Control method based on output voltage linear control for linear zone

Abstract

The invention relates to an air conditioner control technology. Aiming at the problem that a vector control method is likely to cause control errors due to tremendous calculated quantity, the invention provides a control method based on output voltage linear control for a linear zone. The method comprises the following steps: firstly, a system calculates a duty ratio according to the fundamental current amplitude of reference voltage and a direct current bus voltage value; then, the system calculates three-phase voltage control time according to the duty ratio value and controls the running of a motor. Through rebuilding vector control, in particular linear zone modulating control and over-modulating control technology from a brand new angle, the zero vector action time calculation is not required, the calculation method is simplified, and the calculation time is shortened. The control method is suitable for over-modulating control of a variable frequency motor.

Description

technical field [0001] The invention relates to an air conditioner control technology, in particular to a PWM duty ratio control method technology of a permanent magnet brushless DC motor. Background technique [0002] The traditional variable frequency motor vector control method, according to the on / off combination method of the upper and lower bridge backs of 6 inverters, forms 8 vectors, the two vectors corresponding to the upper and lower bridge backs are fully open and fully closed are zero vectors, and space vector synthesis is used The method is calculated to control the PWM of the six bridge backs to control the operation of the motor. Dividing a cycle into 6 sectors yields 8 vectors including two zero vectors, as in figure 1 As shown, in each sector, use two adjacent non-zero vectors and the corresponding zero vector to synthesize any vector in the sector, and thus calculate the action time T0 of the two adjacent non-zero vectors and the zero vector . (Permanent...

AI Technical Summary

Problems solved by technology

[0003] The vector control method is not intuitive to control, and it is difficult to establish a concise relationship between input and output. It is necessary to record and distinguish the positions of the six working sectors where the current vector is located. Moreover, the control theory is complicated and difficult to understand, and the amount of calculation is large, and control errors are prone to occur.

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