Voltage transformer is a device used for voltage measurement, protection, and control in power systems, with functions of voltage isolation and signal conversion. Its strong voltage isolation capability and safety reliability are mainly reflected in the following aspects:

1. Electrical isolation capability

Principle: Voltage transformers couple the voltage signal from the high voltage side to the low voltage side through electromagnetic induction or capacitive voltage division, achieving electrical isolation between high and low voltage.

Function:

Prevent high voltage from being directly transmitted to measuring or control equipment, and protect personnel and equipment safety.

Avoid interference from high-voltage systems on low-voltage electronic equipment.

Isolation strength: The primary side (high voltage side) and secondary side (low voltage side) of the transformer have high insulation strength and can usually withstand overvoltage several times the rated voltage.

2. 安全性保障

Insulation design:

High insulation materials (such as insulation paper, transformer oil, SF6 gas, etc.) are used between the primary and secondary windings of the voltage transformer to ensure that breakdown or flashover will not occur in high voltage environments.

The insulation resistance of the primary and secondary sides is usually required to be greater than 100M Ω to ensure minimal leakage current.

Overvoltage protection:

Equipped with overvoltage protection devices to prevent damage to transformers caused by lightning strikes or overvoltage operations.

Grounding design:

The secondary side is usually designed as a single point grounding to avoid the formation of circulating currents and ensure measurement accuracy and safety.

3. Reliability characteristics

Strong anti-interference ability:

Voltage transformers achieve signal transmission through electromagnetic induction or capacitive voltage division, and have strong resistance to electromagnetic interference.

High precision:

The ratio difference and phase difference (angle difference) of the transformer are strictly calibrated and can usually meet the accuracy requirements of 0.2, 0.5, or even higher, ensuring the accuracy of the measurement results.

Long term stability is good:

Adopting high-quality insulation materials and winding design ensures stable performance during long-term operation, and is not prone to aging or failure.

4. Safety and reliability in application scenarios

Power system protection:

Voltage transformers provide reliable voltage signals for relay protection devices, ensuring quick circuit disconnection in case of faults and preventing accidents from escalating.

Measurement and Measurement:

Used for voltage signal acquisition of devices such as electric energy meters and voltmeters, ensuring measurement accuracy and safety.

Substation automation:

In smart substations, transformers provide isolated voltage signals for measurement and control devices, supporting remote monitoring and automation control.