تێستکردنی فانکشنی دەستگاهە پاراستنەکانی مایکروکۆمپیوتەر: تاییدکردنی ڕوونامە و بەدەرب kontrolê
1. Pêşkêşkirina Amûrên Test
Amûrên testê bêtikî yên li ser piramîna pêşkêşkirina cihazên derbarandeweyê hene: testker van derbarandeweyê bêtikî, çavkanekar çendehî, û multimeter.
Ji bo testkirina cihazên derbarandeweyê bêtikî ya bi tenha berbi, hesab dike ku testker van derbarandeweyê bêtikî bikar bibe ku dikare jêrvekirina tenha vêran û tenha çendehî hejmaran da bike û hewceya dema inputs digitalekê taybet bike.
Ji bo testkirina cihazên derbarandeweyê bêtikî ya bi tenha nîşan, yekemîn êger signala samplinga çendehî bi karanîna current transformer (CT) ji bo cihaza derbarandeweyê hatine darbexirin, testker van derbarandeweyê bêtikî bikar bibe. Lakin, êger signala samplinga çendehî bi karanîna sensorê xas bi ser rastî wekheviye, divê çavkanekar çendehî çendehî bikar bibe ji bo apply kirina test current bi ser rastî primary side.
2. Tiştên Dîsa Jî Bînin
Hem amûra test û cabinet divê parastîn bikan bila li virîna ku cihaza derbarandeweyê bêtikî û testker eyn common ground bikan.
Na moduleyên cihaza werîne û na panelên circuit bikin hemî daxuyaniye û ji bo testkirina cihaza derbarandeweyê bêtikî. Eger wexelkirina moduleyê werekî ye, divê şivek werîne, şivek test werîne, û karwan divê body static werîne discharge bike û anti-static wrist straps bikin herêm.
Ji bo testkirina, na high voltage li ser low-voltage û communication terminals werekar bike ji bo change test leads.
Pêşkêşkirina test point bikin ebeqey. Voltage û çendehî leads ji testker neçalîna li ser cihaza derbarandeweyê bêtikî, lakin li ser rastî primary side of the instrument transformers. Ev îmkan dide ku evalûyên signal attenuation ji bo acquisition û test completeness.
3. Têvibîna Pêşberî Ji Bo Test
Bînin manuala cihaza derbarandeweyê bêtikî an test procedure. Verify consistency among the manual, device nameplate, actual wiring diagrams, and the system’s voltage and current transformer ratios.
Bînin manuala testker van derbarandeweyê bêtikî û bêzînin operation û bêzînin before testing. Avoid incorrect operations that could subject the protection device to excessive voltage or current, potentially causing damage.
Secure all screws and quick-connect modules of the protection device to ensure reliable connections.
Access the protection menu to set protection settings. Fully understand the meaning of each setting value, organize and label the setting sheet for easy verification later.
4. AC Circuit Calibration
Apply test current at the secondary side of the CT in the cabinet according to the wiring diagram. Mark and store removed bolts properly. Voltage analog testing can be performed at terminal blocks, but ensure voltage does not propagate to busbars.
Adjust the magnitude and phase of voltage and current on the tester. After applying test values, record both the sampling values displayed on the device’s LCD and the actual values from the tester. The error between the two should be less than ±5%. Record data at three points: ascending (0%, 50%, 100%) and descending (100%, 50%, 0%). The displayed values should show no significant difference between up and down tests. Use the following table format for recording.
5. Digital Input/Output (DI/DO) Checks
Digital input/output checks should be performed together with functional tests.
5.1. Digital Input (DI) Check
Digital inputs of microcomputer protection devices include two types. The first is hard contact inputs—external switch contacts directly connected to the device. When the external contact closes, the corresponding defined signal appears on the display. The second is soft contact inputs—internal logic responses, such as a "overcurrent trip" signal displayed on the panel when an overcurrent fault occurs.
DI checks must be performed one by one according to the drawings. Operate associated equipment to change contact states. The displayed status on the LCD or cabinet indicator lights should change accordingly. To ensure reliable operation, each digital input should be tested at least three times.
Never simulate contact closure directly at the backplane terminals of the protection device. Only when the system fails to display or incorrectly displays equipment status should terminal simulation be used to determine whether the fault lies in the protection device, wiring, or equipment.
5.2. Digital Output (DO) Check
DO contacts are also divided into hard and soft types. Hard DO status can be measured with a multimeter. Soft DO status changes must be judged based on logical behavior.
5.3. Digital Signal Checks
Alarm Signal Contact Check: Simulate corresponding faults according to logic. If an alarm is expected but not displayed or incorrect, the device is faulty. For example, simulating a PT fuse failure should result in "PT fuse failure alarm" on the LCD, illumination of the "Alarm" LED, and activation of the "Signal Relay." Alarm signal contacts are momentary.
Trip Signal Contact Check: Trip signal contacts are soft contacts. After a protection trip action, the LCD should display "xx protection trip," the CPU should illuminate the "Trip" LED, and activate the corresponding "Trip Signal Relay." The trip LED and central signal contacts are latching (maintained).
Trip Output Contact Check: Trip output contacts are hard contacts. After a trip action, the protection device activates the trip output relay, closing the trip output contact. These contacts are latching (maintained).
6. Protection Function Testing
Protection function testing is the core of microcomputer protection device testing, focusing on verifying correct setting values, trip time, and output performance.
Definite-Time Protection Testing
Approach Method: Disable other protection functions to prevent false tripping. Set the time delay to 0s. Use the tester to approach the set trip value in 0.1A steps until the device issues a trip command. Record the actual operating value, which should be within ±5% of the set value. Then set the time delay to the specified value and apply the recorded actual operating value. The measured trip time should also be within ±5% of the set time.
Fixed-Value Method: Disable other protections. Apply 0.95×, 1.05×, and 1.2× the set trip value. Protection should not operate at 0.95×, must operate at 1.05×, and trip time should be tested at 1.2×. The measured time should be within ±5% of the set time.
6.2. Inverse-Time Protection Testing
Disable other protections. Apply a test value corresponding to a point on the inverse-time curve. Measure the protection operation time and compare it with the theoretical time calculated from the formula. The error should be within ±5%. It is recommended to test at five different points.
Post-Test Verification
Verify Setting Values: Due to frequent enabling/disabling during testing, confusion may occur. After completing all tests, two personnel should jointly verify all settings.
Restore Removed Wiring: Restore all disconnected wires according to drawings or markings, ensuring correct reconnection. When restoring current circuits, avoid reversing CT polarity or connecting protection wires to measurement circuits.
Check Terminal Block Links: Reconnect any opened links on terminal blocks and have them inspected by a designated person. Even if connected, tighten with a screwdriver to prevent loose connections.
Tighten All Core Wire Terminals: To prevent loosening during testing, all wire terminals must be re-tightened after testing to ensure secure crimping.
