A Voltage/potential transformer (PT) is an instrument used to transform voltage, mainly used to convert high voltage into low voltage suitable for measurement and protection. The working principle of a voltage transformer is similar to that of a transformer, but its capacity is relatively small, usually only a few tens or hundreds of volt amperes. It is mainly used in transmission and power supply systems such as power plants and substations. Basic structure and working principle Potential/Voltage transformers are mainly composed of primary coils, secondary coils, iron cores, and insulation materials. When a voltage is applied to a primary coil, magnetic flux is generated in the iron core, and according to the law of electromagnetic induction, a corresponding voltage is generated in the secondary coil. By changing the number of turns of the primary or secondary coil, different voltage conversion ratios can be obtained. Main function Voltage conversion: Convert high voltage to low voltage, usually 100V or 100/√ 3V, for measurement and protection purposes. Electrical isolation: Isolate high voltage from secondary equipment to ensure equipment and personal safety. Standardization: Standardize measuring instruments and protective devices, simplify equipment structure, and reduce costs. classification Potential/Voltage transformers can be classified into dry-type, cast type, oil immersed type, gas filled type, etc. according to their insulation structure; It can be divided into single-phase and three-phase according to the number of phases; According to the number of windings, it can be divided into double winding and triple winding; It can be divided into indoor and outdoor types according to the installation location. Application scenarios Potential/Voltage transformers are widely used in power transmission and supply systems such as power plants and substations to measure line voltage, power, and electrical energy, as well as to protect valuable equipment and motors in the event of line failures. In addition, it can provide safety and convenience when measuring high voltage.
