Wuhan GDMK Electric Co., Ltd
Overview:
This device is designed and manufactured for 35kV cable AC withstand voltage test. The reactor is individually designed for multiple units, which can not only meet the test conditions of high-voltage and low-current equipment, but also meet the low-voltage AC withstand voltage test requirements of 10kV cables.
The special AC resonance test system for cables adopts the method of adjusting the frequency of the power supply, so that the reactor and the capacitor under test can achieve resonance, and the high voltage and large current can be obtained on the test product. It is a new method of current high voltage test and The trend has been widely used at home and abroad.
The AC resonance test system uses a dedicated SPWM digital waveform generator chip with a frequency resolution of 16 bits, and the frequency fineness can reach 0.1 Hz at 20 to 300 Hz; it adopts an orthogonal non-synchronous fixed carrier modulation method to ensure that the entire frequency The output waveform is good in the interval; the advanced IPM module is used in the power part to ensure the stability and safety of the instrument under the minimum weight.
The test system consists of a frequency and voltage regulation power supply, an excitation transformer, a reactor, and a capacitor divider.
Technical index:
1. the resonant excitation power supply only needs 1/Q of test capacity, which is 1/10-1/30 of common test unit and reduces the system weight and volume greatly.
2. Rated voltage:
1.108kV---meeting the alternating current withstand voltage test for 35kV cable;
2.Waveform distortion rate of output voltage should be less than 1.0%.
3.The permissible continuous working time is to work for 5 minutes at one time under rated condition.
4.Quality factor of unit itself: Q>50
Advantage:
1.The power capacity needed is reduced greatly.
2.The weight and volume of equipment is reduced greatly.
3.The waveform of output voltage is improved.
4.The large short-circuit current is prevented from burning fault point.
Feature:
1. A large number of cables with voltage levels of 35kV and below are used, and the test workload is large, so this type of withstand voltage test device is small in size and light in weight, and a portable cable withstand voltage test system was born;
2. This system requires that the weight of the parts that a single person can move on-site does not exceed 30kg, and the weight of the parts that two people can move on-site does not exceed 60kg, which is suitable for on-site transportation;
3. The power supply adopts 220V single-phase power supply or 380V single-phase power supply, which is convenient for on-site power supply;
4. The reactor part is made of dry epoxy casting, which is beautiful and reliable, suitable for the requirements of various cables;
5. The withstand voltage test of 110kV and above cables adopts oil-immersed reactors.