On-site inspection and design requirements for microcomputer relay protection devices

1. On-site maintenance items of microcomputer relay protection devices include:

(1) Measure insulation

(2) Check the inverter power supply

(3) Check whether the curing procedure is correct

(4) Check the accuracy and balance of the data collection system

(5) Check the switching input and output circuits

(6) Inspection value list

(7) Whole group inspection

(8) Check with primary current and working voltage

According to the impedance at each bus of the system, check whether the linearity of the microcomputer relay protection device can meet the requirements of the system. Special attention should be paid to the relationship between the secondary resistance of the current converter in the microcomputer relay protection device, the current proportional coefficient and the linearity of the microcomputer relay protection device.

The instruments and meters used for inspection should be managed by dedicated inspection personnel. Special attention should be paid to moisture-proof and shock-proof. The error of the instruments and meters should be ensured within the specified range. Before use, you should be familiar with its performance and operating methods. Precision instruments should generally be supervised by someone.

2. Design requirements:

(1) The microcomputer relay protection device should have the ability to resist electromagnetic disturbance.

(2) The microcomputer relay protection tester should be equipped with online automatic detection. When any part of the microcomputer part of the microcomputer relay protection device is damaged, a device abnormality message should be sent out, and the corresponding protection should be automatically blocked when necessary. However, the design of the outlet loop of the protection device should be simple and reliable. It is not appropriate to add components to this loop that may reduce reliability in order to achieve complete self-test of the outlet loop.

(3) All output terminals of the microcomputer relay protection device should not be electrically connected to its weak current system.

(4) The microcomputer relay protection device should be equipped with a self-recovery circuit. When the program is terminated due to interference, it should be able to work normally through self-recovery.

(5) The microcomputer relay protection device should not lose its report when the power is disconnected.

(6) The microcomputer relay protection device should have a time synchronization function.

(7) A unified setting symbol should be specified for the disabled section of the same model of microcomputer relay protection device.

(8) Microcomputer relay protection devices for power systems of 110Kv and above should have the function of measuring the distance to the fault point.

(9) The secondary current transformer used in the microcomputer transformer protection device should adopt star connection, and its phase compensation and current compensation coefficients are realized by software.

(10) Both ends of the same line should be equipped with the same type of microcomputer high-frequency protection.

(11) There should not be too many screen grouping solutions for the same microcomputer relay protection device.

Weshine Electric Manufacturing Co., Ltd.