power transformers are widely used in several fields. Industrial automation: Power transformers are extensively used in industrial production to supply different voltage levels for various electric equipment such as motors and robots. Medical equipment: Medical devices like X-ray machines, magnetic resonance imaging (MRI) system, electrocardiogram (ECG) machines require a stable power supply, and power transformers play a significant role in providing it. Additionally, portable medical devices also use power transformers for charging.

What are the similarities and differences of voltage and current transformers? The current transformer is called CT and the voltage transformer is called PT. What they have in common is that they work on the principle of electromagnetic induction, which is used to monitor the electrical circuit: the current of the electrical circuit is monitored through CT, which is the current source of secondary instrument and protection

Voltage transformer - according to the principle of electromagnetic induction type and capacitance type two categories. According to the purpose, voltage transformers are divided into two categories: measurement and protection.

A: The main functions of the transformer are: ① used to insulate the secondary equipment such as instruments and relays from the main circuit. ② It is used to expand the application range of instruments, electrical appliances and other secondary equipment. Voltage transformer installation: ① pay attention to the secondary side do not short circuit. ② One end of the secondary side must be grounded. ③ Pay attention to the installation of the terminal polarity current transformer: ① Do not open the secondary side. ② One end of the secondary side must be grounded. ③ Pay attention to terminal polarity

​The ring indicates the number of primary and secondary windings of the voltage transformer. One primary winding is removed, and the rest are all secondary windings.

Electromagnetic Voltage Transformer (PT) and Capacitive Voltage Transformer (CVT) are widely used in power system. Although capacitive voltage transformers and electromagnetic current transformers commonly used in power grids have mature technology and long-term operation and maintenance experience, their measurement linearity is poor, the transient response speed is slow, and the transient error characteristics of electromagnetic current transformers are not ideal.

The rise and development of intelligent power grid technology has put forward new requirements for voltage and current sensors in power system. Miniaturized non-contact sensors will be the mainstream and need. This paper summarizes the application status of traditional electromagnetic voltage transformers and capacitive voltage transformers, and points out their limitations. On the basis of introducing the D-dot measurement principle in high voltage pulse electrical measurement, an electronic voltage transformer based on self-integrating D-dot sensor is proposed, and it is pointed out that it will be the mainstream trend of voltage signal measurement in power system.

A transformer ​is a device that converts voltage or current proportionally. The function of the transformer is to convert high voltage or high current into standard low voltage (100V) or standard low current (5A or 1A, both referring to the rated value), so as to achieve the standardization and miniaturization of measuring instruments, protection equipment and automatic control equipment.

In the power system, the role of the current transformer is to change the large current into the small current, isolate the secondary loop connected to the relay and measuring instrument from the high voltage system of the primary current, and convert the primary current to the secondary current value of 5A or 1A standards.