Voltage transformer circuit a

Voltage transformers are widely used in power systems
and are divided into two types: electromagnetic type and capacitive type
. The primary side of the voltage transformer is connected to
the high voltage to be measured, and the voltage on the secondary side is generally
loov, which is used for instrument indication or as a starting power supply for protective action
devices. When using a voltage transformer,
the measuring instrument circuit can be isolated from the high-voltage
circuit
, thus ensuring the safety of people and electrical equipment. The appearance of the voltage transformer
is shown in Figure 5-12a.
    Voltage transformer is a small high-voltage transformer, which can be divided into single-phase and three-phase voltage transformers. Used on high-voltage power lines, the wiring line
is shown in Figure 5-12b. When using voltage transformers, you should pay attention to the following aspects.
    1) The secondary side of the voltage transformer is never allowed to be short-circuited, and it can only be put into operation after passing the withstand voltage test.
    2) Frequently check the voltage transformer for oil shortage, oil leakage, and whether the oil-porcelain bushing is cracked or damaged and other unsafe factors.