Parametric Design Of Velocity Transducer In Vacuum Circuit Breakers

The state parameter detection of the vacuum circuit breaker which is important circuit equipment is necessary means to ensure the normal and stable operation in electric power system.The speed of dynamic contact is the key of the status parameters detection.The article mainly conducted simulation analysis and parametric design of the velocity sensor in different voltage grades.The structure and sizes of the switching velocity sensor were chosen and analyzed in10 kV,35kV,72.5kV voltage grades.First of all,the distribution of the magnetic field was analyzed through the finite element analysis software.To make better use of the magnetic field,the simulation analysis of one-coil structure and double-coil structure were compared in 10 kV and 35 kV voltage grades.The coil height is small because the opening range of the vacuum circuit breaker is small.If divided into more coil structure,the structure is compact and not easy configuration.To further optimize the structure,the simulation analysis of double-coil structure and four-coil structure were compared considering the larger opening range in 72.5kV voltage grade.The final result shows that the double-coil structure is of best performance in all three voltage grades.Using Ansoft Maxwell 3D parametric analysis module,the simulation analysis of the important parameters were conducted in the three voltage grades.The sensitivity and linearity are the main performance index of the switching velocity sensor.Based on the theory of a linear relationship between the switching speed and the output voltage in a certain range,the sensitivity analysis was focused on in the simulation analysis.Using the output voltage peak to represent the sensitivity of the sensor,the geometry sizes were designed through the contrast sensitivity and linearity validation.In the end,the parametric design of switching velocity sensor was completed.The use of parametric design method is put forward to solving the inefficient and repeatable problems of velocity sensor in design work.The parametric design of velocity sensor was conducted based on Visual C++ tools and the secondary development of AutoCAD ObjectARX.Through the programming and debugging of the software,the users only need to input or modify the corresponding performance parameters to get the desired 2D graphics while the optimal sizes in different voltage grades were stored in the database andthe human-computer interaction interface was established.At the same time,the design realized the reading function of the geometry parameters in the database and the function of the automatic drawing.