Intelligent substation, electronic transformer is essential!

Electronic transformer

A device consisting of one or more voltage or current sensors connected to a transmission system and a secondary converter for transmitting a quantity proportional to the quantity being measured, to a measuring instrument, a meter and a relay protection or control device. In the case of a digital interface, a group of electronic transformers share a single unit to perform this function.

Figure 1 Electronic transformer

Electronic transformers meet the development trend of substations

In the process of substation construction at present, automation has gradually become the main construction trend, and the automation system has been continuously expanded, and the traditional instruments and equipment have gradually transitioned into intelligent advanced equipment. Conventional electromagnetic transformer equipment has become the bottleneck of substation intelligent construction, and it is difficult to ensure the development and application of substation's own intelligent technology.

As a product of the development of power technology in the new era, electronic transformers have good stability and can play an effective role in the construction of modern intelligent substations, and have gradually been valued and adopted by the substation construction personnel.

Figure 2 Traditional substation and intelligent substation

Application of electronic transformers in intelligent substations

Electronic transformers are mainly used in secondary circuits and relay protection. Let's take a look at their applications.

Application of electronic transformer in secondary circuit

The use of electronic transformers in the secondary circuit can reduce the use of cable lines and reduce the construction cost of the substation. In the process of substation construction, optical cable is used for signal transmission, and the control of interval and the compact design of substation structure are guaranteed to improve the safety and reliability of the substation system.

Application of Electronic Transformer in Relay Protection

The electronic transformer has a good corresponding ability, and according to the relevant principle of the protection action, since the conventional CT frequency response range is too narrow, it is difficult to perform one-time reproduction of the current waveform. The electronic transformer has a wide frequency response range, which can provide a complete reflection for the high-frequency signal, provide a basis for protecting the action, ensure the accuracy of the action, and the application of the electronic transformer effectively promotes the development of the sampling value differential principle. In general, electronic transformers increase the efficiency and measurement range of the relay protection system, enabling digital signals to be connected to the electrical energy without fault.

Figure 3 All-fiber electronic transformer application site

In the power system, for electronic transformers, the main concern is the accuracy performance such as amplitude error and angular error of the data channel of the electronic transformer. ZLG Zhiyuan Electronic DT6000 series intelligent substation optical digital tester can analyze the sampling information of electronic transformer such as IEC61850-9-1/2, FT3, measure the data on the electronic transformer, and analyze the precision of the electronic transformer. performance.

Based on IEC61850 standard, DT6000 series intelligent substation optical digital tester is widely used in intelligent substation handheld test instruments with voltage levels of 110kV and above. It is used for quick debugging of protection and monitoring devices, intelligent terminals, merging units and transformers in intelligent substation. To facilitate the establishment and maintenance of intelligent substations, it is a Swiss submarine for intelligent substation testing.