TransformersLaajuus (3 ECTS)

Objective

The student understands how a transformer works and knows the selection and dimensioning principles of a transformer. He/she understands the meaning of a transformer equivalent circuit and will be able to use it for fault current and voltage reduction calculations. The student can use the rated values and basic measurement results to determine the equivalent circuit parameter values and calculate the transformer efficiency.

Content

1. Transformer structure and operation
2. Magnetic circuit and saturation
3. Equivalent circuit
4. Equivalent circuit parameter determination
5. Load capacity and efficiency
6. Parallel connection

Qualifications

Electromagnetism
DC Circuits

Assessment criteria, satisfactory (1)

1. The student can describe the operation principle of a transformer and calculate transformer voltage ratio.
2. The student can explain how the magnetic saturation affects the operation of a tranformer.
3. The student knows the structure and purpose of a simplified equivalent circuit of a transformer.
4. The student can determine the equivalent circuit parameters from rated values.
5. The student can calculate transformer rated current.
6. The student knows the conditions for parallel operation of transformers.

Assessment criteria, good (3)

In addition to the previous ones:
1. The student can explain the electric and magnetic behaviour of a transformer in detail.
2. The student can describe different tranformer types and applications.
3. The student knows different transformer connections and the respective drawing symbols.
4. The student knows the impact of harmonics and network disturbance to transformer performance.

Assessment criteria, excellent (5)

In addition to the previous ones:
1. The student masters the transformer equivalent circuit mathematically and is able to explain the transformer behavior with phasor diagrams.
2. The student knows the mechanical structure of different tranformer types.
3. The student is able to estimate the impact of harmonics and network disturbance to transformer performance.