When doing the high voltage electric test, often need to use ultra-low frequency high voltage generator, the device combined with modern digital frequency conversion of advanced technology, adopt computer control, fully automated step-up, step-down, measurement, protection, and the advantages of the artificial intervention during automatic booster, was welcomed by the majority of the electricity workers, this paper makes a simple introduction to this.
Ultra-low frequency high voltage generator combined with modern digital frequency conversion advanced technology, microcomputer control, boost, buck, measurement and protection automatic, automatic boost process can be manual intervention. Because it is all electronic, it has the advantages of small size, light weight, large LCD display, clear and intuitive, can display the output waveform, printer output test report and so on. The design index completely conforms to the power industry standard "General technical conditions for special test instruments for power equipment part 4: General technical conditions for ultra-low frequency high voltage generators", which is very convenient to use. At present, mechanical modulation and demodulation is used to generate ultra-low frequency signals at home and abroad, so the sine wave waveform is not standard, the measurement error is large, the high voltage part of spark discharge, heavy equipment, high power high voltage resistance in the second and fourth quadrant of the sine wave discharge shaping, so the overall power consumption of the equipment is large. The product can overcome these shortcomings, through the high voltage side sampling directly to obtain the current, voltage, waveform data, data is true and accurate.
Ultra low frequency insulation withstand voltage test is actually another method of power frequency withstand voltage test. We know that in the power frequency voltage withstand test for large generators, cables and other test items, because of the large capacity of the insulation layer, it is necessary to test the large capacity of the test transformer or resonant transformer. Such a large device is not only heavy and expensive, but also inconvenient to use. In order to solve this contradiction, the power department reduced the test frequency, thus reducing the test power supply capacity. Theory and practice at home and abroad have proved that using 0.1Hz ultra-low frequency voltage test instead of power frequency voltage test can not only achieve the same equivalence, but also greatly reduce the volume and weight of the equipment, the theoretical capacity is about 500% of the power frequency capacity. Greatly reduced testing procedures, more advantages than power frequency testing. That is why this method is widely used in developed countries. Wuhan High Voltage Research Institute has been entrusted by the State Ministry of Power to draft the industry standard uHF "Voltage Test Method for XLPE insulated power cables up to and including 35kV". This method is being popularized in my country, and the instrument was developed in response to this need in my country. It can be widely used in ac voltage withstand test of cable, large high voltage rotary motor and power capacitor.
Main features of the instrument:
1, overvoltage protection: when the output data exceeds the set pressure limit value, the instrument will stop for protection, action development time cost is less than 20ms.
2, overcurrent protection: designed for high and low pressure dual environmental protection.
3, ensure shutdown protection, when the low-voltage side current exceeds the rated current, shutdown protection, action time is less than 20ms.
4. High voltage output protection resistor is designed for lifting body, so there is no need for extra protection outside.
Ultra-low frequency high voltage generator is the high voltage power test equipment that we often need to use in the actual work, so we need to master its main purpose.