Research And Development Of Super Low Frequency Withstand Voltage Test System

At this stage, high-voltage insulation theory is still very imperfect; high-voltage electrical equipment at the scene can meet the design requirements, security and reliable operation or not, must go through rigorous testing to verify the insulation. So high-voltage electrical equipment should be carried out strictly testing of the insulation capability in the course of the insulation products falling into a pattern, leaving the factory and running, which make sure the insulation of high-voltage electrical equipment are safe and reliable in the operation at the scene. But in traditional, the insulation test equipment capacity of power frequency is very big for large capacitance product, and it has more destructive; meanwhile DC insulation test can't meet the actual operation requirements. So we need urgently to research and develop a super low frequency withstand voltage insulation test system, which make the electrical insulation preventive testing can be more reliable and run effectively.It is in this situation, this article has conducted the super low frequency withstand voltage insulation test system design, the system can apply to high voltage electrical insulation equipment in 10kV and below the voltage level, the test system will power frequency 50Hz transform into 0.1Hz frequency by the design of frequency conversion circuit, and test equipment will be much smaller, convenient to the insulation test in the workplace, using this system carry out insulation test to the operation of the high voltage electrical equipment on the site will become very convenient and easy.The research of the testing system apply 220V, frequency 50Hz for power supplies, and design a kind of mechanical means priority to the voltage waveform amplitude modulation circuit changes according to the sine, make its waveform envelope modify on the basis of 0.1Hz sine wave cycle, then convey the movement of voltage waveform to the rectifier commutating, finally, through the filtering get the final voltage waveform of the testing voltage, whose frequency is 0.1Hz. The value of the testing voltage can be fixed by transformer, which can output adjustable voltage between 0 to 220V. Then send it to testing transformer and produce 0 to 50kV testing voltage. In order to ensure the safety and reliability of the testing system in the work site, the whole testing system use computer control, the system apply PIC single-chip microcomputer as controlling chip of the core for control, protection and related parameters measurement of the super low frequency voltage test, design the related functional circuits that enables the system be of testing voltage generation and setting function. The experimental simulation results show that the testing system is measured accurately, timing circuit accurately, perfect and reliable protection section, which can get ideal super low frequency waveform of testing voltage.