Electric locomotive electronic mutual inductor and application method thereof

Abstract

The invention discloses an electric locomotive electronic mutual inductor and an application method thereof. The mutual inductor comprises a voltage dividing circuit, an overvoltage protection circuit, a high voltage side photoelectric isolation processing unit circuit and a low voltage amplification circuit, wherein the output end of the voltage dividing circuit is connected with the input ends of the overvoltage protection circuit and the high voltage side photoelectric isolation processing unit circuit; the overvoltage protection circuit is grounded; the output end of the high voltage side photoelectric isolation processing unit circuit is connected with the low voltage amplification circuit; the voltage dividing circuit draws electricity from a high voltage contact network and directly divides high voltage into low voltage AC signals, and the voltage, after photoelectric isolation and signal reduction processing by the high voltage side photoelectric isolation processing unit circuit, is also converted into the low voltage AC signals for use of a rear-stage low voltage amplification circuit; and the low voltage amplification circuit is used for shaping of photoelectric isolation signals and at the same time performing feedback on the forward output of a linear optical coupler to enable the conversion precision of the linear optical coupler to meet design requirements. The mutual inductor and the application method, provided by the invention, have the advantages of small size, light weight, loss power consumption, good stability, high safety performance and the like.

Description

technical field [0001] The invention relates to a device for measuring grid voltage, in particular to an outdoor electronic voltage transformer for electric locomotives and its application on electric locomotives. Background technique [0002] As we all know, an electric locomotive obtains 25kV, 50Hz single-phase power frequency AC power from the catenary, and the high voltage of the catenary is sent to the traction transformer inside the locomotive through the pantograph, main circuit breaker, and high-voltage current transformer, while the high-voltage voltage transformer on the locomotive is mainly Realize catenary voltage measurement, power calculation and protection functions. The high-voltage voltage transformer (generally 25kV / 100V or 25kV / 150V) is connected in parallel to the 25kV high-voltage busbar on the roof, and the 25kV is reduced to 100V (or 150V) to provide the voltage source for the display of the locomotive network voltage meter and the locomotive watt-hour...

AI Technical Summary

Problems solved by technology

[0005] 1. The corresponding international or national standards for civilian electronic transformers have just been issued, but there are no corresponding international or national or industry standards for electronic transformers on railway electric locomotives, and it is impossible to identify the various parameter values ​​​​of electronic transformers and Accuracy meets international or national metrology requirements

[0006] 2. In the past, technologies such as electronic voltage transformers, especially high-voltage signal sampling and high-voltage isolation circuit processing (including its voltage-dividing sampling materials and over-voltage protection devices) were still in the exploratory and experimental stage in terms of safety and reliability in civil power systems. It directly affects the safe operation of subsequent circuits and even the entire transmission network. In the railway transportation system all over the world, the safe operation of electric locomotives is the guarantee of the safety of passengers and property. As far as the overall design principles of electric locomotives are concerned, immature use is not considered. technical

[0008] 4. In the past, electric locomotives in my country used traditional electromagnetic voltage transformers to measure the voltage of the primary power grid. The failure rate was not too high when the AC / DC electric locomotives were not used in large quantities in the railway transportation system.

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