The role of voltage transformers - Solutions - Huaqiang Electronic Network

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The role of the voltage transformer is:
Transforming pressure: The high voltage will be converted into a low voltage (generally 100V) suitable for secondary equipment application according to a certain ratio, which is convenient for standardization of secondary equipment;
Isolation: Electrically isolate the high voltage system from the low voltage system to ensure the safety of the workers and secondary equipment;
1. Convert the high voltage into a standard secondary voltage of 100V or lower in proportion to the protection, metering, and metering devices.
2. Use voltage transformers to isolate high voltage from electrical workers.
3. When the secondary load impedance decreases, the secondary current increases, so that the primary current automatically increases by one component to satisfy the electromagnetic equilibrium relationship between the secondary sides.
For special purposes.
The function of the voltage transformer is: 1. detecting voltage; 2 measuring voltage; 3. eliminating resonance;
In a batch of switchgear, there is often a separate PT cabinet, which is a transformer cabinet, but it does not have to be placed together with the circuit breaker; the PT and the circuit breaker are not very closely connected, and the circuit breaker is only possible when the voltage is under voltage. Action. So if there is not enough space, put it on another cabinet. But the CT is closely connected with the circuit breaker. When the CT detects that there is a short-circuit current, it can send a signal to the circuit breaker to interrupt the short-circuit current. Current transformers must be used when mounting on the feeder.
We can think of voltage transformers as a special transformer with a special structure and use. Specifically, the role of the voltage transformer is to convert the high voltage into a standard secondary voltage of 100V or lower according to the rated voltage ratio relationship. The voltage transformer can be used to isolate the high voltage from the electrical staff. Reduce voltage for measurement and electrical protection.
Although the voltage transformer is also a device that works according to the principle of electromagnetic induction, its electromagnetic structure relationship is opposite to that of a current transformer. The secondary circuit of the voltage transformer is a high impedance circuit, and the magnitude of the secondary current is determined by the impedance of the circuit. When the secondary load impedance decreases, the secondary current increases, so that the primary current automatically increases by one component to satisfy the electromagnetic equilibrium relationship between the primary and secondary sides.
So we can summarize the role of the voltage transformer has the following three points:
1. Pass the voltage and current information of the primary system to the secondary side related equipment accurately;
2. Convert the high voltage and large current of the primary system to the secondary low voltage (standard value 100V, 100/root 3V) and small current (standard value 5A, 1A), so that the measuring, measuring instruments and relays and other devices Standardization, miniaturization, and reduced insulation requirements for secondary equipment;
3. Separate the secondary measuring equipment and the secondary system from the primary system high-voltage equipment in an electrical way, thus ensuring the safety of the secondary equipment and the human body.