Brief description of microcomputer relay protection and routine maintenance of safety devices

.1 Microcomputer protection device to take electromagnetic interference protection measures

In the transformation of substations, electromagnetic type protection must be replaced with micro-computer protection. Technical measures must be taken to prevent electromagnetic interference. That is, strict implementation of the installation conditions of the microcomputer protection device, installation of cable with shielding layer, and the shielding layers at both ends must be grounded. To prevent the long line, one end is grounded, the other end will generate voltage and current due to electromagnetic interference, causing the microcomputer protection to refuse to move or malfunction. In order to reduce the probability of faults and errors occurring in the protection device, the microprocessor protection device must optimize the design, reasonable manufacturing process, and the high quality of the device and device. At the same time, techniques such as shielding and isolation must be used to ensure the reliability of the device and thus improve the ability to resist interference.

.2 The grounding of the microcomputer protection device must be strictly performed according to the regulations

The inside of the microcomputer protection device is an electronic circuit, which is easily interfered by strong electric fields and strong magnetic fields. The ground shielding of the enclosure is conducive to improving the operating environment of the microcomputer protection device; the protection of the microcomputer to improve reliability should be to suppress the interference source, block the coupling channel, and increase the sensitivity. The loop anti-jamming capability starts, and the automatic detection technology and fault-tolerant design are used to ensure the reliability of the microcomputer protection device; fault tolerance is error tolerance, and even if a partial error occurs, it will not cause the protection device to malfunction or refuse to move. Fault-tolerant design is the use of redundant equipment online operation to ensure the uninterrupted operation of the protection device. The fault-tolerant technology is designed to replace the high reliability that can not be obtained with conventional designs and ensure the reliable operation of the microcomputer protection device.

3 prevention measures

Some setting of value and important parameter modification of the microcomputer protection set the operation lock on the hardware design. When the operator's password and the guardian's password must be entered correctly, the normal operation can be performed and the name of the operator and the guardian etc. Information is recorded and saved.

.4 Routine maintenance of relay protection devices

(1) The on-duty operating personnel regularly inspects and inspects the relay protection device, and a good record of operation shall be made on the operating conditions.

(2) Establish a post responsibility system so that everyone has a post and each post has someone.

(3) Do a good job of cleaning relay protection devices. Cleaning must be carried out by two persons to prevent accidental collision with the operating equipment, pay attention to maintaining a safe distance from live equipment, and avoid personal electric shock and secondary circuit short circuit and grounding accidents.

(4) The microcomputer-protected current and voltage sampling values ​​are recorded once a week, and the differential current must be recorded for differential protection.

(5) Regularly perform infrared temperature measurement on the terminal block of the protection device, and detect the heat caused by poor contact as soon as possible.

(6) Check and print the printer protected by the computer every month.

(7) Periodically check whether the protection device time is correct every month to facilitate fault analysis after failure.

(8) Regularly check the protection zone and check out the fixed value sheet to verify

WJB330 three-phase relay protection tester can be used for AC test, DC test, low-cycle same-term, time measurement, power impedance, differential test, superimposed harmonics, entire group test, impedance ladder, zero-sequence protection, system setup and other test items .

Three-phase relay protection tester over-voltage relay test using "AC test" program, when the rated voltage of the relay is less than 120V, single-phase voltage can be used as a variable test.