The invention discloses a
control system and method with three direct-current motors in forward-direction serial connection. The
system is characterized in that eight IGBT modules form four bridge arms in a two-two serial connection manner, the four bridge arms are parallelly connected to the positive
electrode and the negative
electrode of a direct-current power supply, the three direct-current motors in forward-direction serial connection are serially connected with the four bridge arms, the three direct-current motors are connected with a reference
voltage synthesizer sequentially through aspeed sensor, a
current sensor, a speed adjusting module and a secondary PI controller, the reference
voltage synthesizer is connected with a four-phase
inverter through a PWM pulse
generating unit,the four-phase
inverter is connected with the reference
voltage synthesizer through a current adjusting module and a primary PI controller, the four-phase
inverter is connected to the PWM pulse
generating unit through the reference voltage synthesizer, and
pulse control signals generated by the PWM pulse
generating unit controls the on and off of the eight IGBT modules to drive the three direct-current motors to operate. The
control system is few in used circuit components, simple in structure, stable and reliable in performance and worthy of popularization and application.