure the coupling coefficient and the mutual inductance.

- To analyse the voltage transformer. To determine the current and voltage transfer.

- To analyse the current transformer. To determine the low boundary frequency.

- To design and to calculate the net transformer.

- To describe the single-end buck converter with the transformer. To determine the time waves of the currents and voltages.

- To describe the doble-end buck converter with the transformer. To determine the time waves of the currents and voltages.

- To describe the single-end buck converter with the demagnetization into zener diode. To determine the time waves of the currents and voltages.

- To describe the single-end boost converter with the transformer. To determine the time waves of the currents and voltages.

- To describe the control circuits of the switch mode supply sources.

- To describe the DC current transducers with the Hall sensor.

- To describe the Rogowski belt.

In the laboratory practices the student measures and analyses signals in different power converters with help of oscilloscope. Student trains following skills:

- To handle and to use basic measure instruments in the power electronics laboratory: oscilloscope, voltmeter, ampermeter, DC and AC laboratory supplies.

- To set and to connect the work bench for the measuring of the switch mode supply sources.

- To measure the ocsillograms in the single-end buck converter with the transformer.

- To measure the ocsillograms in the double-end buck converter with the transformer.

In the numerical lectures the student learns following skills:

- To design and to calculate the choke with the ferromagnetic core and the air gap.

- To design and to calculate the power air choke.

- To design and to calculate the net transformer.

- To design and to calculate the single-end buck converter with the transformer.

- To design and to calculate the double-end buck converter with the transformer.

Prerequisites

Student must have the previous knowledge from the applied mathematics:
- To use and to apply the mathematical operations above complex numbers in the component and polar representation (summation, subtraction, multiplication, division, and rectification of the complex fraction).
- To apply the basic principles of the integral and differential calculus of one variable: description of the inductor work, i.e. induction law in the differential and integral form, similarly the dif. and integr. relation between instant values of the current and voltage at the capacitor. Calculus of the mean and RMS values of the periodical function.
Student must have the previous general knowledge and ability:
- To describe basic properties of the discrete electronic devices (diode, bipolar and unipolar transistor).
- To attend the course BREB (Control Electronics).
- To be able practically to use and to apply the following tools for the analysis and synthesis of the electric circuits: 1st and 2nd Kirchhoff laws, Ohm law, induction law in the differential and integral form.

Co-requisites

Not applicable.

Recommended optional programme components

Not applicable.

Recommended or required reading

Caha Z., Černý M.: Elektrické pohony. SNTL, 1990. (CS)

Chee-Mun Ong: Dynamic Simulation of Electric Machinery. Prentice-Hall, 1998. (EN)

Patočka M.: Vybrané statě z výkonové elektroniky, sv.I. (CS)

Patočka M.: Vybrané statě z výkonové elektroniky, sv.II. (CS)

Bose, B.K.: Power electronics and AC Drives. Prentice Hall 1986 (EN)

Planned learning activities and teaching methods

Lectures are lead with the massive support of Power-Point. The Power-Point file is available for students.

In laboratories, students measure 4 exercises (power converters) with the help of oscillograph.

In numerical exercises, the typical tasks are solved (design of power converters of all types).

Assesment methods and criteria linked to learning outcomes

Requirements for completion of a course are specified by a regulation issued by the lecturer responsible for the course and updated for every.

Language of instruction

Czech

Work placements

Not applicable.

Course curriculum

1. Snubber circuits and soft switching technique for the switching transistors.

2. DC supplying of the power converters.

3. Electromagnetic compatibility (EMC) in the LF frequency band.

4. Electromagnetic compatibility (EMC) in the HF frequency band.

5. Magnetic phenomena in the power electronics.

6. Optimal design of the chokes with the ferromagnetic core and the air gap.

7. Optimal design of the air coils and reactors.

8. Transformers: mathematical models, equivalent circuit, substitute circuit.

9. Voltage transformer. Current transformer. Power pulse transformers.

10. Power converters with the pulse transformer (switch-mode supplies).

11. Single-end forward converter.

12. Double-end forward converter.

13. Current sensors. Rogowski belt.

Aims

Special types of the power converters. Very good knowledges for design of the all magnetic circuit in the power electronics.

Specification of controlled education, way of implementation and compensation for absences

The attendance at the all numerical and laboratory exercises is required.

#### Type of course unit

Fundamentals seminar

26 hours, optionally

Teacher / Lecturer

eLearning

**eLearning:** currently opened course