Development Of Intelligent Substation Integrated Power Supply Insulation Detection Device

As an important part of Intelligent Substation, Integrated power supply of smart substation provide safe and reliable power supply for the stable operation of the important work load of the power system such as signal transmission apparatus, relay protection devices. Its stability and reliability bear on the safe production of the power grid. Since the Integrated power supply keep working all the time in the substation and the temperature and humidity of the external environment change gradually, Cable insulation material will be damaged and aging.Equipment will brings about some quality problems in the process of operation such as some poor insulation performance of the component insulation is decreasing, which will further cause serious faults such as direct grounding of DC system. The insulation detection device of Intelligent substation integrated power supply is used to detect insulation faults such as the the negative pole of the branch bus of the DC power supply system grounding and abnormal voltage caused by AC power supply fleeing to DC power supply and so on,its importance is obvious.Because of the long-term absence of perfect technical specifications of the insulation detection of Intelligent substation integrated power supply,the current insulation detection devices which are being used in the smart substation can’t fully satisfy the requirement of the new revised standard. Therefore a new intelligent substation integrated power supply insulation detection device is researched in the paper.Based on the principle of the combination of the DC leakage current method and the balanced bridge method, the equipment is designed on the system architecture of FPGA plus ARM. Besides of function modules of hardware design which contains the sampling circuit, communication unit, data storage unit, man-machine interaction unit,power systems and so on, this paper has completed the system software design so as to achieve the voltage acquisition, leakage current measurement, insulation resistance,automatic measurement and results display and other functions.At last we test the performance of insulation detecting device in a variety of fault scenarios in which the actual substation integrated power supply can occur by simulating.The experimental results show that the intelligent substation integrated power supply insulation detection device has the ability to effectively detect theinsulation status of the smart substation integrated power supply.