Method and device for off-line identification of parameters of three-phase asynchronous motor

Abstract

The invention discloses a parameter off-line identifying method of a three-phase asynchronous motor. Through the current output by an inverter, the connecting method of the three-phase winding of a motor is equivalent to the terminal current of a phase winding, which is detected by a sensor when any two phase windings are connected in parallel and then are connected with the other phase winding in series every time, thereby obtaining the direct voltage and the direct current or the alternating current voltage and the alternating current of the motor winding; the impedance of reverse gamma equivalent circuit of the motor is calculated by the alternating voltage and the alternating current, and then the equivalent rotor resistance, the total leakage inductance and the equivalent mutual induction parameter of the motor are calculated by two impedances under the condition of different frequencies omega 1 and omega 2. The method disclosed in the invention can indentify the motor parameter without the rotation of the motor, thereby avoiding the empty load test required in the process of identifying parameters in prior arts, enlarging the application scope of indentifying the motor parameter and improving the accuracy of the identified motor parameters. The method and the device of the invention are applicable to the motor parameter off-line identification of a three-phase asynchronous motor speed control system controlled by an inverter.

Description

technical field [0001] The invention relates to a three-phase asynchronous motor, in particular to a parameter off-line identification method and device for a three-phase asynchronous motor. Background technique [0002] In recent years, the sensorless vector control technology of induction motors has developed rapidly. In order to carry out coordinate transformation in vector control, it is necessary to know the phase of the rotor flux linkage, that is, the flux linkage angle. In the closed-loop control of flux linkage, in order to keep the amplitude of rotor flux linkage constant, the specific value of flux linkage must be obtained. Therefore, the magnitude of field orientation and flux linkage is critical in vector control. The phase angle and amplitude of the flux linkage are generally obtained through the flux observation model, and the observation model is established based on the mathematical model of the motor. Most of the observation expressions in the observation...

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Problems solved by technology

It is often difficult to directly apply in the actual frequency conversion speed regulation system

First of all, in the speed control system, it is difficult to realize the stalling of the motor rotor; secondly, the load carried by the motor in the industrial field is often unloadable, which cannot meet the no-load test conditions

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