An algebraic modulation method for a three-phase
current source converter is to transform the distribution problem of the
duty cycle into the problem of solving a non-homogeneous linear equation group. The specific steps of the method are as follows: first, according to the
system mathematical model, a non-homogeneous linear equation group of the
duty cycle is constructed, and the general solution of the
duty cycle matrix is obtained by means of the relevant
linear algebra theory; secondly, according to the physical constraints of the duty cycle, the feasible solution range of the free variable is obtained by means of the
geometric method; then, a point is selected in the feasible solution area as the value of the free variable to determine the final duty cycle matrix; finally, according to the specific performance requirements (low loss, low common mode
voltage, low
DC current ripple, etc.), the switch action sequence is reasonably arranged to obtain the driving pulse of each switch. The modulation method avoids trigonometric function calculations, saves
system operation costs, and has the characteristics of easy implementation, high flexibility and strong versatility.