TABLE OF CONTENTS | 1. | Does a transformer have an inrush current? |
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| 2. | What is the arrangement of the windings in a transformer? |
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| 3. | Does the main output transformer of a power plant have an effect on the size of the conductors used in the transmission lines? |
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| 4. | What are the relationships between the input and output current and voltage of a transformer? |
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| 5. | Explain the apparent impedance and provide an application for it. |
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| 6. | Does the reactive power have an effect on transmission losses? |
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| 7. | What are the characteristics of reactive power? |
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| 8. | What are the losses in a transformer? |
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Answers
| 1. | A transformer has an inrush (starting) current around 12 times greater than the normal current through the transformer. This inrush normally lasts for about 15 cycles of the ac power. This means that 0.25 s (15 cycles last 0.25 s) after the transformer is started, the current will reach its normal value. |
| 2. | The insulation is installed around the core. The low-voltage winding is installed on the core insulation. This is done to reduce the voltage stress on the insulation. The high-voltage winding is installed around the low-voltage winding with spacers in between them. In other words, the low-voltage winding is installed inside the high-voltage winding. This is done to minimize the flux leakage in the transformer. |
| 3. | The main output transformer of a power plant is normally a step-up transformer. It increases the voltage by at least 10 times. The corresponding decrease in transmission losses is about... |
