Identification control method of rotational inertia of motor

Abstract

The invention belongs to the air-conditioner control technical field and discloses an identification control method of the rotational inertia of a motor. With the method adopted, problems in automatic acquisition of the rotational inertia of a variable frequency motor can be solved. According to the method, the accelerated velocity and acceleration time of motor rotation velocity in two stages are controlled; motor d / q-axis current corresponding to each fluctuation period of a load torque in each stage is sampled according to the periodicity of the fluctuation of the load torque of the rotor of the motor; and the rotational inertia of the motor is obtained according to the relations of the motor torque and the current, and a motor dynamic equation model. The method of the invention is suitable for determining the rotational inertia of the motor of an air conditioner.

Description

technical field [0001] The invention relates to an air conditioner control technology, in particular to a motor inertial identification control method. Background technique [0002] The traditional variable frequency motor control technology requires the motor manufacturer to provide parameters such as the moment of inertia of the motor, which is determined by the motor dynamics equation Determined, where J is the moment of inertia of the motor, T e is the torque, T l is the load torque, B m is the viscous friction coefficient, and ω is the mechanical angular velocity of the motor. When a large number of different motors need to be controlled, the motor parameters are often stored in a similar EEPROM, and the control program is kept unchanged, which can solve the control of motors such as different compressors, but this method has the following technical problems: one is the need EEPROM increases the cost of hardware. Second, when the user’s inverter air conditioner has...

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Problems solved by technology

When a large number of different motors need to be controlled, the motor parameters are often stored in a similar EEPROM, and the control program is kept unchanged, which can solve the control of motors such as different compressors, but this method has the following technical problems: one is the need EEPROM increases the cost of hardware. Second, when the user’s inverter air conditioner has a problem and needs to be repaired, if the original control board is replaced with a new control circuit or new control software, the specific parameters of the motor may not be known. , unable to quickly replace the motor control circuit and control software

[0004] 1) formula itself is not accurate enough, and all subsequent conclusions are not accurate enough, this is due to the formula Even if ignore B m The term ω cannot obtain the formula

[0005] 2) formula The requirement that "the acceleration times of the first acceleration stage and the second acceleration stage are both 10 milliseconds" is based on making a difference between the formula (2) of the first acceleration stage and the formula (3) of the second acceleration stage to obtain the moment of inertia J, Because in practical applications, the change of torque is generally not faster than 20 milliseconds, that is to say, it can be approximately considered that the torque of the first acceleration stage and are equal, obtained under this assumption, since there are assumptions, there may be conditions that do not match the assumptions, so the conclusions obtained are not reliable

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