By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is t...By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is transformed into plastic deformation work, thus the efficiency of heat excited by friction is low.展开更多
Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic device...Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic devices leads to highly efficient use of energy and materials. Are welding transformer is optimized here. A mathematical model,considering both productive cost and operating losses, which is called or Economical-through-Life transformer, is established. Mixed penalty function method, mixed dispersing variable method and improved orthogonal method have been applied to carry out the optimization calculations. Result shows that the power factor is quite important in an Economi-cal-through-Life transformer, and that some principles must be followed in the design work. Also discussed are the advantages and disadvantages of the three methods. In the end, the prospect of optimum design of welding transformer is forecast.展开更多
The simulation model of an unloading welding transformer was established on the basis of MATLAB software, and the modeling principle was described in detail in the paper. The model was made up of three sub models, i....The simulation model of an unloading welding transformer was established on the basis of MATLAB software, and the modeling principle was described in detail in the paper. The model was made up of three sub models, i.e. the linear inductor sub model, the non linear inductor sub model and series connection sub model controlled by current, and these sub models were jointed together by means of segmented linearization. The simulating results showed that, in the conditions of the high convert frequency and the large cross section of the magnet core of a welding transformer, the non linear inductor sub model can be substituted by a linear inductor sub model in the model; and the leakage reactance in the welding transformer is one of the main reasons of producing over current and over voltage in the inverter. The simulation results demonstrate that the over voltage produced by leakage reactance is nearly two times of the input voltage supplied to the transformer, and the lasting time of over voltage depends on time constant τ 1. With reducing of τ 1, the amplitude of the over current will increase, and the lasting time becomes shorter. Contrarily, with increasing of τ 1, the amplitude of the over current will decrease, and the lasting time becomes longer. The model has played the important role for the development of the inverter resistance welding machine.展开更多
文摘By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is transformed into plastic deformation work, thus the efficiency of heat excited by friction is low.
文摘Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic devices leads to highly efficient use of energy and materials. Are welding transformer is optimized here. A mathematical model,considering both productive cost and operating losses, which is called or Economical-through-Life transformer, is established. Mixed penalty function method, mixed dispersing variable method and improved orthogonal method have been applied to carry out the optimization calculations. Result shows that the power factor is quite important in an Economi-cal-through-Life transformer, and that some principles must be followed in the design work. Also discussed are the advantages and disadvantages of the three methods. In the end, the prospect of optimum design of welding transformer is forecast.
文摘The simulation model of an unloading welding transformer was established on the basis of MATLAB software, and the modeling principle was described in detail in the paper. The model was made up of three sub models, i.e. the linear inductor sub model, the non linear inductor sub model and series connection sub model controlled by current, and these sub models were jointed together by means of segmented linearization. The simulating results showed that, in the conditions of the high convert frequency and the large cross section of the magnet core of a welding transformer, the non linear inductor sub model can be substituted by a linear inductor sub model in the model; and the leakage reactance in the welding transformer is one of the main reasons of producing over current and over voltage in the inverter. The simulation results demonstrate that the over voltage produced by leakage reactance is nearly two times of the input voltage supplied to the transformer, and the lasting time of over voltage depends on time constant τ 1. With reducing of τ 1, the amplitude of the over current will increase, and the lasting time becomes shorter. Contrarily, with increasing of τ 1, the amplitude of the over current will decrease, and the lasting time becomes longer. The model has played the important role for the development of the inverter resistance welding machine.
