Analogue quantity inputting circuit for transformer substation

Abstract

The invention provides an analogue quantity inputting circuit for a transformer substation. The analogue quantity inputting circuit comprises a transformer of the transformer substation, a current transformer and a voltage transformer, wherein the current transformer and the voltage transformer are connected with the transformer of the transformer substation. The analogue quantity inputting circuit further comprises a convertor connected with the current transformer and the voltage transformer, at least one voltage forming circuit connected with the convertor, a low-pass filter connected with the voltage forming loop, and a sampling hold circuit connected with the low-pass filter. The sampling hold circuit is connected with an AD (Analogue-Digital) converting chip; the AD converting chip is connected with a CPLD (Complex Programmable Logic Device) chip; and the CPLD chip is connected with a controller and an internal memory through buses. The analogue quantity inputting circuit provided by the invention has the beneficial effects that: a current signal of the current transformer is converted into voltage information by arranging an isolation transformer T in a circuit and using a voltage-reducing resistor and a current-limiting resistor; and while, a sampling signal can be effectively guaranteed to be timely, accurate and synchronous by respectively independently arranging the AD converting chip in a sampling process aiming at each sampling channel.

Description

Technical field [0001] The invention relates to an analog input circuit, in particular to a substation analog input circuit. Background technique [0002] With the development of science and technology, the development of substations has also reached a higher level. Integrated automation is also used more and more widely in substations. Among them, the acquisition of physical quantities involved in substations is essential, such as current value, voltage value, and active power. Data such as reactive power and temperature, as we all know, the computer can recognize only digital quantities; the acquisition of the above analog quantities must be supported by a set of circuits, among which imported equipment is often used for the collection of voltage and current values, resulting in cost High, and it brings inconvenience to daily maintenance. Summary of the invention [0003] The purpose of the present invention is to solve the way of collecting and inputting analog quantity in a s...

AI Technical Summary

Problems solved by technology

[0002] With the development of science and technology, the development of substations has also reached a higher level. Integrated automation is also used more and more widely in substations. Among them, the collection of physical quantities involved in substations is essential, such as current value, voltage value, and active power. Data quantities such as reactive power, temperature, etc., as we all know, only digital quantities can be recognized by computers; the acquisition of the above analog quantities must be supported by a set of circuits, and the acquisition of voltage and current values ​​​​often uses imported equipment, resulting in cost High, and it brings inconvenience to daily maintenance

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