Sine wave PWM control signal generation manner null

摘要

PURPOSE:To use saw tooth carriers having a width which is 1/2 of the period of the sine-wave PWM of an inverter and, at the same time, to make a required PWM command signal coincident with the central point of time of the period of the carriers when the sine-wave PWM of the inverter is calculated. CONSTITUTION:One CPU performs logical operations by successively repeating various kinds of calculation, such as the calculation of the 1/2 value of the pulse width of a required PWM command signal, etc., by dividing the calculation into two routes prior to required points of time by making interrupting operations at every 1/2 period of saw tooth carriers, forms a required pulse by symmetrically distributing the results of the logical operations before and after the central point of time of the corresponding period of the carriers which becomes the required point of time in accordance with the results of the logical operations and setting the logical output between designated two points of time at an 'H' level, and obtains required PWM command signals constituting a pulse string by forming the required pulse at every period of the carriers.