about brushless dc motor controller of brushless dc motor controller electromagnetic interference loss at the beginning of the design, in order to reduce unnecessary wear and tear in the motor controller, prolong life, save energy, improve efficiency, and cancel the physical carbon brush use sensors for commutation and reached this goal. Although the brushless dc motor controller has many advantages, but also can appear some problems to grip the popularization and development of brushless dc motor controller, electromagnetic interference loss of brushless dc motor controller is only one of them. Loss of electromagnetic interference is one of the biggest problems brushless dc motor controller, the main reason lies in the power semiconductor devices in the process of switch, the device on the current, voltage cause at the same time. In the various losses of brushless dc motor controller, electromagnetic interference generated by the loss, after the power supply with high efficiency to a certain level will not allow to ignore. Energy consumption on the one hand, the electromagnetic interference itself, especially the improvement of power efficiency often require soft switch technology or zero voltage switch or zero current switching technologies, application of the technology of slow down the process of the switch of voltage, current changes in the rate or eliminate the switch process, electromagnetic interference is small, do not need to set as in conventional switching power supply circuit circuit to restrain electromagnetic interference. The same volume of brushless dc motor controller the power dissipation of basically the same, so, want to get more power output, must improve the efficiency, at the same time, improve the efficiency of the power supply can effectively reduce the stress of the power semiconductor devices, is helpful to improve reliability of brushless dc motor controller. So we switch tube of brushless dc motor controller and the output rectifier diodes can achieve zero voltage switch or zero current switch, its efficiency can be improved obviously.
