Variable step size disturbance observation energy-saving control method for three-phase asynchronous motor

Abstract

The invention provides a variable step size disturbance observation energy-saving control method for a three-phase asynchronous motor in the field of motor control, and the method comprises the steps:S10, building a motor active loss polynomial approximation function, selecting a plurality of high-frequency sine disturbance signals, and designing a band-pass filter corresponding to each disturbance signal; S20, starting the motor, and taking the current exciting current as a reference value; S30, injecting a plurality of high-frequency sine disturbance signals into the exciting current; S40,performing filtering by using a band-pass filter to obtain an active loss component corresponding to each disturbance signal; S50, creating a threshold value, and judging the relationship between eachactive loss component and the threshold value; and S60, fitting the polynomial approximation function and solving an extreme point, taking the extreme point as the reference value of the exciting current in the next search, and entering the step S30. The method has the advantages that on the premise that the speed regulation performance of the motor is not reduced, the operation efficiency of themotor is greatly improved, and then the motor can operate in an efficient and energy-saving mode.

Description

technical field [0001] The invention relates to the field of motor control, in particular to an energy-saving control method for variable step size disturbance observation of a three-phase asynchronous motor. Background technique [0002] The three-phase asynchronous motor is a type of motor that is directly powered by a 380V three-phase AC power supply (phase difference of 120 degrees). Since the rotor and the stator rotating magnetic field of the three-phase asynchronous motor rotate in the same direction and at different speeds, there is a slip. Therefore, it is called a three-phase asynchronous motor, which has the advantages of simple structure, low cost, and high reliability, so it has been widely used. [0003] The traditional three-phase asynchronous motor generally adopts the rated excitation method. When the motor load or speed needs to be adjusted, the motor is controlled by frequency conversion and speed regulation, and the excitation current of the motor is gene...

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Problems solved by technology

[0003] The traditional three-phase asynchronous motor generally adopts the rated excitation mode. When the motor load or speed needs to be adjusted, the motor is controlled by frequency conversion and speed regulation, and the excitation current of the motor is generally not changed; since the motor rarely operates under rated conditions , using the rated excitation method under non-rated working conditions will lead to a decrease in the operating efficiency of the motor

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