Equipment Introduction
MEJFD-1S Partial Discharge Tester is a new type of digital partial discharge test instrument developed by our company. It retains the of the product while reducing the size, and the performance has been further optimized. It adopts a 10.1-inch touch screen instead of the traditional oscilloscope and physical operation method, making it more functional, more convenient to use, and more reliable in performance. The instrument uses a 32-bit high-performance single-chip micro circuit combined with touch screen operation, which not only improves the service life of the operation but also has the following functions: one-key automatic calibration; high voltage test voltage div ratio can be set; serial port communication to upload test data. The instrument has the characteristics of high detection sensitivity, wide range of applicable test pieces, large dynamic range of the amplification, multiple frequency band combinations (nine types), and strong anti-interference ability. This instrument, when used in conjunction with the calibration pulse generator and the input unit, is practical partial discharge test instrument widely used by power departments, manufacturers, and research institutes.
When the test sample CX produces local discharge under the test voltage, an impulse current is generated through the coupling capacitor Ck, and the pulse is picked up by the input unit. After amplification by the low-noise preamplifier, filtering by the filter amplifier to select the desired frequency band, and amplification by the amplifier (to the desired amplitude), a visible discharge pulse is generated on the elliptical scanning baseline of the touch screen, and the pulse peak value is displayed simultaneously. The time window selects a segment of working time within each cycle of the test voltage, during which the corresponding display area of the touch screen is marked in red. It can avoid the interference of phases, which is a conventional method for testing the amount of discharge.
When a known amount of charge is injected into the test sample CX with a JZF-type pulse generator, the value displayed by the amount of discharge can be made consistent with the injected charge by automatic correction, so that the amount of discharge of the test sample can be directly from the touch screen during the voltage test without calculation, which is very convenient.
1、The equivalent capacitance range of the testable samples is 6pF to 250µF.
2、Measurement range: 0.1 pC - 10000 nC
3. Number of channels: Single channel
4. Detection sensitivity and allowable current (see Table 1)
|
Input unit Serial number |
Tuning capacitor range |
Sensitivity (pC) (Unbalanced circuit) |
Permissible current RMS value |
|
|
Unbalanced circuit |
Balanced circuit |
|||
|
1 |
0～25～100pF |
0.02 |
30mA |
0.25A |
|
2 |
25～100～400pF |
0.04 |
50mA |
0.5A |
|
3 |
100～400～1500pF |
0.06 |
120mA |
1A |
|
4 |
400～1500～6000pF |
0.1 |
0.25A |
2A |
|
5 |
1500～6000～25000pF |
0.2 |
0.5A |
4A |
|
6 |
0.006～0.025～0.1μF |
0.3 |
1A |
8A |
|
7 |
0.025～0.1～0.4μF |
0.5 |
2A |
15A |
|
8 |
0.1～0.4～1.5μF |
1 |
4A |
30A |
|
9 |
0.4～1.5～6.0μF |
1.5 |
8A |
60A |
|
10 |
1.5～6.0～25μF |
2.5 |
15A |
120A |
|
11 |
6.0～25～60μF |
5 |
25A |
200A |
|
12 |
25～60～250μF |
10 |
50A |
300A |
|
7R |
resistance |
0.5 |
2A |
15A |
Table 1. Detection Sensitivity and Allowable Current Value of Input Unit
5. Elliptical Scan Time Base
(1) Frequency 50/60, 100, 150, 200, 400Hz
(2) Rotation: In increments of 30°, it can rotate up to 120°.
(3) Working method: Ellipse - Sine wave - Straight line
6. Display Unit
It uses a 10.1-inch capacitive touchscreen.
7. Amplifier
(1) 3dB low-frequency end frequency fL : 10, 20, 40kHz (selectable)
(2) 3dB high-frequency end frequency fH : 80, 200, 300kHz selectable
(3) Gain adjustment: coarse adjustment has 6 levels with a gain difference of 20±1dB between levels; fine adjustment range is >20dB.
(4) Asymmetry of positive and negative impulse response <1dB
8. Time window
(1) Window width: Adjustable, 5°～170° at 50Hz
(2) Window position: Each window can be rotated from 0° to 170°.
(3) The two time windows can be opened separately or simultaneously.
9. Pulse peak display
Touchscreen display: shows 1 decimal place (greater than or equal to 10 pC) or 2 decimal places (less than 10 pC), with an error of ±3% (full scale).
10. Test voltage display
(1) Range 150kV
(2) Input impedance: >1MΩ
(3) Display: Touch screen display, displaying to 1 decimal place.
(4) Error: ±1%
11. Test frequency display
Error: less than ±1%
12. Zero-standard system
The zero mark is consistent with all elliptical scan frequencies.
13. Structure
(1) Dimensions: 370mm (width), 460mm (depth), 215mm (height)
(2) Weight: Approximately 12.5 kg
We provide you with free consultation services
Engineers provide guidance for installation and commissioning
Technicians can provide on-site maintenance services and receive regular training
Perfect technical consulting service system
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Address: China Optics Valley No. 1, Fenghuangyuan 2nd Road, Donghu High-tech Development Zone, Wuhan City
whmoen@163.com
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15997412136
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