The current fluctuation and torque ripple caused by brushless DC motor commutation are gaining attention as an intiinsic problem of this type of motor. There is as yet no integrated analysis environment that helps us resolve this problem, and we are obliged to use two separate analysis methods: one is the magnetic waveform and magnetic circuit analysis method employing electromagnetic analysis（JMAG),and the other is the drive control system analysis method employing Matlab/Simulink.

When an electromagnetic field analysis is carried out alone,it is difficult to reflect characteristics of the chive circuit—particularly, to take the reflux diode and current control effects into consideration. To take these parameters into consideration,the user needs to develop custom software. In an independent analysis of the drive control system using Matlab/Sirnulink, we use the results of electromagnetic field analysis (back EMF waveform and motor impedance) as an approximate model of the motor to analyze the drive circuit and current control. However, some factors that are difficult to modelize–such as back EMF waveform distortion caused by the influence of the armature reaction–cannot be taken into account. At present, therefore, it is impossible to evaluate and optimize the motor drive control system as an integral system.

Nevertheless, a coupled simulation using JMAG and Matlab/Simulink can pave the way to establishing an integrated analysis environment for the evaluation and optimization of motor drive control systems. Due to limited time and restricted technology disclosure, this paper only introduces example of our coupled simulation carried out on a simple brushless DC motor drive control system. Specifically, a motor model of JMAG was integrated into a drive control system model (in which inverter circuit and current detection are included) that has been configured using Matlab/Sirnulink. This integrated simulation model was used to show how the parameter design of a current control system could affect the reduction of current and torque fluctuations.

In the future, we hope to introduce GUI for the setting of conditions and automate the model integrating process to complete this as an integrated analysis environment that can be used in the preliminary system studies of new product development or the evaluation/optimization of ongoing system development.

Keywords: Electromagnetic field analysis; drive control systems; coupled simulation; integrated analysis environment; integrated development environment