CT VT generally refers to the combination of a Current Transformer (CT) and a Voltage Transformer (VT), used together in electrical power systems. The provided reference helps explain their purpose.
Understanding CT and VT
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CT (Current Transformer): A current transformer is used to measure high alternating currents. It produces a reduced current in its secondary winding, which is proportional to the current in its primary winding. This allows safe and accurate measurement of high currents using standard ammeters.
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VT (Voltage Transformer): Also known as a Potential Transformer (PT), a voltage transformer is used to measure high voltages. It steps down the voltage to a lower level suitable for measurement by standard voltmeters and protective relays.
The key takeaway from the provided reference is understanding the ratios of these transformers:
The ratios between the primary and secondary rated voltages and rated currents are the VT and CT ratios.
CT and VT Ratios Explained
| Transformer Type | Ratio | Purpose |
|---|---|---|
| CT | Primary Rated Current / Secondary Rated Current | Steps down high current to measurable levels for instruments and relays. |
| VT | Primary Rated Voltage / Secondary Rated Voltage | Steps down high voltage to measurable levels for instruments and relays. |
Practical Application
In high-voltage power systems, direct measurement of voltage and current is impractical and dangerous. CTs and VTs provide a safe and accurate way to monitor these parameters for:
- Metering: Measuring energy consumption.
- Protection: Detecting faults and initiating protective actions (e.g., tripping circuit breakers).
- Monitoring: System performance and control.
