Kötelező:

The aim of the subject is to learn about the causes of electromagnetic transients in the electricity system, the physics of the processes and the consequences of transients. The lectures are intended to provide a deeper understanding of the processes that occur during abnormal operating conditions and short circuits, the design of surge protection, and the operation of some advanced solutions of the power system. The exercises aim to introduce methods for building a simplified physical picture and computational procedures and techniques for simulating transients.

Detailed topics of the presentations:

1. Introduction, subject requirements. Role of electromagnetic transients in power system operation and reliability.

2. Transients in electrical engineering practice, overview of the main characteristics of transients. Properties of distributed and concentrated parameter networks.

3. Wave propagation in ideal one phase-ground system, wave reflection and penetration at discontinuity points.

4. Calculation of wave reflections: overview of Bergeron and Bewley methods.

5. Limitations of methods, effect of trapped charge on the success of reclosing. Defenses against trapped charge. Surge protection of substations with cable entry.

6. Cancellation wave, steady-state waves methods. Clearing of short distance faults.

7. Reference circuits: theory of design of simple and complex reference circuits. Effect of waveforms on the accuracy of the reference circuit.

8. Effect of losses on wave propagation. Effect of drift and corona discharge on wave distortion. Wave distortion effect of lossy earth.

9. Wave propagation in two phase-ground and n-phase systems. Physical explanation of modal waves. Derivation of wave processes in a multi-conductor realistic system from the transients of one phase-ground system.

 

10. Electromagnetic compatibility I: (EMC) concepts, classification of disturbances, propagation modes.

11.Electromagnetic compatibility II: Earthing systems of substations, cable lines, transmission lines, effect of grounding on transient and earth fault potential rise. Review of international practice, methods of calculating earth potential rise. Sectioning transients, substation shielding solutions.

12. Transients in synchronous generators: transient characteristics of three-phase symmetrical short circuits

13. Synchronous generator transients: transient characteristics of asymmetrical short circuits

14. Exam preparation

 

1. Investigation of transients of simple circuits with concentrated parameters.

2. Investigation of wave reflections.

3. Application of the Bergeron method.

4. Application of the Bewley method, cancellation wave and steady state waves principles.

5. Establishing reference circuits.

6. Wave propagation in two conductor-ground systems.

7. Transients in electrical machines.