Typical Fault Simulation And Optimum Design Method Of On-load Tap-changer Based On Virtual Prototype

Transformer is the key link of substation,and it is an indispensable part of power grid.The stable operation of transformer is of great significance to ensure the safety of power grid.As the only movable part of on-load tap changer,on-load tap changer can realize smooth voltage regulation,and occupies an important position in power network.With the widespread use of on-load tap-changers,power accidents often occur due to the fault of tap-changers,which seriously affects the quality of power supply and the stability of power system,and brings huge economic losses.Therefore,it is of great significance to study the fault mechanism and optimal design of on-load tap changer.In this paper,a virtual prototype of on-load tap-changer and a multi-dimensional optimization design method are proposed for the first time,and a vibration detection platform of on-load tapchanger is built to verify the model and data.The main work is as follows:(1)Fault types and data of on-load tap-changers at home and abroad are extensively investigated,and the principle of coordination of electrical and mechanical actions of onload tap-changers is analyzed.On this basis,fault data of on-load tap-changers are summarized and summarized.Typical fault types of on-load tap-changers,as well as typical fault characteristics and fault mechanism are obtained.(2)In this paper,a hybrid modeling method of on-load tap-changer virtual prototype is proposed for the first time by virtue of virtual prototype technology and mathematical constraint equation.Based on this method,a virtual prototype model of on-load tapchanger is built,and the internal mechanism and principle of the tap-changer are introduced in detail.The results show that the hybrid modeling method can greatly reduce the workload of on-load tap-changer modeling,improve the efficiency of modeling and shorten the research and development cycle on the premise of ensuring the correct and effective construction of virtual prototype.(3)In order to extract the tap-changer vibration signal,a finite element sub-model is built on the basis of the virtual prototype of on-load tap-changer.Combining with the basic dynamic equation,the high frequency acquisition of the transient vibration signal is realized by the contact control of micro-transient solution method and penalty function method.A test platform for vibration detection of on-load tap-changer is built,typical fault vibration signals are collected,and the vibration signals are compared with the simulation ones by using the method of variational mode decomposition.The results show that the experimental and simulated vibration signals are in good agreement,which proves the correctness of the proposed prototype construction and high frequency signal acquisition method,and provides a new solution for fault diagnosis and identification of on-load tap changer.(4)Based on the research results of on-load tap-changer virtual prototype,a multidimensional optimization design method of on-load tap-changer is proposed.In this paper,a four-module optimization design procedure,i.e.target module,prototype connection module,numerical calculation module and optimization design module,is proposed in a fast and easy-to-understand module design form.At the same time,according to the structural attributes and characteristics of on-load tap changer,the calculation and analysis methods in different modules are introduced.Based on the example of mechanical fatigue optimization of on-load tap changer,the multi-dimensional optimization design method is validated.The results show that the multi-dimensional optimization design method proposed in this paper can meet the design requirements of different optimization types,realize the fast grasp of the optimal design scheme,and greatly enhance the overall stability of the on-load tap-changer system.