Simulation And Optimization Of High Current Density Bus-bar In Switching Power Supply

When alternating current flowing along the conductor, electromagnetic field generate in and out of the conductor. The electromagnetic field cause a redistribution of the current in the conductor, and the current tends to flow on the surface of the conductor.The phenomenon is so-called skin effect. In multi-conductor bus-bar, there are not only the skin effect caused by the conductor itself, but also the proximity effect caused by the interaction between the conductors. Skin effect and proximity effect increase as the frequency of current increases, causing loss increases. With the gradual increase of the capacity of the power system, large current bus-bars appear. In order to design a low-impedance, low loss, good mechanical and thermal properties of high-current bus-bar, a more accurate account of the skin effect and proximity effect is necessary. We can design bus-bar which meet the engineering demand in thermal effects and electromagnetic compatibility through analyze the electromagnetic distribution and thermal effects of bus-bar. This is very important because the accuracy and safety requirements in motor and electrical system are increasing now. This paper studies the bus-bars of switching power Firstly I introduce the finite element method, the principle of electromagnetic induction and then analyze the simulation results and theoretical calculated results of bus-bar. So as to verify the finite element analysis methods is reliable.In modern engineering applications, the situation often occurs, when the variable voltage or current excitation is loaded on bus-bars of mechanical and electrical equipment. The external circuit design and electromagnetic simulation models are combined to create conditions in line with the actual bus-bar model is engineering design trend.This article analyze the theory based on the bus-bar model of17kW switching power, and design the drive circuit(external circuit) to control the working status of the bus-bar. Observe the output waveform of driver circuit by simulation software to verify the reliability of the drive circuit. So this process can ensure that the current flowing in bus-bar consist with the actual conditions. Then I use the means of finite element simulation to make the external drive circuit and bus-bar joint, so that the bus-bar can work under control of the external circuit. Then we can get the simulation results of electromagnetic field, ohmic losses and current density of the bus-bars.To complete the magnetic-thermal coupling and observe the rise of temperature of the bus-bar in the17kW switch power, I put forward the scheme for equivalent conversion of loss. The transient field results obtained by the coupling simulation will be calculated to get the average power loss. Based on equivalent loss, establish fitting current in eddy current field.When the bus-bar model work under the excitation, the average power loss is the same as the calculated one before. Import the volume loss as heat source, simulate the bus-bar steady temperature at work. In addition, this paper based on the completion of the process of the field-circuit-thermal multi-coupling, according to the relationship among bus-bar electromagnetic induction, loss and its structure, discussed and verified the optimization program. And determine the bus optimization program ultimately, through the bus-bar structure optimized to reduce the skin effect and proximity effect, reducing the loss and temperature rise.