A three-DC motor series system and torque control method

Abstract

The invention discloses a series system of three direct current motors and a torque control method. The rotational speed deviation is generated through a PI regulator to generate three current reference signals; the armature currents of three direct current motors are obtained through current sampling and calculation; the three current reference signals are The signal uses the reference torque synthesis algorithm to synthesize four-way reference torque; the armature current of the three DC motors uses the feedback torque synthesis algorithm to become four-way synthetic feedback torque; the four-way torque reference signal and the four-way torque feedback signal The deviations of the four torque hysteresis controllers are respectively input to the reverse input terminals of the four-way torque hysteresis controller, and output a square wave signal whose amplitude upper limit and lower limit are inverse numbers; the torque hysteresis controller is converted to The adjusted signal is generated by PWM to generate four pairs of two-two complementary level signals, which are input to the four-leg eight-switch inverter to realize the independent four-quadrant operation of three DC motors connected in series. The invention simplifies the system and improves the stability and response speed of the system.

Description

technical field [0001] The invention belongs to the technical field of multi-motor control, and in particular relates to a series connection system of three DC motors and a torque control method. Background technique [0002] With the progress of society and the development of science and technology, multi-motor control technology is constantly improving and innovating. Due to the advantages of good speed regulation performance, large speed regulation range and smooth speed regulation of DC motors, it is widely used in industrial production and mechanical equipment. Application, multi-DC motor control technology is developed on the basis of single DC motor control technology. Compared with single DC motor control technology, multi-DC motor control technology also needs to consider the relationship between the speed, torque and current of each DC motor At the same time, reducing the cost of the motor circuit system is also an important research direction. [0003] Normally, ...

AI Technical Summary

Problems solved by technology

[0003] Normally, a DC motor requires two-leg four-switch inverter modules to achieve four-quadrant operation. To drive three DC motors and achieve independent four-quadrant operation, a six-leg twelve-switch inverter is required module, which makes the drive circuit very complicated and the cost is high; at the same time, in order to realize the smooth speed regulation of the three DC motors and prevent the current and torque from fluctuating too much, it is necessary to perform double closed-loop control of speed and current. The traditional control method It calculates the deviation of speed and current through two PI regulators connected in series, and then generates twelve control signals through PWM to generate twelve control signals and input them to the six-arm twelve-switch inverter to realize the three-phase inverter. A DC motor runs independently in four quadrants. The circuit system of this control system and method is relatively complicated, the response speed of current and torque is slow, and the control effect is general.

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