Voltage transformers are indispensable electrical appliances in power transmission and power supply systems such as power stations and substations. A precision voltage transformer is an instrument used to expand the limit, measure voltage, power and electrical energy. A voltage transformer is very similar to a transformer and is used to convert the voltage in a line. However, the purpose of the transformer to convert voltage is to transport electrical energy, so it is very large, and is generally calculated in kVA or MVA; the purpose of voltage transformer conversion is mainly to supply power for measuring instruments and relay protection devices. Voltage, power and electrical energy, or maintenance of valuable equipment, motors and transformers when the line is faulty, so the voltage transformer is very small, generally only a few volts, tens of volts, and no more than 1,000 volts.
Why does the voltage have to be converted on the circuit? This is because according to the different situations of power generation, transmission and electricity consumption, the voltage in the line is different, and the difference is too great. Some are low-voltage 220V and 380V, and some are tens of thousands or even hundreds of thousands of volts. In order to directly measure these low-voltage and high-voltage voltages, corresponding low-voltage and high-voltage voltmeters and other instruments and relays must be made according to the size of the circuit voltage. This will not only bring great difficulties to instrument manufacturing, but more importantly, it is impossible to directly manufacture high-voltage instruments and directly measure the voltage on high-voltage lines, which is absolutely not allowed.
The basic structure of a voltage transformer is very similar to that of a transformer. It also has two windings, one is called the primary winding and the other is called the secondary winding. Both windings are mounted or wound around the iron core. There is insulation between the two windings and between the windings and the iron core, so that there is electrical protection between the two windings and between the windings and the iron core. When the voltage transformer is running, the winding N1 is connected in parallel on the line, and the secondary winding N2 is connected to the instrument or relay. Therefore, when measuring the voltage in high-voltage lines, although the primary voltage is high, the secondary voltage is very low, which can ensure the safety of operators and instruments.
Post time: Jul-19-2022