A method for collecting high reliability analog quantity of relay protection device

Abstract

The invention discloses a method for collecting high reliability analog quantity of relay protection device. An independent ADC chip is used to monitor an analog power supply of the data ADC chip, andthe CPU periodically reads the voltage value of the analog power supply. When the voltage value exceeds the normal operating range allowed by the data ADC chip, the abnormal alarm of the analog powersupply is generated. When the analog power supply is abnormal, the protection logic locks the trip output, and the merging unit locks the SV message output. When the analog supply voltage returns tonormal operation, the protection logic and merge unit exit the latched state. The analog power supply voltage is confirmed after multiple sampling to prevent the misjudgment caused by instantaneous interference. The invention effectively prevents the wrong data output caused by the abnormal analog power supply of the ADC chip, improves the reliability of the analog quantity collection, and prevents the malfunction of the relay protection device by blocking the local protection trip output and the SV message output.

Description

technical field [0001] The invention belongs to the field of relay protection, and in particular relates to a high-reliability analog quantity acquisition method of a relay protection device. Background technique [0002] With the development of substations in the direction of intelligence and localization, relay protection devices integrate local protection and merge unit functions. The local protection adopts conventional sampling and conventional tripping. The analog quantity collected locally is directly used in the protection logic and drives the tripping. The merging unit converts the collected data into a standard SV message and sends it to the subsequent station domain protection. The high integration of device functions puts forward higher requirements for the reliability of device analog acquisition. [0003] Usually, the ADC chip is powered by dual power supplies. The analog power supply supplies power to the chip's internal analog front-end and A / D conversion co...

AI Technical Summary

Problems solved by technology

At present, in the analog quantity acquisition system of the relay protection device, the digital interface of the ADC chip is judged on the working status and the data is checked, which can effectively ensure the reliability of the transmission between the ADC chip and the CPU, while the ADC analog power supply does not do any monitoring. No protection against data errors caused by abnormal analog power supply

When the analog power supply is abnormal, the ADC conversion result is wrong, and the wrong conversion result is sent to the protection CPU, which may cause a malfunction of the protection. When it is sent to the merging unit, it is transmitted to the subsequent stage through the SV, which may cause the protection of the latter stage to malfunction. It is particularly important to monitor the analog power supply and improve the reliability of analog quantity acquisition

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