Relay protection output circuit and output control method thereof

Abstract

The invention discloses a relay protection output circuit and an output control method based on the relay protection output circuit. The relay protection output circuit comprises a CPU, an FPGA, a starting control unit, an output control unit and a relay driving unit. The CPU is connected with the FPGA through a data bus; the CPU is connected with the starting control unit through a starting control signal line; the FPGA is connected with the output control unit through an output bus and a latch signal line; the output signal of the output control unit and a master control signal sent by the CPU are transmitted to the relay driving unit; and the relay driving unit is connected with the starting control unit through a driving power source line. According to the relay protection output circuit and the corresponding output control method, the anti-interference capability of the output circuit and the reliability of the output circuit can be effectively improved.

Description

technical field [0001] The invention belongs to the field of relay protection, and in particular relates to a relay protection opening circuit and an opening control method thereof. Background technique [0002] Microcomputer relay protection devices have developed rapidly since the 1990s. It has developed from a traditional single-function protection relay to an intelligent device integrating protection, control, measurement, communication, human-computer interaction and other functions. With the rise of smart substations and the further improvement of industrial control requirements, there are more and more requirements for the output of medium and low voltage protection devices, and the requirements for the reliability of the output circuits are also getting higher and higher. [0003] The existing control methods for relay protection devices are as follows: [0004] 1. The traditional output control method of medium and low voltage protection devices is to use the IO p...

AI Technical Summary

Problems solved by technology

[0006] However, in the complex electromagnetic environment of the actual engineering site, the latch circuit has the risk of being easily disturbed and incorrectly latched

If the LE latch signal of the latch chip encounters an interference pulse, the latch chip will latch the wrong input signal into the output drive circuit and cannot recover automatically

[0007] Although the CPU can solve this problem by constantly actively refreshing the latch state during operation, this method will take up a lot of CPU execution time and reduce CPU operating efficiency

[0008] 3. Usually, the driving signal of the output relay is driven by a single signal, and the wrong flip of a single signal can cause the state of the relay to change. The reliability of the entire output control circuit is low, and the anti-interference ability is weak

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