Design Of Induction Power Supply For On-line Monitoring Device Of Cable

With the continuous innovation of the power industry and smart grid,on-line monitoring of the work of high-voltage transmission line cable has evolved into a very important task,which requires the installation of adequate monitoring equipment around the transmission cable.But the cable distribution range is very wide,and the vast majority of cables in the suburbs and buried in the ground,usually around the case there is no conventional power supply,so the need to develop a special type of power to ensure that all kinds of equipment to normal operation.For this type of power supply,the current transformer through the primary current sensing to the secondary side,in order to provide sufficient power,this approach can achieve the power of the most ideal;However,because the transmission line cable current changes in a wide range,The first problem is the primary side of the current power supply can not meet the actual demand,the second problem is the original current is relatively large output of the actual voltage can not be well controlled,this article for these The problem is discussed in the following discussion,and then the final results of the study were applied in practice;First of all,for the primary current hour power supply can not meet the actual needs of the problem,can be in parallel to match the capacitor in parallel,so as to effectively improve its power;the use of nanocrystalline materials,silicon steel,iron oxide material advantages,The parameters of the parameters of the known or measurable,it can from a particular low-side current to obtain the maximum power and get the maximum power when the current transformer secondary voltage,matching capacitance and other quantitative quantitative Analysis and calculation in order to rationally design the electrical parameters of the power supply,in order to primary current for this specific value to obtain the maximum power to meet the needs of transmission cable monitoring equipment.Secondly,the actual voltage can not be well controlled when the primary current is relatively large.The bypass switch can be connected in parallel to the secondary side of the current transformer,and then closed in all primary current cycles.The time of closure is moderate,In order to further simplify the design of this paper,the bypass switch can be integrated into the bridge arm of the rectifier circuit,in order to achieve the desired requirements,while the entire work process was carried out in order to further reduce the power supply to the power supply.Comprehensive analysis.In addition,the specific application of the structure and control methods are also studied in depth,and summed up the circuit characteristics.Finally,if the primary current is lower than a certain value,resulting in the actual output power of the power supply is low,can not meet the operation of the equipment.In this case,the solution is to use the backup battery and take the power supply to work together for the monitoring equipment Power,and the output power to achieve the desired value,thereby reducing the equipment on the backup battery dependence.After comparison and research,Buck,Buck-Boost and Flyback topology are the best performers for post-stage DC-DC converters,so that when the primary current is fluctuating,the converter outputs the maximum power required duty cycle significant changes have taken place,and the overall design flow of DC-DC converters has been greatly reduced.